The sign of Leser-Trelat in a case of adenocarcinoma of the lung

This is what we believe to be the first report of the sign of Leser-Trelat in association with occult adenocarcinoma of the lung. The sign of Leser-Tr elat is proposed as a sign of possible occult malignancy, despite various s uggestions to the contrary. Also, it is suggested that a tumor-produced hum oral factor (eg, transforming growth factor-alpha [TGF-alpha]) could be res ponsible for both the acute eruption of the monomorphous seborrheic keratos es and the nearly concomitant development of acanthosis nigricans, which oc curred in our case. The possible distinction between a hyperplastic and a n eoplastic origin of various types of seborrheic keratosis is discussed in r elation to this hypothetical humoral factor. In addition, we suggest a refi nement of the definition of the sign of Leser-Trelat and discuss the use of "sign of Leser-Trelat" and "syndrome of Leser-Trelat" in relation to physi cal findings. All patients with the sign of Leser-Trelat should undergo a t horough evaluation for occult malignancy.