Basal cell carcinoma with ductal differentiation

Case 1012  9.5.14 (R. Carr)  M 79 

Large, deeply situated basaloid tumour showing ductal differentiation, eosinophilic hyaline deposits and a rippled trabecular pattern.  Rather spiradenoma-like, but lacked the dual cell population or lymphocytic infiltration in the tumour. Retraction artefact and peripheral palisading not shown. 

Stains: Ber-EP4 diffuse strong +ve; EMA highlights ducts. 

Learning points: ductal differentiation not uncommon in BCC; rippled trabecular pattern suggests sebaceoma, BCC, trichoblastoma (should have papillary mesenchymal cells) but not hidradenoma or spiradenoma; on EMA ducts punched out in BCC and hidradenoma but intra-cytoplasmic vacuoles indent the nucleus in sebaceous tumours. 

Case 2591  11.6.20 (S. Taibjee)  F 54 ear ?  BCC 

Infiltrative growth pattern with narrow cords of cells, forming tubules in places, surrounded by sclerotic and mucinous stroma.  Cells show abnormal mitoses and apoptotic cells visible.  Ber EP4 +ve; EMA –ve (against MAC) 

DD: DTE – S. Taibjee makes point that DTE usually show ductal differentiation.