Acute thrombocytopenia associated with preexisting ulcerative colitis successfully treated with colectomy.

We report a case of successfully treated acute thrombocytopenia associated with preexisting ulcerative colitis (UC). The patient had typical symptoms of UC, and colonoscopy showed pancolitis. During treatment with sulfasalazopyridine (SASP) and steroids, thrombocytopenia was observed. Despite the cessation of drugs, severe thrombocytopenia was noted. Immune thrombocytopenic purpura (ITP) was suspected based on a normal bone marrow megakaryocyte count, positive autoantibody to platelet membrane antigen, and the absence of splenomegaly. Medical treatment, including increased dosage of steroids, failed to control UC and acute thrombocytopenia in this patient. Moreover, acute severe pancreatitis developed and abdominal computed tomography showed toxic megacolon. Platelet count recovered after urgent total colectomy without splenectomy. When patients with UC develop thrombocytopenia, particularly in the presence of extensive and significant colonic inflammation, a diagnosis of ITP should be considered. In such patients, preexisting UC might be involved in the immunological causal mechanism of ITP. In this situation, colectomy might cure both UC and resistant thrombocytopenia. Steroid-refractory and life-threatening UC complicated by thrombocytopenia presumably caused by ITP is therefore a possible indication for colectomy.