Soft tissue myoepithelial carcinoma.
BACKGROUND
Myoepitheliomas are tumors composed predominantly or exclusively of myoepithelial cells, usually arising in salivary glands. Cutaneous/soft tissue localization is very rare, especially for the malignant myoepitheliomas.


METHODS
We presented a case of myoepithelial carcinoma involving subcutaneous adipose tissue of the left forearm in a woman aged 62 years. The tumor was composed of epithelioid and hyaline cell types, arranged in diffuse sheets, nests and loose clusters within hyalinized and myxoid matrix. The neoplasm displayed high-grade cytologic atypia with some cells having pleomorphic, hyperchromatic nuclei, and others showing vesicular nuclei, large nucleoli with scattered bizarre giant cells. High mean mitotic count of 7 mitoses/10 high power filds and extensive necrosis favoured the diagnosis of malignancy. Immunohistochemical staining was positive for cytokeratin (AE1/AE3), epithelial membrane antigen, S-100 protein, glial fibrillary acidic protein, and vimentin.


CONCLUSIONS
Considering the subcutaneous localization, myoepithelial immunophenotype and high-grade cytologic atypia the neoplasm was classified as a soft-tissue myoepithelial carcinoma.
Stojsić
Zorica
Z
School of Medicine, Institute of Pathology, Belgrade, Serbia and Montenegro. zstoj@infosky.net
Brasanac
Dimitrije
D
Bacetić
Dragoljub
D
Janković
Radmila
R
Drndarević
Neda
N
D005260:Female; D005542:Forearm; D006801:Humans; D008875:Middle Aged; D009208:Myoepithelioma / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D050151:Subcutaneous Fat / Q000473:pathology*