CT of inguinal canal lipomas and fat-containing inguinal hernias.

Inguinal canal lipomas are a frequent, often unrecognised finding on abdominopelvic CT. Commonly referred to as spermatic cord or round ligament lipomas, they are not true tumours of fat but are extrusions of extraperitoneal fat into the inguinal canal. Their fat content and shared location in the inguinal canal result in confusion with fat-containing inguinal hernias with which they often coexist. As laparoscopic herniorrhaphies proliferate, greater awareness of the condition by radiologists is needed to provide accurate preoperative information. This pictorial essay highlights the differentiating diagnostic features of inguinal canal lipomas and fat-containing inguinal hernias.