Granulocytic sarcoma of the small intestine preceding or as the presenting feature of acute myelogenous leukemia with chromosome 16 abnormalities has been observed in at least 4 patients. We report the case of a patient initially diagnosed with eosinophilic gastroenteritis, responding to corticosteroid treatment for 21 months and eventually transforming into an acute myelogenous leukemia with eosinophilia (M4Eo variant).