Polyps and polypoid lesions of the anus

Anal polyps are a relatively rare and neglected part of pathology practice. Similar to other parts of the gastrointestinal tract, anal polyps are predominantly epithelial in origin, but mesenchymal lesions do occur. The aetiology of anal polyps is diverse and includes infectious, reactive, developmental and neoplastic conditions. Thus an awareness of the clinical scenario can be very informative in difficult cases. Diagnostic pitfalls are perhaps more common than is generally realized and misdiagnosis can have important management and social implications. Herein, we discuss the most common and interesting anal polyps and polypoid lesions with a particular focus on diagnostic pitfalls. Careful attention to the clinical scenario and histological features, along with judicious use of immunohistochemistry will resolve most diagnostic dilemmas.