Multimodal treatment and long-term survival in a rare case of melanoma with pancreatic and splenic metastases: a case report and literature review

Background Patients with melanoma frequently develop metastases, and managing these cases, especially aggressive, rare types such as pancreatic metastasis, remains challenging. To date, no consensus on treatment has been reached. Case presentation This study presents an uncommon case of a 55-year-old man with rapidly progressive metastatic melanoma following initial lower-extremity melanoma resection. Within 5 months postoperatively, he developed widespread metastases, including lesions in the chest, back, calves, axilla, pancreas, and spleen, an exceptionally rare presentation. The patient received various treatment regimens, including toripalimab monotherapy, combination therapy with anlotinib, and combination therapy with temozolomide. Ultimately, surgical resection of the pancreatic and spleen metastases revealed a BRAF V600 mutation, permitting successful transition to targeted therapy with dabrafenib plus trametinib. As of the most recent follow-up on March 6, 2025, the patient remains stable with long-term survival. Conclusion This case report, along with the subsequent literature review, emphasizes the need for continued treatment and vigilance of molecular monitoring in patients with advanced melanoma, as well as the critical role of multidisciplinary team collaboration in managing complex metastases. Surgical resection and targeted therapy might yield favorable outcomes for select patients with melanoma and pancreatic and splenic metastases.