Patient with primary gastric melanoma (PGM), 18-FDG-PET/CT scan.
PGM is a rare clinical entity. Most melanomas identified in the stomach represent metastases from cutaneous sources.
Although the cell of origin has not been identified since normal stomach epithelium lacks melanocytes, possible etiologies for the occurrence of primary melanoma have been described. Ectopic migration of melanocyte precursors or differentiation of the APUD cells to melanocytes has been advocated as possible mechanism for the development of malignant melanoma. Furthermore, benign melanosis of the stomach has been reported in association with melanoma of the esophagus documenting the presence of melanocytes in the stomach, rarely.
Posted on 01.09.18