Cutaneous myoepithelioma: a clinicopathologic and immunohistochemical study of 14 cases.

摘要: Analogous to mixed tumors of salivary glands (" pleomorphic adenomas" ), cutaneous chondroid syringomas" ) contain a ductal (epithelial) component and variably prominent myoepithelial component. Tumors showing purely differentiation (myoepitheliomas) have only recently been recognized arise in the dermis, date very few cases described. To characterize these further, 14 were retrieved from authors' consult files. Eleven patients male 3 female; their median age was 22.5 years (range, 10 63 years), 7 between 20 old. Tumor size ranged 0.5 2.5 cm (mean, 1.1 cm). Most arose on extremities: 6 upper limbs, lower 1 each back nose. Ten limited 5 also extended into superficial subcutis. Thirteen myoepitheliomas (lacking differentiation), tumor carcinoma (exhibiting severe cytological atypia high mitotic rate). Histologically, solid, composed ovoid spindled, histiocytoid, or epithelioid cells with no significant stroma, predominantly lobulated, cords nests epithelioid, plasmacytoid, spindled reticular architecture chondromyxoid collagenous/hyalinized stroma. One solely plasmacytoid (hyaline) cells, exhibited extensive adipocytic differentiation. Among 13 myoepitheliomas, mitoses 0 per high-power fields (HPFs) 1.5); 8 contained mitoses. The had 39 HPFs. By immunohistochemistry, all reactive for epithelial markers (keratins and/or membrane antigen [EMA]); (93%) expressed S-100 protein, 11 (91%) calponin, (79%) EMA, 9 (64%) keratins, (57%) smooth muscle actin, (50%) glial fibrillary acidic (27%) p63, (17%) desmin. All without keratin staining diffusely positive showed solid growth pattern. Follow-up available (median follow-up, 40 months; range, months years); (38%) recurred locally, (13%) metastasized lymph nodes. case that resulted recurrence metastasis highest rate (6 HPFs) cytologically benign tumors. information not carcinoma. This study suggests approximately 50% are distinctive lesions proliferation abundant eosinophilic syncytial cytoplasm, which often lack immunostaining keratin, whereas remainder demonstrate focally myxoid stroma similar counterparts gland soft tissue. Whereas most behave fashion, there is apparently risk local but low metastatic potential.