Malignant mesothelioma
| Malignant mesothelioma | |
|---|---|
| Diagnosis in short | |
 Malignant mesothelioma. H&E stain. | |
|
| |
| LM | infiltrative atypical cells (epithelioid, spindled or both) |
| Subtypes | biphasic mesothelioma, epithelioid mesothelioma, desmoplastic mesothelioma, sarcomatoid mesothelioma. |
| LM DDx | mesothelial hyperplasia, fibrosing pleuritis, adenocarcinoma - esp. lung |
| IHC | calretinin +ve, D2-40 +ve, CK5/6 +ve, WT-1 +ve, CK7 +ve, CEA -ve, TTF-1 -ve |
| Site | lung, peritoneum |
|
| |
| Clinical history | asbestos exposure, smoking |
| Prevalence | rare |
| Prognosis | very poor |
Malignant mesothelioma, also mesothelioma, is a form of cancer. It arises from the mesothelium.
It should not be confused with benign multicystic mesothelioma and benign papillary mesothelioma.
General
- Poor prognosis - median survival <12 months.[1]
Locations:
- Lung.
- Primary peritoneal.
Epidemiology:
- Strong association with asbestos exposure.
Conditions associated with asbestos exposure (mnemonic PALM):[2]
- Pleural plaques.
- Asbestosis.
- Lung carcinoma.
- Malignant mesothelioma.
Possible association with asbestos exposure:
Microscopic
Features:[4]
- Infiltrative atypical cells - key feature.
- +/-Epithelioid cells - may be cytologically bland, i.e. benign appearing.
- Variable architecture: sheets, microglandular, tubulopapillary.
- +/-Psammoma bodies.
- +/-Spindle cells.
- +/-Epithelioid cells - may be cytologically bland, i.e. benign appearing.
- +/-Ferruginous body - strongly supportive.[5]
- Looks like a (twirling) baton - segemented appearance, brown colour.
- Thin (asbestos) fiber in the core.
Note:
- Asbestos body is not strictly speaking a synonym for ferruginous body.
DDx:[6]
- Fibrosing pleuritis.
- Mesothelial hyperplasia.
Images
Ferruginous body. (WC)
MM - low mag.
MM - intermed. mag.
MM - high mag.
MM - very high mag.
MM - calretinin - intermed. mag.
MM - calretinin - high mag.
Subtypes
List of subtypes - mnemonic BEDS:[6][4]
- Biphasic mesothelioma.
- 10%+ of epithelioid & 10%+ sarcomatoid.
- Epithelioid mesothelioma.
- Desmoplastic mesothelioma.
- Should be 50%+ dense tissue with storiform pattern & atypical cells.
- Sarcomatoid mesothelioma.
Stains
- PASD -ve.
- Mucicarmine -ve.
- Typically +ve in adenocarcinoma.
IHC
Mesothelioma versus mesothelial hyperplasia
Features:[7]
- EMA +ve ~100% (vs. ~10%).
- Desmin -ve ~5% (vs. ~85%).
- GLUT1 +ve ~50% (vs. ~10%)
- p53 +ve ~50% (vs. ~2%).
Mesothelioma versus adenocarcinoma
- Several panel exists - no agreed upon best panel.[8]
- Usually two carcinoma markers + two mesothelial markers.
Panel:[8]
- Mesothelial markers:
- Calretinin.
- WT-1.
- D2-40.
- CK5/6.
- Carcinoma markers:
- CEA (monoclonal and polyclonal).
- TTF-1.
- Ber-EP4.
- MOC-31.
- CD15.
See also
References
- ↑ Mineo, TC.; Ambrogi, V. (Dec 2012). "Malignant pleural mesothelioma: factors influencing the prognosis.". Oncology (Williston Park) 26 (12): 1164-75. PMID 23413596.
- ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 375. ISBN 978-1416054542.
- ↑ Reid, A.; Heyworth, J.; de Klerk, N.; Musk, AW. (Nov 2009). "Asbestos exposure and gestational trophoblastic disease: a hypothesis.". Cancer Epidemiol Biomarkers Prev 18 (11): 2895-8. doi:10.1158/1055-9965.EPI-09-0731. PMID 19900938.
- ↑ 4.0 4.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 156. ISBN 978-0781765275.
- ↑ URL: http://medical-dictionary.thefreedictionary.com/asbestos+body. Accessed on: 4 November 2011.
- ↑ 6.0 6.1 Corson, JM. (Nov 2004). "Pathology of mesothelioma.". Thorac Surg Clin 14 (4): 447-60. doi:10.1016/j.thorsurg.2004.06.007. PMID 15559051.
- ↑ Hasteh, F.; Lin, GY.; Weidner, N.; Michael, CW. (Apr 2010). "The use of immunohistochemistry to distinguish reactive mesothelial cells from malignant mesothelioma in cytologic effusions.". Cancer Cytopathol 118 (2): 90-6. doi:10.1002/cncy.20071. PMID 20209622.
- ↑ 8.0 8.1 Marchevsky AM (March 2008). "Application of immunohistochemistry to the diagnosis of malignant mesothelioma". Arch. Pathol. Lab. Med. 132 (3): 397-401. PMID 18318582. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=132&page=397.