Recurrent Metastatic Melanoma Presenting as a Bleeding Gastric Polyp

Abstract

Gastrointestinal metastases of melanomas are uncommon; however, in a patient with a history of melanoma, seemingly benign lesions found on endoscopy warrant a low threshold for tissue analysis. A 64 year old female with hypertension, diabetes mellitus type 2, chronic kidney disease, heart failure, multifactorial normocytic anemia, and stage IIa malignant melanoma of the left ear was admitted for heart failure exacerbation. On hospital day 1, her hemoglobin dropped from 7.1g/dl (baseline 8g/dl) to 5.3g/dl. She was hemodynamically stable and there was no evidence of active bleeding. Her hemoglobin increased to 7.8g/dl after transfusion with 3 units of packed RBCs. Esophagogastroduodenoscopy (EGD) revealed an asymmetric, friable sessile 5 mm polyp in the body of the stomach which was removed by snare electrocautery. A similar polyp was described on EGD in 2013, which was not removed due to GI bleed at that time. Endoscopic examination was otherwise unremarkable. The patient's hemoglobin remained stable and she was discharged with colonoscopy to be done as an outpatient. Analysis of the polyp revealed poorly differentiated adenocarcinoma. Immunohistochemistry was positive for S100, Melan-A, and HMB45 which was consistent with melanoma. PET/CT showed evidence of disease in the right adrenal gland, stomach, duodenum, and multiple nodal stations throughout the small bowel consistent with metastatic melanoma. BRAF and KIT mutations were negative. Dual immunotherapy with Ipilimumab and Nivolumab is the first line treatment for metastatic melanoma. She was started on only nivolumab due to multiple comorbidities and concerns for toxicities. She tolerated therapy and had an excellent response as shown by increased energy and decreased disease burden on her 3 month surveillance PET scan. The recurrence of melanoma with metastasis is suspected given that the resected gastric polyp is likely the same polyp seen on the prior EGD in 2013. Chemotherapy for metastatic melanoma is not very effective, and the patient's significant comorbidities would have precluded chemotherapy. With the emergence of immunotherapy, the potential for prolonged survival measured in years is now a possibility. This case illustrates the importance of pursuing complete evaluation in patients with significant comorbidities as meaningful prolongation of life may be possible in the era of immunotherapy for advanced malignancy.