Malignant melanomas are malignant tumors arising from the skin cells called melanocytes (5). Its incidence is 3.4% among all cancers (6), and its prognosis is generally poor. Five-year survival rate of Stage 4 malignant melanoma patients was found to be only 14% (7).
Excisional biopsy is still the golden standard for diagnosis (8). Presence of various morphologic variants of malignant melanoma makes pathologic diagnosis extremely difficult (9), and accurate pathologic diagnosis is important for early diagnosis and treatment.
Malignant melanoma can metastasize to all the organs but it is especially known to metastasize to the gastrointestinal system frequently (10). In the gastrointestinal system, it metastasizes most frequently to the small intestines, large intestines and the anorectal area. Gastric metastasis is known to be very rare (11). However, there were metastases to the stomach and duodenum in our case.
Gastrointestinal melanomas are frequently characterized with non-specific symptoms and signs like abdominal pain, nausea, dysphagia, upper and lower GIS bleeding and melena (12). Abdominal pain, anemia and melena were reported in our case.
Endoscopic evaluation has an important place in the diagnosis of gastrointestinal system melanoma. Black pigmented lesions, submucosal nodules, ulcerated lesions and masses with polypoid structure can be detected with endoscopy. Bull’s eye appearance in the lesion is characteristic in barium analyses (13). In our case, numerous black pigmented nodular lesions and necrotic ulcers were detected in endoscopic examination.