[Generalised type of acquired dermal melanocytosis]

A 55 year-old man with a leiomyosarcoma of the rectum and its multiple metastatic lesions in the liver was evaluated for the presence of multiple pigmented macules. The initial lesion was noticed on the face at the age of 53 years old, and then extended to the upper extremities and the back, and became darkened. On physical examination, there were extensive and multiple blue gray macules on the face, upper extremities, shoulders, and the back. Grey flecks on the both palpebral conjunctivas, blue-grey flecks on the palate and blue and brown pigmentation of the gingiva were also noticed. The serum levels of alpha-MSH and growth hormone showed about twice as much as normal range. By light and electron microscopic examinations, pigment bearing cells were identified as dermal melanocytes. From these findings, we diagnosed this case as a generalized type of acquired dermal melanocytosis.