Document Type

Poster

Publication Date

Spring 4-18-2026

Publisher

University of Nevada, Las Vegas

Publisher Location

Las Vegas (Nev.)

Abstract

Introduction: Mucinous neoplasm of the anus is an uncommon malignancy, representing less than 3% of all anal cancers. Even more rare is extra-appendiceal mucinous neoplasm. As a result, limited literature exists to define diagnostic strategies and optimal management. Our case report details the presentation and management of a patient with recurrent mucinous neoplasm of the anus. Methods: A retrospective chart review was performed which includes clinic documentation., operative notes, pathology reports. Results: The patient is a 76-year-old male with a history of T3N0M0 anal mucinous carcinoma diagnosed in 2015 and treated with neoadjuvant chemoradiation with complete pathological response. In 2024, a surveillance colonoscopy showed a nonobstructing, fungating, 2cm anal mass, and biopsy demonstrated adenocarcinoma with mucinous features. MRI of the pelvis revealed a distal anal canal mass extending from the right perianal skin across the midline to the left perianal skin with invasion of the internal sphincter. PET/CT showed no evidence of metastatic disease. The patient subsequently underwent robotic abdominoperineal resection with permanent end colostomy and robotic vertical rectus muscle flap reconstruction of the perineum with Ovitex biosynthetic mesh. His postoperative course was uncomplicated, and was discharged home with home health services on postoperative day six. Final surgical pathology demonstrated atypical mucinous proliferation with morphologic features consistent with extra-appendiceal mucinous neoplasm. Conclusion: We present a rare case of an extra-appendiceal mucinous neoplasm of the anus. It remains unclear whether this process represents recurrence of the patient's prior malignancy with treatment-related changes or the development of a secondary low-grade neoplastic process.

Controlled Subject

Cancer; Anus; Case reports

Disciplines

Oncology | Pathology | Surgery

File Format

PDF

File Size

5600 KB

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/


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