Perianal venous thrombosis

**Definition:** Extremely painful cherry like lesions under the perianal skin containing clotted blood have been attributed to rupture of a blood vessel with haematoma. However, histology confirmed that these lesions are thrombi lying within the thin-walled vessels of the external anal plexus.

**Inclusions:** - Perianal haematoma (nontraumatic) - perianal thrombosis