We've made a brief account of Carcinoma Cuniculatum and after reviewing the references, we found four cases which didn't appear on the foot as usual. We've reported a 68-year-old man, with a lesion on the back of his left hand; it had been present six years and had recurred after a surgical excision. On the clinical point of view, the lesion is a roughly oval 7 X 5 cm., plaque formed by the junction of small violaceous nodules. The surface is keratotic and it presents multiple sinuses from where a white, greasy material oozed out. Concerning the pathological findings we can observe that the papillomatous surface squamous epithelium penetrated into the underlying tissue. The epithelium contained sinuses which were filled with keratin. Occasionally the epithelium showed individual cell keratinization. The squamous epithelium was well differentiated and a feature seen was intra-cellular oedema, with sheets of uniform, pale, staining epithelium. Mitotic activity was low and confined to the basal layers. The tumour was accompanied by a fibrous stroma which was somewhere heavily infiltrated by chronic inflammatory cells. The treatment consisted of a wide excision and graft. As to the aetiology of the tumour the different authors suggest several possibilities, since the enduring trauma, chronic inflammation, burn scars, radiation, arsenic ingestion until the viral aetiology. McKee and Wilkinson suggest that it's a multifactorial process, playing the wart virus the main part in the breaking out of the tumour.