The association between Crohn disease and the myelodysplastic syndromes. Report of 3 cases and review of the literature.

We report 3 patients who developed Crohn disease and myelodysplastic syndrome concurrently and review 9 previously reported cases of this association. Demographic and clinical features, treatment, and outcome are presented from previous reports and our own 3 cases. Of the 12 patients, 8 were men, and the mean age was 68.8 years (range, 28-83 yr). The geographic origin was heterogeneous. Pancytopenia was found in 5 patients, anemia in 5, and bicytopenia in 2. The classification types of myelodysplastic syndrome were variable. The marrow karyotype was reported in 10 patients: it was abnormal in 5, with chromosome 20 abnormalities in 3. Crohn disease and myelodysplasia were diagnosed simultaneously in 5 patients, whereas Crohn disease antedated myelodysplasia in 4 patients (interval, 8 mo-30 yr) and myelodysplasia antedated Crohn disease in 3 patients (interval, 2 mo-4 yr). Signs and symptoms of Crohn disease improved in most patients upon specific medical treatment. However, the outcome of myelodysplastic syndrome was not favorable in 10 of 11 patients in whom it was reported, with 4 deaths due to myelodysplasia-related complications. Notably, the activity of myelodysplasia in 1 of our own patients paralleled the clinical activity of Crohn disease, and hematologic abnormalities of the myelodysplasia resolved upon successful treatment of the Crohn disease, thus strengthening the hypothesis of a pathogenetic link between the disorders. The possibility of myelodysplastic syndrome should be considered in patients with Crohn disease over the age of 50 years who have peripheral blood cytopenias. Likewise, a diagnosis of Crohn disease should be considered in patients with myelodysplastic syndrome who develop gastrointestinal symptoms such as chronic and/or bloody diarrhea. In patients with such an association, the possibility of improvement of the myelodysplasia upon successful therapy of Crohn disease should not be ruled out.