Seborrheic Keratosis – Sign of Leser Trelat

The Sign of Leser Trelat is a paraneoplastic syndrome that occurs when patients suddenly develop numerous seborrheic keratoses due to an internal malignancy and I occasionally encounter this phenomenon in both my The Woodlands dermatology and Conroe dermatology clinics.  A paraneoplastic syndrome is a non-cancerous symptom or sign that is temporally associated with an underlying cancer.  The most common internal malignancy causing the Sign of Leser Trelat is stomach adenocarcinoma in 60% of all cases.  The other cancers that may cause the Sign of Leser Trelat are: lymphoma, breast cancer, squamous cell cancer of the lung.  In order for the seborrheic keratoses to be the Sign of Leser Trelat, they must arise at the time of the internal malignancy and resolve when the malignancy resolves or is treated.