Leser-Trelat Sign

Excerpt

The sign of Leser-Trelat is considered to be a fairly rare paraneoplastic cutaneous marker of internal malignancy with the hallmark finding being an abrupt eruption of multiple seborrheic keratoses. To date, there have been no standardized or quantified diagnostic criteria defining the sign of Leser-Trelat, but instead, the colloquial definition includes an increase in the number and/or size of the seborrheic keratoses. Seborrheic keratoses (SK) are a nearly ubiquitous benign skin lesion in patients greater than 40 years of age, and generally, even healthy patients may have multiple seborrheic keratoses. This “sign” has been met with a significant amount of skepticism by many considering the commonality of both seborrheic keratoses and malignancy in elderly patients.

The sign of Leser-Trelat was first described by in the 1800s by Edmund Leser and Ulysse Trelat, but instead of eruptive seborrheic keratoses, they were studying the presence of cherry angiomas in oncology patients. In 1900, Hollander was the first to describe seborrheic keratoses in association with malignancy, but the names Leser and Trelat remained affixed to the condition.