Jefferson Tran, 1, Rolando Oro, MD2, Tung Tran, MD1 1Texoma Medical Center, Denison, TX; 2TMC, Denison, TX
Introduction: Malignant melanoma is a form of skin cancer which has a tendency for metastasis, most commonly to lymph nodes, lung, liver, and brain. Primary melanoma rarely metastasizes to the colon. We report a rare case of metastatic melanoma to the cecum 10 years after surgical resection of the primary cutaneous tumor.
Case Description/Methods: A 72-year-old man presented with 1 year of intermittent vague right-sided abdominal pain, occasional diarrhea, fatigue and weight loss of 20 lbs. He had a history of cutaneous melanoma on the right shoulder which had been treated by a wide margin resection 10 years prior. He was found to have anemia with Hgb of 9.9. CT scan showed a 5 cm soft tissue mass in the cecum suggestive of a neoplasm. The patient underwent a colonoscopy which showed a 5 cm ulcerated mass in the cecum. The mass oozed fresh blood. Spot ink was injected to tattoo the area. Multiple biopsies were taken. Pathology showed multiple sheets of large pleomorphic cells with a moderate amount of eosinophilic cytoplasm and bubbly chromatin. Mitotic figures were abundant. There was associated necrosis. Immunostains SOX10 and HMB45 were positive, consistent with metastatic melanoma. The patient underwent a right hemicolectomy with end-to-end ileocolic anastomosis. Pathology confirmed the diagnosis of metastatic melanoma with involvement of the mucosa, submucosa and muscularis. The surgical margins and all 22 lymph nodes were negative of tumor. BRAF mutation was negative. The patient was placed on immunotherapy with no adverse effects. All his symptoms resolved. One year later, the patient underwent a follow-up colonoscopy which showed no recurrence of melanoma.
Discussion: The incidence of malignant melanoma has been rising around the world, having increased by 360 % since the 1970s. Melanoma has a tendency to spread to other melanocyte-containing organs. Metastatic melanoma to the colon is uncommon due to the relative scarcity of melanocytes in the colon. Surgical resection is indicated for isolated lesion and for symptomatic relief. Cytotoxic chemotherapy is ineffective, but immunotherapy has emerged as a promising treatment option.
Disclosures:
Jefferson Tran indicated no relevant financial relationships.
Rolando Oro indicated no relevant financial relationships.
Tung Tran indicated no relevant financial relationships.
Jefferson Tran, 1, Rolando Oro, MD2, Tung Tran, MD1. C0144 - Metastatic Melanoma to the Cecum 10 Years After Surgical Resection of the Primary Cutaneous Tumor, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.
