Rationale:
Adenocarcinoma of the anal canal is an uncommon malignancy. Primary adenocarcinoma, in particular, is extremely rare.
Patient concerns:
A 61-year-old man was referred to our institution with complaints of repeated hematochezia.
Diagnosis:
Digital rectal examination revealed a hard palpable ulcer in the anal canal, measuring 2 cm × 2 cm in size, at the 5 o'clock direction (in the lithotomy position). The pelvic enhanced magnetic resonance imaging revealed anal verge occupying mass. A diagnosis of carcinoma of the anal canal was considered. Colonoscopic examination revealed a poorly differentiated adenocarcinoma of the anal canal.
Interventions:
The patient underwent abdominoperineal resection (APR) of the rectum, and was administered 6 courses of adjuvant chemotherapy with mFOLFOX.
Outcomes:
The patient was followed up for more than 1 year after operation, and no local recurrence or distant metastasis occurred.
Lessons:
The diagnosis and treatment of this disease is still a huge challenge because its incidence is very low. A study of more cases is required for uniformity in diagnosis and for the development of treatment protocols.