Idiopathic myelofibrosis associated with ulcerative colitis

A patient with ulcerative colitis (UC) who developed idiopathic myelofibrosis (IM) is reported. The initial diagnosis of UC was established by colonoscopy and large bowel biopsy, performed after a one-month history of abdominal pain and bloody diarrhea. The patient showed a favorable response to prednisone and mesalamine treatment and six months later he developed a new episode of UC, which was successfully controlled with treatment. However, two years later splenomegaly and anemia were observed, with aniso-poikilocytosis, tear-drop cells, immature myeloid precursors in the peripheral blood, and increased serum LDH, arising the suspicion of IM, a diagnosis that was confirmed by bone marrow biopsy. The present case represents a new association of IM with an autoimmune disease and gives support to the hypothesis of a possible immune basis of some IM cases.