Protoplasmic astrocytoma: Difference between revisions

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==MRI==
==MRI==
*The possibility that a primary cerebral neoplasm represents a protoplasmic astrocytoma should be considered in a patient with a large frontal or temporal tumor that has a very high signal on T2 with a large proportion of the tumor showing substantial T2 FLAIR suppression.
*The possibility that a primary cerebral neoplasm represents a protoplasmic astrocytoma should be considered in a patient with a large frontal or temporal tumor that has a very high signal on T2 with a large proportion of the tumor showing substantial T2 FLAIR suppression.<ref name="pmid20644924">{{cite journal| author=Tay KL, Tsui A, Phal PM, Drummond KJ, Tress BM| title=MR imaging characteristics of protoplasmic astrocytomas. | journal=Neuroradiology | year= 2011 | volume= 53 | issue= 6 | pages= 405-11 | pmid=20644924 | doi=10.1007/s00234-010-0741-2 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20644924  }} </ref>
*Brain MRI is helpful in the diagnosis of protoplasmic astrocytoma. On MRI, protoplasmic astrocytoma is characterized by:<ref name=radiologicalfeaturspa1>Radiological features of protoplasmic astrocytoma. Dr Bruno Di Muzio and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/protoplasmic-astrocytoma. Accessed on January 8, 2016</ref><ref name=radiographicfeaturesga1>Radiographic features of low grade infiltrative astrocytoma. Dr Ahmed Abd Rabou and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/low-grade-infiltrative-astrocytoma. Accessed on January 8, 2016</ref>
*Brain MRI is helpful in the diagnosis of protoplasmic astrocytoma. On MRI, protoplasmic astrocytoma is characterized by:<ref name=radiologicalfeaturspa1>Radiological features of protoplasmic astrocytoma. Dr Bruno Di Muzio and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/protoplasmic-astrocytoma. Accessed on January 8, 2016</ref><ref name=radiographicfeaturesga1>Radiographic features of low grade infiltrative astrocytoma. Dr Ahmed Abd Rabou and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/low-grade-infiltrative-astrocytoma. Accessed on January 8, 2016</ref>



Revision as of 19:01, 15 July 2019

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2]

Synonyms and keywords: Protoplasmic astrocytomas; Diffuse astrocytoma; Low grade astrocytoma

Overview

Protoplasmic astrocytoma is a rare variant of diffuse low grade astrocytoma with characteristic histological and imaging features. It has been suggested that protoplasmic astrocytoma represents a variant of dysembryoplastic neuroepithelial tumors (DNET), as they share histologic and imaging features. Currently, protoplasmic astrocytoma is classified as a subtype of diffuse low-grade astrocytoma.

Pathophysiology

Gross Pathology

Microscopic Pathology

  • On microscopic histopathological analysis, protoplasmic astrocytoma is characterized by:
  • Protoplasmic astrocytoma is a slow growing tumor with an indolent course.

Complications

  • Common complication of protoplasmic astrocytoma include:[1]

History and Symptoms

History

  • When evaluating a patient for protoplasmic astrocytoma, you should take a detailed history of the presenting symptom (onset, duration, and progression), other associated symptoms, and a thorough family and past medical history review.

Symptoms

  • Symptoms of protoplasmic astrocytoma include:[1]

CT

  • Head CT scan is helpful in the diagnosis of protoplasmic astrocytoma. On CT scan, protoplasmic astrocytoma is characterized by:[2]
  • Hypodense mass
  • Positive mass effect
  • No enhancement
  • Cystic or fluid attenuation, due to the aforementioned prominent mucinous microcystic component

MRI

  • The possibility that a primary cerebral neoplasm represents a protoplasmic astrocytoma should be considered in a patient with a large frontal or temporal tumor that has a very high signal on T2 with a large proportion of the tumor showing substantial T2 FLAIR suppression.[3]
  • Brain MRI is helpful in the diagnosis of protoplasmic astrocytoma. On MRI, protoplasmic astrocytoma is characterized by:[2][4]
MRI component Findings

T1

  • Hypointense compared to white matter

T2

  • Hyperintense compared to white matter

Fluid-attenuated inversion recovery (FLAIR)

  • Large areas of T2 hyperintensity suppress on FLAIR
  • These are not macrocystic, but rather represent the areas with abundant microcystic change

T1 with contrast

  • Little or no enhancement

Diffusion weighted imaging (DWI)

  • No restricted diffusion

Other Imaging Findings

Magnetic Resonance Spectroscopy

Magnetic Resonance Perfusion

  • MR perfusion may be helpful in the diagnosis of protoplasmic astrocytoma, which demonstrates no elevation of relative cerebral blood volume (rCBV).[2]

Electroencephalogram

  • Electroencephalogram (EEG) is performed in cases of protoplasmic astrocytoma to record the continuous electrical activity of the brain and locate the seizure activity.[5]

Biopsy

  • Biopsy of the protoplasmic astrocytoma tumor, taken through a needle during a simple surgical procedure, helps to confirm the diagnosis.[6]

Treatment

  • The treatment of protoplasmic astrocytoma depends on the clinical presentation, tumor size, and location.[6]
  • Surgery: The predominant therapy for protoplasmic astrocytoma is surgical resection.[6]
  • Radiotherapy: Radiotherapy may be used in protoplasmic astrocytoma post-operatively or at the time of recurrence or progression.[7]
  • Chemotherapy: Chemotherapy may have a role in recurrent and de-differentiated tumors.[7]


 
 
 
 
 
 
 
 
 
 
 
 
Treatment of protoplasmic astrocytoma
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Surgery
 
 
 
Radiotherapy
 
 
 
Chemotherapy
 
 
 
 
 
 
 
 
 
 
 
 
 

References

  1. 1.0 1.1 Clinical presentation of protoplasmic astrocytoma. Dr Bruno Di Muzio and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/protoplasmic-astrocytoma. Accessed on January 8, 2016
  2. 2.0 2.1 2.2 2.3 Radiological features of protoplasmic astrocytoma. Dr Bruno Di Muzio and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/protoplasmic-astrocytoma. Accessed on January 8, 2016
  3. Tay KL, Tsui A, Phal PM, Drummond KJ, Tress BM (2011). "MR imaging characteristics of protoplasmic astrocytomas". Neuroradiology. 53 (6): 405–11. doi:10.1007/s00234-010-0741-2. PMID 20644924.
  4. Radiographic features of low grade infiltrative astrocytoma. Dr Ahmed Abd Rabou and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/low-grade-infiltrative-astrocytoma. Accessed on January 8, 2016
  5. Radiographic features of fibrillary astrocytoma. Dr Henry Knipe and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/fibrillary-astrocytoma. Accessed on January 4, 2016
  6. 6.0 6.1 6.2 Treatment and prognosis of protoplasmic astrocytoma. Dr Bruno Di Muzio and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/protoplasmic-astrocytoma. Accessed on January 8, 2016
  7. 7.0 7.1 Treatment and prognosis of low grade infiltrative astrocytoma. Dr Ahmed Abd Rabou and A.Prof Frank Gaillard et al. Radiopaedia 2016. http://radiopaedia.org/articles/low-grade-infiltrative-astrocytoma. Accessed on January 8, 2016

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