Paroxysmal nocturnal haemoglobinuria (PNH) manifesting on CT as a pathologic segment of small bowel.

Paroxysmal nocturnal haemoglobinuria, a rare, acquired, life-threatening disease of the blood, is characterised by a triad of haemolysis previously believed to occur mainly at night, bone marrow dysfunction, and thrombophilia. Paroxysmal nocturnal haemoglobinuria is customarily regarded to manifest clinically as haemolytic anaemia and haemoglobinuria experienced as reddened urine in the morning, pancytopenia, and thrombosis. We describe a case in which an abnormal segment of small bowel as visualised on computed tomography was the principal sign of the disease process on presentation.