Spontaneous presacral haematoma mimicking rectal malignancy--an unusual consequence of anticoagulation.

An 81-year-old man on warfarin was admitted to hospital after 3 days of constipation, straining and mild rectal bleeding. A large, boggy mass was felt posteriorly on direct rectal examination. Investigations revealed a normocytic anaemia and a supratherapeutic international normalised ratio (INR). Fearing a late presentation of malignancy, an urgent CT of abdomen and pelvis was arranged which showed a homogeneous mass arising between the sacrum and the rectum. Given the anaemia in the presence of anticoagulation, and subsequent widespread perineal and scrotal ecchymosis, the patient was diagnosed with atraumatic presacral haematoma. Following resuscitation, the patient was managed non-operatively and was discharged several days later following stabilisation of the haemoglobin and INR. At 3 months, he had complete clinical and radiological resolution of this haematoma.