[Eccrine porocarcinoma with extensive cutaneous metastasis].

BACKGROUND

Porocarcinoma is a malignant tumour of the eccrine sweat duct, arising from acrosyringium. The tumoral lesions involve the deep dermal tissue.

CASE REPORT: We report the case of an 84 year-old woman, suffering from a porocarcinoma, extensively involving the major part of the left lower limb. The first symptoms appeared two years ago. Hundreds of metastatic papules and small nodules were present, isolated or confluent into large plaques. The clinical picture was very close to lymphangioma. Diagnosis was confirmed by histopathologic examination. Radiotherapy was useful short-term, allowing partial flattening of the lesions and improving lymphatic drainage, thus providing comfort for the patient. It did not prevent a later progression of the tumoral process.

DISCUSSION: Porocarcinoma is a rare tumour that usually appears as a single nodule or a plaque, arising from a preexistent eccrine poroma, or developing de novo. Two histopathological variants are described: trabecular or epidermotropic. This latter form, observed in the present case, is more aggressive, leading to frequent local recurrences and/or metastases. Our report is exceptional: the literature shows only one other case with such widespread cutaneous involvement. The clinical course of our case is discussed.