Primary Malignant Melanoma of the Esophagus: An Electron Microscopic Study

Frable, William J., Kay, Saul, and Schatzki, Peter: Primary malignant melanoma of the esophagus: An electron microscopic study. Am. J. Clin. Pathol. 58: 659–667, 1972. An ultrastructural study of a primary malignant melanoma in the esophagus is reported. The tumor cells contain membrane-bound dense material consistent with melanin and a rare pre-melanosome. The latter structure was not typical, lacking the usual crystalline pattern or cross-linking. This structure was interpreted as a stage in the development of melanin, closer to the mature product. There was a junctional nesting of mein noblasts over a wide area of grossly normal-appearing esophageal mucosa reminiscent of some esophageal squamous cell epitheliomas. This type of tumor extension contributes to the poor prognosis.