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.