Rare skin appendage tumour on the right leg: a case of primary cutaneous cribriform carcinoma.

A woman in her 60s presented with a longstanding history of a purplish, fleshy and pedunculated nodule on the right shin on a background of bilateral lower limb lymphoedema. A shave biopsy with double curettage of the base of the lesion revealed a nodular tumour with hyperchromatic basaloid cells arranged in a cribriform pattern and encircling eosinophilic substance. Immunohistochemistry staining showed cells positive for pancytokeratin, low molecular weight keratin, BerEP4 and negative for cytokeratin 20. There were no clinical or radiological features of primary visceral malignancy. These histological and immunohistochemical features favour a diagnosis of primary cribriform carcinoma of the skin. This is a rare, indolent skin appendage tumour of presumed apocrine origin with no reported cases in the literature of metastasis or local recurrence after excision.