Leser-Trelat sign in mother and daughter with breast cancer.

The Leser-Trelat sign is the sudden appearance and rapid increase in size and number of seborrhoeic keratoses in association with cancer. Twenty cases of this unusual phenomenon have so far been reported in the world literature. More than half involve adenocarcinomas and none was shown to be familial. We report a unique example of a 41-year-old black female and her 74-year-old black mother, both of whom have demonstrated classical clinical-pathological evidence of the Leser-Trelat sign and adenocarcinoma of the breast. The remainder of the family history was negative for cutaneous lesions and cancer. The aetiological and pathogenetic significance of the Leser-Trelat sign in association with carcinoma of the breast in this mother and daughter remains obscure.