Unicameral bone cyst: Difference between revisions

Jump to navigation Jump to search
(Removed redirect to Simple bone cyst)
Tag: Removed redirect
No edit summary
 
(12 intermediate revisions by 2 users not shown)
Line 4: Line 4:
{{CMG}}; {{AE}} {{Rohan}}
{{CMG}}; {{AE}} {{Rohan}}


{{SK}}  
{{SK}} Simple bone cyst; Traumatic bone cyst, UBC


==Overview==
==Overview==
Unicameral bone cyst (UBC) constitute approximately 3% of all [[bone tumors]]. Adolescents and children are most affected by unicameral bone cyst. The age distribution of unicameral bone cyst is between 5-15 years. Men are more commonly affected compared to women, with a 2:1 ratio. In 1942, Jaffe and Lichenstein later recognized it as a distinct entity. The exact [[pathogenesis]] of unicameral bone cyst is not fully understood. Unicameral bone cyst may have association with [[genetic]] abnormalities on [[chromosome 4]], [[Chromosome 6|6]], [[Chromosome 8|8]], [[Chromosome 16|16]], [[Chromosome 21|21]], and both [[Chromosome 12|chromosomes 12]]. The [[bones]] often involved are proximal [[femur]], distal [[tibia]], [[Ilium (bone)|ilium]], [[calcaneus]], and occasionally [[Metacarpus|metacarpals]], [[Phalanx bones|phalanges]], or distal [[radius]]. Unicameral bone cyst typically occur in the [[metaphysis]] adjacent to the physis of the [[long bones]]. The hallmark of UBC is [[pain]], [[swelling]] and pathological [[Bone fracture|fracture]]. The mainstay of treatment for UBC is [[surgery]] in form of [[curettage]] and [[bone grafting]].


==Historical Perspective==
==Historical Perspective==
[Disease name] was first discovered by [name of scientist], a [nationality + occupation], in [year]/during/following [event].
*In mediveal times, Lagier et al identified a unicameral bone cyst in the [[femur]] from the remains of a child.<ref name="pmid3317251">{{cite journal| author=Lagier R, Kramar C, Baud CA| title=Femoral unicameral bone cyst in a medieval child. Radiological and pathological study. | journal=Pediatr Radiol | year= 1987 | volume= 17 | issue= 6 | pages= 498-500 | pmid=3317251 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3317251  }} </ref>
 
*In 1891, Virchow reported it as “cystic structures” that resulted due to anomalies in the local [[circulation]].<ref name="pmid10951110">{{cite journal| author=Wilkins RM| title=Unicameral bone cysts. | journal=J Am Acad Orthop Surg | year= 2000 | volume= 8 | issue= 4 | pages= 217-24 | pmid=10951110 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10951110  }} </ref>
The association between [important risk factor/cause] and [disease name] was made in/during [year/event].
*In 1942, Jaffe and Lichenstein later recognized it as a distinct entity.<ref>Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg. 1942. 44:1004-25.</ref>
 
In [year], [scientist] was the first to discover the association between [risk factor] and the development of [disease name].
 
In [year], [gene] mutations were first implicated in the pathogenesis of [disease name].
 
There have been several outbreaks of [disease name], including -----.
 
In [year], [diagnostic test/therapy] was developed by [scientist] to treat/diagnose [disease name].


==Classification==
==Classification==
There is no established system for the classification of [disease name].
Unicameral bone cyst can be classified based on imaging findings.
 
OR


[Disease name] may be classified according to [classification method] into [number] subtypes/groups: [group1], [group2], [group3], and [group4].
===Enneking (MSTS) Staging System===
*The Enneking surgical staging system (also known as the MSTS system) for benign [[Musculoskeletal system|musculoskeletal]] [[Tumor|tumors]] based on [[radiographic]] characteristics of the [[tumor]] host margin.<ref name="pmid20333492">{{cite journal| author=Jawad MU, Scully SP| title=In brief: classifications in brief: enneking classification: benign and malignant tumors of the musculoskeletal system. | journal=Clin Orthop Relat Res | year= 2010 | volume= 468 | issue= 7 | pages= 2000-2 | pmid=20333492 | doi=10.1007/s11999-010-1315-7 | pmc=2882012 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20333492  }} </ref>
*It is widely accepted and routinely used classification.


OR
{| style="border: 0px; font-size: 90%; margin: 3px; width: 1000px" align="center"
 
| valign="top" |
[Disease name] may be classified into [large number > 6] subtypes based on [classification method 1], [classification method 2], and [classification method 3].
|-
[Disease name] may be classified into several subtypes based on [classification method 1], [classification method 2], and [classification method 3].
! style="background: #4479BA; width: 200px;" | {{fontcolor|#FFF|Stages}}
 
! style="background: #4479BA; width: 300px;" | {{fontcolor|#FFF|Description}}
OR
|-
 
| style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;" |1
Based on the duration of symptoms, [disease name] may be classified as either acute or chronic.
| style="padding: 5px 5px; background: #F5F5F5;" | Latent: Well demarcated borders
 
|-
OR
| style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;" |2
 
| style="padding: 5px 5px; background: #F5F5F5;" | Active: Indistinct borders
If the staging system involves specific and characteristic findings and features:
|-
According to the [staging system + reference], there are [number] stages of [malignancy name] based on the [finding1], [finding2], and [finding3]. Each stage is assigned a [letter/number1] and a [letter/number2] that designate the [feature1] and [feature2].
| style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;" |3
 
| style="padding: 5px 5px; background: #F5F5F5;" | Aggressive: Indistinct borders
OR
|}
 
The staging of [malignancy name] is based on the [staging system].
 
OR
 
There is no established system for the staging of [malignancy name].


==Pathophysiology==
==Pathophysiology==
The exact pathogenesis of [disease name] is not fully understood.
*The exact [[pathogenesis]] of unicameral bone cyst is not fully understood.
 
*Various theories have been proposed concerning the [[pathogenesis]] of unicameral bone cyst:
OR
**Blockage in the [[Venous return|venous drainage]] is the most favored mechanism which occurs in a rapidly growing and remodeling portion of [[cancellous bone]].
 
**Increased internal pressure of involved bone as compared to normal pressure of [[bone marrow]].<ref>Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.</ref>
It is thought that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
**Lower partial pressure of [[oxygen]] of cyst fluid than [[arterial]] or [[venous]] [[blood]] suggesting a [[venous]] obstruction.<ref>Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.</ref>
 
**Increased levels of [[lysosomal]] [[enzymes]] in the cyst than [[serum]]. [[Enzymes]] include [[Prostaglandin|prostaglandins]], interleukin 1β, [[nitrate]] and [[Nitrite|nitrites]] levels, [[proteolytic]] [[enzymes]], [[Tumor necrosis factor|tumor necrosis factor ⍺]] and [[Interleukin|interleukins]] 1β and [[Interleukin 6|6]].<ref name="pmid10968539">{{cite journal| author=Komiya S, Inoue A| title=Development of a solitary bone cyst--a report of a case suggesting its pathogenesis. | journal=Arch Orthop Trauma Surg | year= 2000 | volume= 120 | issue= 7-8 | pages= 455-7 | pmid=10968539 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10968539  }} </ref>
OR
*Unicameral bone cyst typically occur in the [[metaphysis]] adjacent to the physis of the [[long bones]].
 
*The [[bones]] often involved are proximal [[femur]], distal [[tibia]], [[Ilium (bone)|ilium]], [[calcaneus]], and occasionally [[Metacarpus|metacarpals]], [[Phalanx bones|phalanges]], or distal [[radius]].
[Pathogen name] is usually transmitted via the [transmission route] route to the human host.
 
OR
 
Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
 
OR
 
 
[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].
 
OR


The progression to [disease name] usually involves the [molecular pathway].
===Genetics===
 
*Unicameral bone cyst may have association with [[genetic]] abnormalities on [[chromosome 4]], [[Chromosome 6|6]], [[Chromosome 8|8]], [[Chromosome 16|16]], [[Chromosome 21|21]], and both [[Chromosome 12|chromosomes 12]].
OR
*Translocation t (16; 20) (p11.2; q13) has been found in cases with unicameral bone cyst.
 
The pathophysiology of [disease/malignancy] depends on the histological subtype.


==Causes==
==Causes==
Disease name] may be caused by [cause1], [cause2], or [cause3].
There are no established causes for unicameral bone cyst.


OR
==Differentiating Unicameral Bone Cyst from Other Diseases==
 
Unicameral bone cyst must be differentiated from following bone disorders:
Common causes of [disease] include [cause1], [cause2], and [cause3].
{|
 
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Disease
OR
! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Bubbly lytic lesion on x-ray'''
 
! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Lakes of Blood on histology'''
The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Diagnosis
 
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Treatment is curretage and bone grafting
OR
|-
 
! align="center" style="background:#DCDCDC;" + |Unicameral bone cyst
The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click [[Pericarditis causes#Overview|here]].
| align="center" style="background:#F5F5F5;" + | +
 
| align="center" style="background:#F5F5F5;" + | -
==Differentiating ((Page name)) from Other Diseases==
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].
| align="center" style="background:#F5F5F5;" + | -
 
|-
OR
! align="center" style="background:#DCDCDC;" + |[[Aneurysmal bone cyst]]
 
| align="center" style="background:#F5F5F5;" + | +
[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].
| align="center" style="background:#F5F5F5;" + | +
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
| align="center" style="background:#F5F5F5;" + | +
|-
! align="center" style="background:#DCDCDC;" + |[[Non ossifying fibroma]]
| align="center" style="background:#F5F5F5;" + | +
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
| align="center" style="background:#F5F5F5;" + | -
|-
! align="center" style="background:#DCDCDC;" + |[[Giant cell tumor of bone|Giant cell tumor]]
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[Biopsy]]
| align="center" style="background:#F5F5F5;" + | +
|-
! align="center" style="background:#DCDCDC;" + |[[Chondroblastoma]]
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + |[[Biopsy]]
| align="center" style="background:#F5F5F5;" + | +
|-
! align="center" style="background:#DCDCDC;" + |[[Chondromyxoid Fibroma]]
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
| align="center" style="background:#F5F5F5;" + | +
|-
! align="center" style="background:#DCDCDC;" + |[[Osteoblastoma]]
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
| align="center" style="background:#F5F5F5;" + | +
|-
! align="center" style="background:#DCDCDC;" + |Telangiectatic [[osteosarcoma]]
| align="center" style="background:#F5F5F5;" + | -
| align="center" style="background:#F5F5F5;" + | +
| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
| align="center" style="background:#F5F5F5;" + | -
|}


==Epidemiology and Demographics==
==Epidemiology and Demographics==
The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
*Unicameral bone cyst constitute approximately 3% of all [[bone tumors]].
 
*Adolescents and children are most affected by unicameral bone cyst.<ref name="pmid24788445">{{cite journal| author=Pretell-Mazzini J, Murphy RF, Kushare I, Dormans JP| title=Unicameral bone cysts: general characteristics and management controversies. | journal=J Am Acad Orthop Surg | year= 2014 | volume= 22 | issue= 5 | pages= 295-303 | pmid=24788445 | doi=10.5435/JAAOS-22-05-295 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24788445  }} </ref>
OR
*The age distribution of unicameral bone cyst is between 5-15 years.<ref name="pmid11856945">{{cite journal| author=Biermann JS| title=Common benign lesions of bone in children and adolescents. | journal=J Pediatr Orthop | year= 2002 | volume= 22 | issue= 2 | pages= 268-73 | pmid=11856945 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11856945  }} </ref>
 
*The mean age of the patients with unicameral bone cyst is 9 years.
In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
*Men are more commonly affected than women, with a 2:1 ratio.<ref name="pmid4874360">{{cite journal| author=Boseker EH, Bickel WH, Dahlin DC| title=A clinicopathologic study of simple unicameral bone cysts. | journal=Surg Gynecol Obstet | year= 1968 | volume= 127 | issue= 3 | pages= 550-60 | pmid=4874360 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4874360  }} </ref>
 
*There is no racial predilection to unicameral bone cyst.
OR
 
In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
 
 
 
Patients of all age groups may develop [disease name].
 
OR
 
The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
 
OR
 
[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
 
OR
 
[Chronic disease name] is usually first diagnosed among [age group].
 
OR
 
[Acute disease name] commonly affects [age group].
 
 
 
There is no racial predilection to [disease name].
 
OR
 
[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
 
 
 
[Disease name] affects men and women equally.
 
OR
 
[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
 
 
 
The majority of [disease name] cases are reported in [geographical region].
 
OR
 
[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].


==Risk Factors==
==Risk Factors==
There are no established risk factors for [disease name].
There are no established [[risk factors]] for unicameral bone cyst.
 
OR
 
The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
 
OR
 
Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
 
OR
 
Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.


==Screening==
==Screening==
There is insufficient evidence to recommend routine screening for [disease/malignancy].
There is insufficient evidence to recommend routine [[Screening (medicine)|screening]] for unicameral bone cyst.
 
OR
 
According to the [guideline name], screening for [disease name] is not recommended.
 
OR
 
According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].


==Natural History, Complications, and Prognosis==
==Natural History, Complications, and Prognosis==
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
*Common [[complications]] of unicameral bone cyst (UBC) include:
 
**Pathological [[Bone fracture|fracture]]
OR
**Premature [[Epiphyseal plate|epiphyseal]] closure
 
***[[Limb-length discrepancy]]
Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
***[[Angular deformity]]
 
**[[Malignant transformation]]
OR
*[[Prognosis]] is generally excellent for Unicameral bone cyst.
 
**As a patient approaches [[skeletal]] maturity, a unicameral bone cyst will often decrease in size and may heal after growth is complete.
Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
**[[Fracture]] healing usually does not lead to cyst resolution.
**It requires close follow up while in active phase due to recurrence and risk of [[fracture]] or growth arrest.


==Diagnosis==
==Diagnosis==
===Diagnostic Study of Choice===
===Diagnostic Study of Choice===
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
*[[Biopsy]] is the diagnostic study of choice for the [[diagnosis]] of unicameral bone cyst.
 
*[[Biopsy]] findings include:
OR
**[[Cyst]] are lined with thin [[fibrous]] lining containing [[fibrous tissue]], [[giant cells]], and [[hemosiderin]] pigment.
 
**[[Inflammatory cells]] such as [[Lymphocyte|lymphocytes]] may be found in small numbers.
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
**Uniform amount of [[spindle cells]] without nuclear atypia.
 
OR
 
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
There are no established criteria for the diagnosis of [disease name].


===History and Symptoms===
===History and Symptoms===
The majority of patients with [disease name] are asymptomatic.
*The majority of patients with unicameral bone cyst have a positive history of:
 
**[[Pain]]
OR
**[[Swelling]]
 
**Pathological [[Bone fracture|fracture]]
The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].
**Neurologic conditions occur often due to compression of either the [[spinal cord]] or [[nerve roots]], and leading to [[paralysis]] and spinal [[stiffness]]


===Physical Examination===
===Physical Examination===
Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].
*Common [[physical examination]] findings of unicameral bone cyst include:
 
**[[Deformity]]
OR
**Decreased [[range of motion]], [[weakness]], or [[stiffness]]
 
**[[Torticollis]]
Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
**Occasionally, [[bruit]] over the affected area
 
**Warmth over the affected area
OR
{| align="right"
 
|
The presence of [finding(s)] on physical examination is diagnostic of [disease name].
[[File:Xray UBC.gif|300px|thumb|X-ray showing unicameral bone cyst of left proximal femur.[https://radiopaedia.org/cases/unicameral-bone-cyst-9?lang=us Source: Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 10361]]]
 
|}
OR
 
The presence of [finding(s)] on physical examination is highly suggestive of [disease name].
 
===Laboratory Findings===
===Laboratory Findings===
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
There are no diagnostic laboratory findings associated with unicameral bone cyst.
 
OR
 
Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
 
OR
 
[Test] is usually normal among patients with [disease name].
 
OR
 
Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
 
OR
 
There are no diagnostic laboratory findings associated with [disease name].


===Electrocardiogram===
===Electrocardiogram===
There are no ECG findings associated with [disease name].
There are no [[The electrocardiogram|ECG findings]] associated with unicameral bone cyst.
 
OR
 
An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].


===X-ray===
===X-ray===
There are no x-ray findings associated with [disease name].
*Findings on an [[x-ray]] suggestive of unicameral bone cyst include include:<ref name="pmid5771835">{{cite journal| author=Reynolds J| title=The "fallen fragment sign" in the diagnosis of unicameral bone cysts. | journal=Radiology | year= 1969 | volume= 92 | issue= 5 | pages= 949-53 passim | pmid=5771835 | doi=10.1148/92.5.949 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=5771835  }} </ref><ref name="pmid7226646">{{cite journal| author=McGlynn FJ, Mickelson MR, El-Khoury GY| title=The fallen fragment sign in unicameral bone cyst. | journal=Clin Orthop Relat Res | year= 1981 | volume=  | issue= 156 | pages= 157-9 | pmid=7226646 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7226646  }} </ref>
 
**Central, [[lytic]], well-demarcated [[metaphyseal]] lesion.
OR
**[[Cystic]] expansion with symmetric thinning of cortices.
 
**"Fallen leaf" is a pathognomic sign seen in pathologic [[fracture]] with fallen cortical fragment in base of empty cyst.  
An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
**Trabeculated appearance after multiple [[fractures]].
 
{| align="right"
OR
|
 
[[File:CT UBC.gif|300px|thumb|CT scan showing unicameral bone cyst of left proximal femur.[https://radiopaedia.org/cases/unicameral-bone-cyst-9?lang=us Source: Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 10361]]]
There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
|}


===Echocardiography or Ultrasound===
===Echocardiography or Ultrasound===
There are no echocardiography/ultrasound  findings associated with [disease name].
There are no [[echocardiography]]/[[ultrasound]] findings associated with unicameral bone cyst.
 
OR
 
Echocardiography/ultrasound  may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
 
OR
 
There are no echocardiography/ultrasound  findings associated with [disease name]. However, an echocardiography/ultrasound  may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].


===CT scan===
===CT scan===
There are no CT scan findings associated with [disease name].
*[[CT scan]] confirms the [[x-ray]] findings.
 
*In addition, [[CT-scans|CT]] demonstrates internal [[septation]] such as calcified rim, giving an eggshell appearance, which may be completely or partially intact.
OR
*Free fluid levels can also be seen.
 
[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
 
OR
 
There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].


===MRI===
===MRI===
There are no MRI findings associated with [disease name].
[[MRI]] findings of unicameral bone cyst include:<ref name="pmid9727265">{{cite journal| author=Maas EJ, Craig JG, Swisher PK, Amin MB, Marcus N| title=Fluid-fluid levels in a simple bone cyst on magnetic resonance imaging. | journal=Australas Radiol | year= 1998 | volume= 42 | issue= 3 | pages= 267-70 | pmid=9727265 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9727265  }} </ref><ref name="pmid10993540">{{cite journal| author=Margau R, Babyn P, Cole W, Smith C, Lee F| title=MR imaging of simple bone cysts in children: not so simple. | journal=Pediatr Radiol | year= 2000 | volume= 30 | issue= 8 | pages= 551-7 | pmid=10993540 | doi=10.1007/s002470000258 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10993540  }} </ref><ref name="pmid10627734">{{cite journal| author=Sullivan RJ, Meyer JS, Dormans JP, Davidson RS| title=Diagnosing aneurysmal and unicameral bone cysts with magnetic resonance imaging. | journal=Clin Orthop Relat Res | year= 1999 | volume=  | issue= 366 | pages= 186-90 | pmid=10627734 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10627734  }} </ref>
 
*Very dark on T1
OR
*Very bright on T2
 
*[[Gadolinium]] shows classic rim enhancement of a cystic lesion
[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
{| align="right"
 
|
OR
[[File:MRI UBC.gif|300px|thumb|MRI scan showing unicameral bone cyst of left proximal humerus.[https://radiopaedia.org/cases/unicameral-bone-cyst-10?lang=us Source: Case courtesy of Dr Yasser Asiri, Radiopaedia.org, rID: 65130]]]
 
|}
There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].


===Other Imaging Findings===
===Other Imaging Findings===
There are no other imaging findings associated with [disease name].


OR
===Bone Scan===
 
*Increased uptake is observed around the lesion of unicameral bone cyst.
[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
*Findings often demonstrate a halo effect of increased [[radionuclide]] uptake surrounding an area of little uptake.


===Other Diagnostic Studies===
===Other Diagnostic Studies===
There are no other diagnostic studies associated with [disease name].


OR
===Angiography===
*[[Angiography]] demonstrates a hypervascular area around the unicameral bone cyst.
*An intense diffuse area of persistent contrast accumulation may be visualized without main afferent or efferent [[Blood vessel|vessels]] observed.


[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
==Treatment==
The mainstay of therapy for unicameral bone cyst is [[surgery]].


OR
Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].
==Treatment==
===Medical Therapy===
===Medical Therapy===
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
OR
Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
OR
The majority of cases of [disease name] are self-limited and require only supportive care.
OR
[Disease name] is a medical emergency and requires prompt treatment.
OR
The mainstay of treatment for [disease name] is [therapy].
OR
 
The optimal therapy for [malignancy name] depends on the stage at diagnosis.
OR
[Therapy] is recommended among all patients who develop [disease name].
OR
Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
OR


Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
===Immobilization===   


OR
'''Indications'''
*Proximal [[humerus]] lesions with pathologic [[Bone fracture|fracture]]
*Inaccessible lesions


Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
===Aspiration and Methylprednisolone Acetate Injection===


OR
'''Indications'''
*Active [[Cyst|cysts]] which are communicating with physis.


Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
'''Technique'''
*Usually requires several injections, especially in very young children.
*[[Bone marrow]] injections have recently been reported to be effective.  


===Surgery===
===Surgery===
Surgical intervention is not recommended for the management of [disease name].
[[Surgery]] is the mainstay of treatment for unicameral bone cyst.


OR
===Curettage and bone grafting with internal fixation===


Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]
'''Indications'''
*[[Symptomatic]] latent [[Cyst|cysts]] that have not responded to [[steroid]] injections.
*Latent [[Cyst|cysts]] located in areas such as proximal [[femur]] where structural integrity is a concern and at risk for [[fracture]] and [[osteonecrosis]].
*Lesions with a pathologic [[Bone fracture|fracture]] that have a higher rate of re-[[Bone fracture|fracture]] and malunion when treated nonoperatively.


OR
'''Contraindications'''
*Active lesions which are in communication with physis, which may result in growth arrest.


The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].
===Treatment Response Evaluation===
 
Neer rating system for the purposes of evaluating treatment response are as follows:<ref name="pmid15580740">{{cite journal| author=Neer CS, Francis KC, Marcove RC, Terz J, Carbonara PN| title=Treatment of unicameral bone cyst. A follow-up study of one hundred seventy-five cases. | journal=J Bone Joint Surg Am | year= 1966 | volume= 48 | issue= 4 | pages= 731-45 | pmid=15580740 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15580740  }} </ref>
OR
*Excellent – Complete obliteration of the [[cyst]].
 
*Residual defect – One or more static [[cyst]] like areas with good reestablishment of [[bone]] strength.
The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
*Reoperation – Subsequent operation required because of recurrence.
 
OR
 
Surgery is the mainstay of treatment for [disease or malignancy].


===Primary Prevention===
===Primary Prevention===
There are no established measures for the primary prevention of [disease name].
There are no established measures for the [[primary prevention]] of unicameral bone cyst.
 
OR
 
There are no available vaccines against [disease name].
 
OR
 
Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
 
OR
 
[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].


===Secondary Prevention===
===Secondary Prevention===
There are no established measures for the secondary prevention of [disease name].
There are no established measures for the [[secondary prevention]] of unicameral bone cyst.
 
OR
 
Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].


==References==
==References==
{{reflist|2}}
{{reflist|2}}
[[Category:Orthopedics]]
[[Category:Oncology]]
[[Category:Up-To-Date]]


{{WikiDoc Help Menu}}
{{WikiDoc Help Menu}}
{{WikiDoc Sources}}
{{WikiDoc Sources}}

Latest revision as of 17:40, 3 April 2019

WikiDoc Resources for Unicameral bone cyst

Articles

Most recent articles on Unicameral bone cyst

Most cited articles on Unicameral bone cyst

Review articles on Unicameral bone cyst

Articles on Unicameral bone cyst in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Unicameral bone cyst

Images of Unicameral bone cyst

Photos of Unicameral bone cyst

Podcasts & MP3s on Unicameral bone cyst

Videos on Unicameral bone cyst

Evidence Based Medicine

Cochrane Collaboration on Unicameral bone cyst

Bandolier on Unicameral bone cyst

TRIP on Unicameral bone cyst

Clinical Trials

Ongoing Trials on Unicameral bone cyst at Clinical Trials.gov

Trial results on Unicameral bone cyst

Clinical Trials on Unicameral bone cyst at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Unicameral bone cyst

NICE Guidance on Unicameral bone cyst

NHS PRODIGY Guidance

FDA on Unicameral bone cyst

CDC on Unicameral bone cyst

Books

Books on Unicameral bone cyst

News

Unicameral bone cyst in the news

Be alerted to news on Unicameral bone cyst

News trends on Unicameral bone cyst

Commentary

Blogs on Unicameral bone cyst

Definitions

Definitions of Unicameral bone cyst

Patient Resources / Community

Patient resources on Unicameral bone cyst

Discussion groups on Unicameral bone cyst

Patient Handouts on Unicameral bone cyst

Directions to Hospitals Treating Unicameral bone cyst

Risk calculators and risk factors for Unicameral bone cyst

Healthcare Provider Resources

Symptoms of Unicameral bone cyst

Causes & Risk Factors for Unicameral bone cyst

Diagnostic studies for Unicameral bone cyst

Treatment of Unicameral bone cyst

Continuing Medical Education (CME)

CME Programs on Unicameral bone cyst

International

Unicameral bone cyst en Espanol

Unicameral bone cyst en Francais

Business

Unicameral bone cyst in the Marketplace

Patents on Unicameral bone cyst

Experimental / Informatics

List of terms related to Unicameral bone cyst

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rohan A. Bhimani, M.B.B.S., D.N.B., M.Ch.[2]

Synonyms and keywords: Simple bone cyst; Traumatic bone cyst, UBC

Overview

Unicameral bone cyst (UBC) constitute approximately 3% of all bone tumors. Adolescents and children are most affected by unicameral bone cyst. The age distribution of unicameral bone cyst is between 5-15 years. Men are more commonly affected compared to women, with a 2:1 ratio. In 1942, Jaffe and Lichenstein later recognized it as a distinct entity. The exact pathogenesis of unicameral bone cyst is not fully understood. Unicameral bone cyst may have association with genetic abnormalities on chromosome 4, 6, 8, 16, 21, and both chromosomes 12. The bones often involved are proximal femur, distal tibia, ilium, calcaneus, and occasionally metacarpals, phalanges, or distal radius. Unicameral bone cyst typically occur in the metaphysis adjacent to the physis of the long bones. The hallmark of UBC is pain, swelling and pathological fracture. The mainstay of treatment for UBC is surgery in form of curettage and bone grafting.

Historical Perspective

  • In mediveal times, Lagier et al identified a unicameral bone cyst in the femur from the remains of a child.[1]
  • In 1891, Virchow reported it as “cystic structures” that resulted due to anomalies in the local circulation.[2]
  • In 1942, Jaffe and Lichenstein later recognized it as a distinct entity.[3]

Classification

Unicameral bone cyst can be classified based on imaging findings.

Enneking (MSTS) Staging System

  • The Enneking surgical staging system (also known as the MSTS system) for benign musculoskeletal tumors based on radiographic characteristics of the tumor host margin.[4]
  • It is widely accepted and routinely used classification.
Stages Description
1 Latent: Well demarcated borders
2 Active: Indistinct borders
3 Aggressive: Indistinct borders

Pathophysiology

Genetics

  • Unicameral bone cyst may have association with genetic abnormalities on chromosome 4, 6, 8, 16, 21, and both chromosomes 12.
  • Translocation t (16; 20) (p11.2; q13) has been found in cases with unicameral bone cyst.

Causes

There are no established causes for unicameral bone cyst.

Differentiating Unicameral Bone Cyst from Other Diseases

Unicameral bone cyst must be differentiated from following bone disorders:

Disease Bubbly lytic lesion on x-ray Lakes of Blood on histology Diagnosis Treatment is curretage and bone grafting
Unicameral bone cyst + - Radiology and biopsy -
Aneurysmal bone cyst + + Radiology and biopsy +
Non ossifying fibroma + - Radiology and biopsy -
Giant cell tumor - - Radiology and Biopsy +
Chondroblastoma - - Biopsy +
Chondromyxoid Fibroma - - Radiology and biopsy +
Osteoblastoma - - Radiology and biopsy +
Telangiectatic osteosarcoma - + Radiology and biopsy -

Epidemiology and Demographics

  • Unicameral bone cyst constitute approximately 3% of all bone tumors.
  • Adolescents and children are most affected by unicameral bone cyst.[8]
  • The age distribution of unicameral bone cyst is between 5-15 years.[9]
  • The mean age of the patients with unicameral bone cyst is 9 years.
  • Men are more commonly affected than women, with a 2:1 ratio.[10]
  • There is no racial predilection to unicameral bone cyst.

Risk Factors

There are no established risk factors for unicameral bone cyst.

Screening

There is insufficient evidence to recommend routine screening for unicameral bone cyst.

Natural History, Complications, and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

X-ray showing unicameral bone cyst of left proximal femur.Source: Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 10361

Laboratory Findings

There are no diagnostic laboratory findings associated with unicameral bone cyst.

Electrocardiogram

There are no ECG findings associated with unicameral bone cyst.

X-ray

  • Findings on an x-ray suggestive of unicameral bone cyst include include:[11][12]
    • Central, lytic, well-demarcated metaphyseal lesion.
    • Cystic expansion with symmetric thinning of cortices.
    • "Fallen leaf" is a pathognomic sign seen in pathologic fracture with fallen cortical fragment in base of empty cyst.
    • Trabeculated appearance after multiple fractures.
CT scan showing unicameral bone cyst of left proximal femur.Source: Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 10361

Echocardiography or Ultrasound

There are no echocardiography/ultrasound findings associated with unicameral bone cyst.

CT scan

  • CT scan confirms the x-ray findings.
  • In addition, CT demonstrates internal septation such as calcified rim, giving an eggshell appearance, which may be completely or partially intact.
  • Free fluid levels can also be seen.

MRI

MRI findings of unicameral bone cyst include:[13][14][15]

  • Very dark on T1
  • Very bright on T2
  • Gadolinium shows classic rim enhancement of a cystic lesion
MRI scan showing unicameral bone cyst of left proximal humerus.Source: Case courtesy of Dr Yasser Asiri, Radiopaedia.org, rID: 65130

Other Imaging Findings

Bone Scan

  • Increased uptake is observed around the lesion of unicameral bone cyst.
  • Findings often demonstrate a halo effect of increased radionuclide uptake surrounding an area of little uptake.

Other Diagnostic Studies

Angiography

  • Angiography demonstrates a hypervascular area around the unicameral bone cyst.
  • An intense diffuse area of persistent contrast accumulation may be visualized without main afferent or efferent vessels observed.

Treatment

The mainstay of therapy for unicameral bone cyst is surgery.

Medical Therapy

Immobilization

Indications

Aspiration and Methylprednisolone Acetate Injection

Indications

  • Active cysts which are communicating with physis.

Technique

  • Usually requires several injections, especially in very young children.
  • Bone marrow injections have recently been reported to be effective.

Surgery

Surgery is the mainstay of treatment for unicameral bone cyst.

Curettage and bone grafting with internal fixation

Indications

Contraindications

  • Active lesions which are in communication with physis, which may result in growth arrest.

Treatment Response Evaluation

Neer rating system for the purposes of evaluating treatment response are as follows:[16]

  • Excellent – Complete obliteration of the cyst.
  • Residual defect – One or more static cyst like areas with good reestablishment of bone strength.
  • Reoperation – Subsequent operation required because of recurrence.

Primary Prevention

There are no established measures for the primary prevention of unicameral bone cyst.

Secondary Prevention

There are no established measures for the secondary prevention of unicameral bone cyst.

References

  1. Lagier R, Kramar C, Baud CA (1987). "Femoral unicameral bone cyst in a medieval child. Radiological and pathological study". Pediatr Radiol. 17 (6): 498–500. PMID 3317251.
  2. Wilkins RM (2000). "Unicameral bone cysts". J Am Acad Orthop Surg. 8 (4): 217–24. PMID 10951110.
  3. Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg. 1942. 44:1004-25.
  4. Jawad MU, Scully SP (2010). "In brief: classifications in brief: enneking classification: benign and malignant tumors of the musculoskeletal system". Clin Orthop Relat Res. 468 (7): 2000–2. doi:10.1007/s11999-010-1315-7. PMC 2882012. PMID 20333492.
  5. Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.
  6. Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.
  7. Komiya S, Inoue A (2000). "Development of a solitary bone cyst--a report of a case suggesting its pathogenesis". Arch Orthop Trauma Surg. 120 (7–8): 455–7. PMID 10968539.
  8. Pretell-Mazzini J, Murphy RF, Kushare I, Dormans JP (2014). "Unicameral bone cysts: general characteristics and management controversies". J Am Acad Orthop Surg. 22 (5): 295–303. doi:10.5435/JAAOS-22-05-295. PMID 24788445.
  9. Biermann JS (2002). "Common benign lesions of bone in children and adolescents". J Pediatr Orthop. 22 (2): 268–73. PMID 11856945.
  10. Boseker EH, Bickel WH, Dahlin DC (1968). "A clinicopathologic study of simple unicameral bone cysts". Surg Gynecol Obstet. 127 (3): 550–60. PMID 4874360.
  11. Reynolds J (1969). "The "fallen fragment sign" in the diagnosis of unicameral bone cysts". Radiology. 92 (5): 949-53 passim. doi:10.1148/92.5.949. PMID 5771835.
  12. McGlynn FJ, Mickelson MR, El-Khoury GY (1981). "The fallen fragment sign in unicameral bone cyst". Clin Orthop Relat Res (156): 157–9. PMID 7226646.
  13. Maas EJ, Craig JG, Swisher PK, Amin MB, Marcus N (1998). "Fluid-fluid levels in a simple bone cyst on magnetic resonance imaging". Australas Radiol. 42 (3): 267–70. PMID 9727265.
  14. Margau R, Babyn P, Cole W, Smith C, Lee F (2000). "MR imaging of simple bone cysts in children: not so simple". Pediatr Radiol. 30 (8): 551–7. doi:10.1007/s002470000258. PMID 10993540.
  15. Sullivan RJ, Meyer JS, Dormans JP, Davidson RS (1999). dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10627734 "Diagnosing aneurysmal and unicameral bone cysts with magnetic resonance imaging" Check |url= value (help). Clin Orthop Relat Res (366): 186–90. PMID 10627734.
  16. Neer CS, Francis KC, Marcove RC, Terz J, Carbonara PN (1966). "Treatment of unicameral bone cyst. A follow-up study of one hundred seventy-five cases". J Bone Joint Surg Am. 48 (4): 731–45. PMID 15580740.


Template:WikiDoc Sources