Primary malignant melanoma of the esophagus.

A case of primary malignant melanoma of the esophagus in a 74-year-old male is described. There was a diffuse pigmentation of the lower third of the esophagus macroscopically. Sections from this area revealed melanocytes in the basal layer of the epithelium. This melanosis was not caused by malignant melanoma cells, but obviously by preexisting ectopic and pigmented melanocytes a condition for which the term "esophageal melanocytosis" is proposed. It is suggested that esophageal melanocytosis as well as the presence of junctional changes may determine the primary nature of malignant melanoma of the esophagus. Furthermore, in order to outline the histologic criteria and the pathological features of primary esophageal melanomas, 64 cases have been reviewed.