A case of eccrine porocarcinoma: A treacherous mimic and diagnostic challenge.

Eccrine porocarcinoma is a rare malignant dermal appendageal tumor notorious for its varied morphology, both clinically and histologically; and it can pose a considerable diagnostic dilemma to both the dermatologist and the pathologist. Herein, we present a case of a 74-year-old woman with slow-growing nodular masses on both buttocks, reaching a fairly large size over a course of 3 years. Although atypical morphologic features posed significant diagnostic difficulty to both the surgeon and the pathologists, it was eventually diagnosed as eccrine porocarcinoma with focal squamoid features, using immunostains. To our knowledge, this is the second reported case of bilateral eccrine porocarcinoma which highlights the need for awareness of the morphological variations that this entity is capable of producing.