[The Leser-Trélat symptom: report of two cases (author's transl)].

The sudden occurrence and rapid increase in size and number of seborrheic keratoses is considered to be a symptom of internal malignancy. But many authors did not fully agree with this finding. We report two cases respectively associated, the first with a mycosis fongoides, the second with a bronchial squamous cell carcinoma. These observations are compared with thin cases previously published in the dermatological literature (13 patients). According to Dantzig the commonest associated malignancy is an adenocarcinoma, and the most frequent site the stomach. But there are also report of acute leukemia, mycosis fongoides, Sézary and lymphocytic lymphoma. The mechanism of the simultaneous growth of the lesions remains unknown and may be purely coincidental. Other case reports and several criteria still to be defined are needed before we accept this symptom as a malignancy marker.