Thymoma pathophysiology

Revision as of 20:45, 20 February 2014 by Amr Marawan (talk | contribs)
Jump to navigation Jump to search

Thymoma Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Thymoma from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

Echocardiography and Ultrasound

CT scan

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Thymoma pathophysiology On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Thymoma pathophysiology

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Thymoma pathophysiology

CDC on Thymoma pathophysiology

Thymoma pathophysiology in the news

Blogs on Thymoma pathophysiology

Directions to Hospitals Treating Thymoma

Risk calculators and risk factors for Thymoma pathophysiology

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

Please help WikiDoc by adding more content here. It's easy! Click here to learn about editing.

Overview

Pathophysiology

Thymoma originates from the epithelial cell population in the thymus. Many subtypes are recognized, some of which have a better- or worse-than-general prognosis.[1]

Pathologic Classification

Thymic epithelial tumors can be divided according to the degree of differentiation into:

  • Type A. Medullar thymoma: population of neoplastic thymic epithelial cells having a spindle/oval shape, lacking nuclear atypia and accompanied by few or no non-neopl astic lymphocytes.
  • Type B. Cortical thymoma: round and polygonal tumour cells.According to the infiltration of lymphocytes and cellular atypia are subclassified into:B1(large lymphocytic infiltrate with epithelial cells, practically indisting uishable from normal thymic cortex tumour that resembles the normal functional thymus), B2 (less lymphocytic infiltrate, the neoplastic epithelial component appears as scattered plump cells with vesicular nuclei and distinct nucleoli, perivascul ar spaces are common and sometimes very prominent with a perivascular arrangement of tumour cells), B3 (epithelial cells having a round or polygonal shape and exhibiting no or mild atypia, admixed with a minor component of lymphocytes, sheet-lik e growth of the neoplastic epithelial cells).
  • Type AB. Combined areas of A and B characteristics (foci having the features of type A thymoma are admixed with foci rich in lymphocytes).
  • Type C. Thymic carcinoma: clear-cut cytologic atypia and a set of cytoarchitectural features no longer specific to the thymus but rather analogous to those seen in carcinomas of other organs, lack immature lymphocytes.

According to different published series, it is estimated that sub-types B2 and AB are the most common (20–35%) while A and B1 subtypes have a much lower incidence (5–10%).[2]

Associated Disorders

A third of the patients who have a thymoma detected because they have an associated autoimmune disorder. The most common condition in this group is myasthenia gravis (of which 25-50% are associated with a thymoma); patients with myasthenia are routinely screened for thymoma. Other associated autoimmune conditions are pure red cell aplasia and Good's syndrome (thymoma with combined immunodeficiency and hypoimmunoglobulinemia G). Rare associations that have been reported are: acute pericarditis, Addison's disease, agranulocytosis, alopecia areata, ulcerative colitis, Cushing's disease, hemolytic anemia, limbic encephalopathy, myocarditis, nephrotic syndrome, panhypopituitarism, pernicious anemia, polymyositis, rheumatoid arthritis, sarcoidosis, scleroderma, sensorimotor radiculopathy, stiff person syndrome, systemic lupus erythematosus and thyroiditis.[1]

References

  1. 1.0 1.1 Thomas CR, Wright CD, Loehrer PJ (1999). "Thymoma: state of the art". Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. 17 (7): 2280–9. PMID 10561285. Retrieved 2012-01-18. Unknown parameter |month= ignored (help)
  2. "WHO histologic classification is a prognosti... [Ann Thorac Surg. 2004] - PubMed - NCBI".


Template:WikiDoc Sources