[Malignant eccrine poromas (poro-epitheliomas, porocarcinomas)]

Malignant eccrine poromas set first of all the problem of the diagnosis of intra-epidermic cutaneous tumours. The epidermic symbiosis of the neoplastic cells and their natural disposition to keratinization and to differentiation of excretosudoral structures are their main pathological characteristics; they account for their acrosyringeal origin. The multitude of epidermotropic metastatic resurgences by the lymphatic route and their transcutaneous expulsion characterizes the evolution of these tumours. According to the study of the 8 cases published since 1956 and of this personal case the precession of a benign porosyringeal tumour seems probable but has never been proved.