Primary anorectal malignant melanoma treated with neoadjuvant chemoradiotherapy and sphincter-sparing surgery: A case report

Primary anorectal (PA) malignant melanoma (MM) is a rare disease associated with a high mortality rate. The most appropriate treatment strategy for PAMM remains controversial. A 55-year-old female patient, who was misdiagnosed with locally advanced rectal carcinoma, was treated with preoperative radiotherapy and concurrent oral capecitabine. During the therapy, grade 1 leukopenia occurred, however, there was no interruption to treatment. Following chemoradiotherapy, a computer tomography scan identified that the tumor had shrunk significantly and the original enlarged lymph nodes had disappeared. Eight weeks after completion of chemoradiotherapy, sphincter-sparing surgery was performed on the patient and based on the postoperative pathological result, MM was diagnosed. At the time of writing, the patient has survived disease-free for 15 months and at the most recent follow-up examination the Karnofsky Performance Scale score was 100. The therapeutic regimen of neoadjuvant concurrent chemoradiotherapy together with sphincter-sparing surgery is considered to be an optimal choice for patients with PAMM. However, further studies are required to evaluate the efficacy and clinical utility of this therapeutic regimen.