Primary Gastric Malignant Melanoma in a 68-Year-Old Woman: A Case Report and Review of the Literature

Non-cutaneous melanoma is a very rare clinical entity. Gastric melanoma can be primary or secondary, but determining their nature is in most cases very challenging. To date, very few cases of primary gastric melanoma have been described in the literature. We report the first case of primary gastric melanoma documented in a Romanian patient, confirmed through clinical, imagistic, and pathological diagnosis. A 68-year-old female patient presented to our hospital with complaints of dyspepsia, abdominal pain, and weight loss. Esophagogastroduodenoscopy revealed two large sessile masses in the gastric fundus, which was histologically compatible with melanoma; immunohistochemistry staining was positive for vimentin, S100 protein, HMB45 antibody and Melan A/MART1, and negative for pan-CKAE1/AE3, leukocyte common antigen and DOG1. Extensive dermatological and ophthalmological examinations did not identify a primary lesion. The patient was therefore diagnosed with primary melanoma of the stomach. At the time of the diagnosis, multiple bone and pulmonary metastases were detected and considering the poor general status of the patient, surgery was not recommended. She died three months following diagnosis. A review of the literature identified only 32 other reported cases of primary gastric melanoma, all in individuals ≥50 years of age and most of them in male patients. Partial or total gastrectomy was the usual treatment of choice, but prognosis was overall poor. Awareness of this rare condition must be increased among healthcare providers, as early detection can improve survival chances.