[Pachydermatoglyphy. A sign of malignancy for acanthosis nigricans (author's transl)].

The pachydermatoglyphy corresponds from the clinical point of view to a diffuse palmo-plantar keratodermia, of a yellowish color, characterised by a rough thickening of the finger prints. The presence of the pachydermatoglyphy has been pointed out in six cases of malignant acanthosis nigricans. This was already found in previous descriptions. Pachydermatoglyphy is specially found in malignant acanthosis nigricans, but we have also observed such cases in erythrokeratodermia with pilar keratosis and deafness.