[Malignant eccrine poroma. Apropos of 2 facial sites]

The authors report 2 cases of malignant eccrine poroma (M.E.P.) located on the face: one on the auricle which was treated by triangular shape resection, the other on the nasal tip which underwent a reconstruction with a Converse scalping flap after large surgical resection removed underlying skin and cartilages. A study reviewing the main features of M.E.P. is presented on the basis of these clinical cases. M.E.P. are skin appendage tumors originating from the intra epithelial portion of the eccrine sweat duct. Such denominations as malignant hidroancanthoma, eccrine porocarcinoma, poroepithelioma, correspond to the same tumor. They are very rare: 73 cases have been reported in the world literature with only 12 located on the face; the main localisations involve the lower extremities, but the palmo plantar areas are involved more frequently in benign tumors. Elderly people over 60 are concerned in almost all cases. Many of the patients have noticed a lesion for years before a diagnosis was made suggesting one of the etiopathogenic theories that M.E.P. may result from malignant transformation of a benign eccrine poroma. Their clinical appearance is non specific nevertheless their malignant nature is suspected and misdiagnosis with basal cell carcinoma is frequent. Microscopic findings demonstrate the diagnosis by showing the association of malignant features with eccrine poroma. These tumours invade both by superficial spead and by deep extension towards dermal and hypodermal structures. Their prognosis is marked by the rapid development, in approximately on half of cases, of cutaneous, lymp node and visceral metastases. Clinical and histological examination have no prognostic value exception the case of deep invasion.(ABSTRACT TRUNCATED AT 250 WORDS)