Abstract
A 70-year-old man with a complaint of bleeding at defecation and anal pain was admitted to our hospital. A type 2 tumor was detected in the anal canal. Biopsy examination under unbar anesthesia revealed small-cell carcinoma, which was removed by abdominoperineal resection. Histopathological examination revealed a well-differentiated villous adenocarcinoma and solid nest-like cancer cells. A round cell that proliferated to solid alveolar form was positive for CD56, chromogranin A, and synaptophysin, and was diagnosed as neuroendocrine cell carcinoma. We administered 6 rounds of FOLFOX4 therapy as adjuvant chemotherapy. At 12 months after surgery, lung and liver metastases were observed on CT, and mFOLFOX6 therapy was started. Neuroendocrine cell carcinoma of the anal canal is extremely rare and its prognosis is poor. Surgery alone is not enough for radical cure and combined treatment is required.
