Isolated Pancreatic Metastasis from Malignant Melanoma: Is Pancreatectomy Worthwile?
In 1989, a 29-year-old woman was diagnosed with a dorsal malignant melanoma treated by a wide R0 resection. After 4 years of follow-up (1993), she developed a local recurrence treated by resection; the analysis of sentinel lymph nodes was negative. Sixteen years after initial diagnosis (2005), she presented an epigastric pain and a 5 kg weight loss. An echoendoscopy revealed a 50 mm tumor located in the head of the pancreas, without vascular invasion and the biopsy confirmed an IPMMM. Exhaustive radiologic staging did not reveal any other metastasis [Figure and ]. Primary chemotherapy was not delivered because of the long delay between resection of the primary tumor and recurrence and the only modest antitumor activity that could be expected with the conventional cytotoxic regimen (i.e., dacarbazine single-agent) used in metastatic melanoma. PD was performed and the histological analysis revealed a 60 mm tumor with clear resection margins. Immunohistochemistry detected the expression of protein S100, HMB45 but not of vimentin and melanA, features compatible with a metastasis of primary melanoma. Due to post-operative hemorrhage (day 7) arising from splenic vessels, the patient was re-operated and a totalization of pancreatectomy was performed. A new intervention was done at day 15 for gastro-jejunal anastomosis leak. Nineteen months after resection (2007), the patient presented a para-aortic lymph node recurrence that was treated by peri-aortic lymph node clearance []. After both initial PD and subsequent resection of the lymph node relapse, adjuvant treatment was not proposed because of (a) poor post-operative courses, (b) potential toxicities in a patient with complete pancreatic exocrine and endocrine insufficiency and (c) lack of available evidence demonstrating any impact of adjuvant systemic treatment in this setting. Since 2007, the patient has been under regular clinical and radiological surveillance without evidence of disease recurrence.