Anal dysplasia as an incidental finding: the importance of specimen evaluation.

Kavalukas, Sandra L; Yang, Feng; Wexner, Steven D; Nogueras, Juan J

PURPOSE The incidence of anal squamous cell carcinoma (SCC) has increased dramatically in the USA. The squamous intraepithelial lesion (SIL) has been identified as a precursor lesion to SCC, stratifying the abnormality into low grade (LSIL) or high grade (HSIL). There have been studies on the prevalence of incidentally found SCC in haemorrhoidectomy specimens, there are no studies to date on the incidence of dysplasia. The purpose of this study was to establish a baseline incidence of dysplasia that provides helpful information for future epidemiological studies. METHODS A retrospective review of patients who underwent haemorrhoidectomy from 2005-2019. Pathology regarding what type of dysplasia, medications, and diagnoses that may predispose to immunosuppression were collected. RESULTS 810 patients of a mean age of 51.7 (range 20-91) years underwent haemorrhoidectomy. 18 (2.2%) of the patients had abnormal pathology [low-grade squamous intraepithelial lesion (LSIL) =3, high-grade squamous intraepithelial lesion (HSIL) =12, SCC=2, adenocarcinoma=1]. 37 (4.5%) of the entire cohort had some risk factors for immunosuppression: chronic steroid use (9), HIV (13), biologic medications (6), transplant recipients (2) and immunocompromising diseases (4). Only 4/18 patients had an immunosuppression risk in that all 4 of these patients were HIV positive. Surveillance following excision was undertaken for an average of 6 (range 1 to 12) months, during which time 4 patients underwent a repeat biopsy. DISCUSSION Anal dysplasia found in an otherwise asymptomatic population has a prevalence of 2.2%. This finding supports the routine examination of benign anorectal specimens undergoing microscopic examination. Interestingly, the majority of the patients identified had no immunosuppressant risk factors.