Morphological and immunophenotypic variations in malignant melanoma.
Affiliation
Department of Histopathology, Christie Hospital, Manchester, UK.Issue Date
2000-05
Metadata
Show full item recordAbstract
A variety of cytomorphological features, architectural patterns and stromal changes may be observed in malignant melanomas. Hence, melanomas may mimic carcinomas, sarcomas, benign stromal tumours, lymphomas, plasmacytomas and germ cell tumours. Melanomas may be composed of large pleomorphic cells, small cells, spindle cells and may contain clear, signet-ring, pseudolipoblastic, rhabdoid, plasmacytoid or balloon cells. Various inclusions and phagocytosed material may be present in their cytoplasm. Nuclei may show bi- or multi-nucleation, lobation, inclusions, grooving and angulation. Architectural variations include fasciculation, whorling, nesting, trabeculation, pseudoglandular/pseudopapillary/pseudofollicular, pseudorosetting and angiocentric patterns. Myxoid or desmoplastic changes and very rarely pseudoangiosarcomatous change, granulomatous inflammation or osteoclastic giant cell response may be seen in the stroma. The stromal blood vessels may exhibit a haemangiopericytomatous pattern, proliferation of glomeruloid blood vessels and perivascular hyalinization. Occasionally, differentiation to nonmelanocytic structures (Schwannian, fibro-/myofibroblastic, osteocartilaginous, smooth muscle, rhabdomyoblastic, ganglionic and ganglioneuroblastic) may be observed. Typically melanomas are S100 protein, NKIC3, HMB-45, Melan-A and tyrosinase positive but some melanomas may exhibit an aberrant immunophenotype and may express cytokeratins, desmin, smooth muscle actin, KP1 (CD68), CEA, EMA and VS38. Very rarely, neurofilament protein and GFAP positivity may be seen.Citation
Morphological and immunophenotypic variations in malignant melanoma. 2000, 36 (5):387-402 HistopathologyJournal
HistopathologyDOI
10.1046/j.1365-2559.2000.00894.xPubMed ID
10792480Type
ArticleLanguage
enISSN
0309-0167ae974a485f413a2113503eed53cd6c53
10.1046/j.1365-2559.2000.00894.x