Thymoma pathophysiology
|
Thymoma Microchapters |
|
Diagnosis |
|---|
|
Case Studies |
|
Thymoma pathophysiology On the Web |
|
American Roentgen Ray Society Images of Thymoma pathophysiology |
|
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] Ahmad Al Maradni, M.D. [3]
Overview
- On gross pathology, a well circumscribed mass that is locally invasive is a characteristic finding of thymoma.
- On microscopic histopathological analysis, round cells, with ample vacuolated cytoplasms, and fat droplets are characteristic findings of thymoma.
Pathophysiology
Physiology
- Thymus is the site of maturation of T cells.
- This makes thymus the primary center of adaptive immunity.
Pathogenesis
- The exact pathogenesis of the primary tumor development is not well understood.
- Primary tumors of thymus are relatively rare.
- Thymoma is the most common type of primary tumor of thymus.
- Thymoma is histologically comprised of abnormally conditioned T cells.
- The mingling of these abnormal T cells into the circulation is believed to be involved in the associated autoimmune disorders.[1][2]
Genetics
Genetic alterations reported for the different WHO histological thymomasubtypes[3]
| WHO Type | Chromosomal Gains | Chromosomal Losses |
| Type A | none | -6p |
| Type AB | none | -5q21-22,-6q,-12p,-16q |
| Type B3 | +1q | -6,-13q |
Associated Conditions
Approximately 30% of patients have their thymomas discovered because they have an associated autoimmune disorder. These disorders include:[4]
| Type | Diseases |
| Neuromuscular Diseases | Myasthenia gravis, neuromyotonia, rippling muscle disease, polymyositis/dermatomyositis, encephalitis (limbic, cortical and brain stem), intestinal pseudoobstruction |
| Haematologic Autoimmune Diseases | Anemia: pure red cell aplasia, pernicious anemia, hemolytic anemia, aplastic anemia. Other isolated cytopenia: eosinophils,basophils, neutrophils, immunodeficiencies: hypogammaglobulinaemia +/- T-cell deficiencies (Good syndrome) |
| Dermatologies Diseases | Pemphigus (foliaceus or paraneoplastic), lichen planus, alopecia areata |
| Endocrine Disorders | Addison disease, graves disease, Cushing's disease |
| Renal and Hepatic Diseases | Glomerulonephritis, autoimmune hepatitis |
| Systemic Autoimmune Diseases | SLE, Sjögren's syndrome, systemic sclerosis, graft-versus-host disease |
Gross Pathology
On gross pathology, a well circumscribed mass that is locally invasive is a characteristic finding of thymoma.
Microscopic Pathology
On microscopic histopathological analysis, round cells, with ample vacuolated cytoplasms, and fat droplets are characteristic findings of thymoma.
Video
{{#ev:youtube|wfyixp6JxQM}}
References
- ↑ C. Buckley, D. Douek, J. Newsom-Davis, A. Vincent & N. Willcox (2001). "Mature, long-lived CD4+ and CD8+ T cells are generated by the thymoma in myasthenia gravis". Annals of neurology. 50 (1): 64–72. PMID 11456312. Unknown parameter
|month=ignored (help) - ↑ J. V. Souadjian, P. Enriquez, M. N. Silverstein & J. M. Pepin (1974). "The spectrum of diseases associated with thymoma. Coincidence or syndrome?". Archives of internal medicine. 134 (2): 374–379. PMID 4602050. Unknown parameter
|month=ignored (help) - ↑ "http://www.iarc.fr/en/publications/pdfs-online/pat-gen/bb10/BB10.pdf" (PDF). Retrieved 26 February 2014. External link in
|title=(help) - ↑ "http://www.iarc.fr/en/publications/pdfs-online/pat-gen/bb10/BB10.pdf" (PDF). External link in
|title=(help)