Rectus sheath haematoma in a canoeist.

A 26-year-old male canoeist was referred with a 10-day history of abdominal pain, and a palpable mass in the left upper quadrant. No history of direct trauma was given. He was not taking any medication, and malignancy and inflammatory conditions were considered in the differential diagnosis. Ultrasonographic scan identified a mass originating in the rectus abdominis sheath. Ultrasonographically guided aspiration yielded some partially clotted blood, confirming the clinical diagnosis of rectus sheath haematoma. After conservative treatment, the patient resumed training, and is fully asymptomatic 1 year after discharge.