Melanoma with gastric metastases

Abstract

An 81-year-old woman with a history of malignant melanoma who presented with dyspnea and fatigue was found to have metastases to the stomach detected on endoscopy. Primary cutaneous malignant melanoma with gastric metastases is a rare occurrence, and it is often not detected until autopsy because of its non-specific manifestations. M elanoma can spread to any organ, and it is the most common metastatic tumor of the gastro-intestinal (GI) tract; the most commonly involved sites include the small and large bowels and rectum. However, gastric metastases are a rare phenomenon. Because it is uncommon and its clinical manifestations are non-specific, it is often not detected until autopsy (1). Studies show that 60% of patients who die of melanoma are found to have metastases to the GI tract on autopsy, with gastric involvement in approximately 20% of these cases (1Á3). We are reporting a case of melanoma with gastric metastases. We will examine common clinical findings and review both pathological and endoscopic findings as well as discuss treatment options. Case report An 81-year-old woman with history of melanoma presented to the emergency department with a chief complaint of dyspnea and fatigue. Initial laboratory work-up revealed anemia, with hemoglobin of 7.6 gm/dL and hematocrit of 23.8%. She denied any history of melena. Liver function tests revealed alkaline phosphatase 819 unit/L, AST 131 unit/L, ALT 129 unit/L, albumin 2.0 gm/dL, and total bilirubin 0.6 mg/dL. Hepatitis panel was negative. Coagulation profile and basic metabolic panel were unremarkable. Abdominal and rectal exams were unremarkable. One month earlier, a computed tomography (CT) scan of the abdomen with contrast revealed small liver masses, but no gastric lesions were noted. The patient had a history of recurrent acral lentiginous melanoma of the foot 1 year earlier, which was treated with amputation of the fifth toe and oral chemotherapy. She had recurrence of the melanoma on her left leg 6 months earlier, which was treated with radiation and chemotherapy (temozolomide). Given her anemia and history of melanoma, an upper endoscopy was performed. In the stomach, there were multiple hyperpigmented lesions involving the cardia, fundus, and body, all varying in size, shape, and morphology (Figs. 1Á2). Some were macular, and some appeared to be ulcerative and umbilicated. In the duodenum, a solitary hyperpigmented lesion was noted. Multiple cold biopsies were obtained. A digital rectal examination showed non-bleeding internal hemorrhoids. A colono-scopy was also performed which revealed only scattered diverticuli. Pathology revealed that the lamina propria of both the duodenum and stomach was infiltrated by a population of single, atypical, and pigmented discohesive cells (Figs. 3Á4). The cells expressed the melanoma marker HMB-45 on immunohistochemical stains, which were weakly positive for S-100 protein (Fig. 5). Considering these findings in the setting of her recurrent melanoma, we concluded that the patient had malignant melanoma with metastases to the stomach and duodenal bulb. Because of the recurrence of her cancer and failure of chemotherapy, the patient did not wish to have any further treatment. Discussion The average time from diagnosis of a primary cutaneous malignant melanoma to metastasis to the GI tract is 52 months (4). Diagnosis is rarely made before surgery or endoscopy, because associated symptoms are non-specific and only manifest in 1Á4% of patients with metastases; such symptoms include fatigue, nausea, vomiting, abdominal JOURNAL OF COMMUNITY HOSPITAL INTERNAL MEDICINE PERSPECTIVES ae