Horseshoe-shaped perianal abscess

Abstract

Perianal pain is common complaint in the emergency department. It has various differential diagnosis including perianal abscess. The diagnosis of perianal abscess is clinical, however in a number of cases, imaging is needed.¹,²

The images correspond to a 29-year-old male patient who presented to the Emergency Department with perianal pain. Physical examination revealed an anal lesion associated with a small area of swelling, without fluctuation or signs of inflammation. Digital rectal examination was unremarkable. Laboratory tests showed leukocytosis and elevated CRP. A pelvic CT scan revealed a large abscess with a horseshoe shape. The study was performed before and after intravenous administration of iodinated contrast. Panel A (sagittal CT scan) and Panel B (coronal CT scan), both post-contrast, show the abscess with greater expression on the posterior aspect of the perineum, measuring 4 cm in thickness. Panels C and D (axial CT scan), without intravenous contrast and after its administration via portal venous infusion. The patient underwent a modified Hanley procedure and was discharged on the first postoperative day. This is a clinical case that exemplifies the high degree of suspicion that should exist even if the physical examination does not reveal the pathology.

A horseshoe perianal abscess is a complex disease that required emergency treatment due to the risk of severe sepsis, hence an early diagnosis is essential.