Benign Tailgut Cyst Masquerading as a Hemorrhoid

Abstract

1Division of Anatomic Pathology, Vancouver General Hospital, Department of Pathology & Laboratory Medicine, University of British Columbia; 2Pezim Clinic; 3Department of Surgery, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia Correspondence: Dr Joyce M Leo, Division of Anatomic Pathology, Vancouver General Hospital, 910 West 10th Avenue, Vancouver, British Columbia V5Z 4E3. Telephone 604-875-4480, fax 604-875-4797, e-mail joyce.leo@alumni.ubc.ca Received for publication January 28, 2014. Accepted Febraury 7, 2014 CASE PRESENTATION A 79-year-old man presented with a 1.5-year history of a prolapsing cystic structure located within the anterior anal sphincter, clinically suggestive of a hemorrhoid. Physical examination demonstrated a cystic mass within the anterior anal verge, measuring up to 3 cm in maximum diameter. During the ensuing surgical procedure, the cystic structure was opened and contained thick purulent fluid; no solid areas were present. The microscopic appearance (Figure 1) was of a cyst partially lined with squamous and ciliated tall columnar epithelium (short arrows) containing occasional goblet cells (long arrows); there was no evidence of dysplastic epithelial changes. Subjacent scattered bundles of fibrous connective tissue and small blood vessels were present within the cyst wall. The histological features were consistent with a benign tailgut cyst.