A case of laparoscopic partial hepatic S7 resection for postoperative liver metastasis of rectal malignant melanoma

Background Anorectal malignant melanoma (ARMM) has an extremely poor prognosis, and there is no report of resection of liver metastases so far. We report herein a rare case of postoperative laparoscopic partial hepatic S7 resection for rectal malignant melanoma. Case presentation A 51-year-old female patient with a diagnosis of an ARMM underwent a laparoscopic rectal amputation. Eleven months later, computed tomography (CT) revealed a 14-mm nodule in liver segment 7 (S7), which was diagnosed as a hepatic recurrence of the ARMM. Because no other recurrences were found, a laparoscopic partial resection of S7 was performed. Pathological analysis found intracellular melanin deposition, and immunostaining was S-100 (+), HMB-45 (+), and SOX-10 (+). Based on these findings, a liver metastasis of malignant melanoma was diagnosed. The patient is alive 7 months after the second surgery and has so far experienced no recurrences. Conclusion We reported an extremely rare case of a laparoscopic resection of a liver metastasis following surgery for ARMM.