Nonleukemic granulocytic sarcoma presenting as intussusception of small bowel

Granulocytic sarcoma (GS) is defined as a localized tumor mass composed of myeloid blasts and/or immature myeloid cells in an extramedullary site. Usually, GS occurs concomitantly with or after acute myelogenous leukemia (AML), myeloproliferative disorder, or myelodysplastic syndrome. In rare cases, it occurs as a "preleukemic" condition and may precede the onset of AML, which occurs within several months if the patient is not treated with AML-type systemic chemotherapy. Recently, we discovered one case of nonleukemic GS in the small intestine incidentally when intussusception was suspected. The patient visited the emergency department, in October 2006, with symptoms of small-bowel obstruction. Intussusception due to a small-intestinal mass was suspected after evaluation, and small-intestine segmental resection was performed. The patient had no previous history of leukemia, and immunohistochemical staining was used to diagnose GS. Bone-marrow biopsy performed subsequently revealed no lesions that could be suspected as leukemia. The patient received three cycles of chemotherapy, applied as for AML (cytosine arabinoside and anthracycline), and is currently, as of October 29, 2007, showing no other marked indisposition; he has been disease-free for 12 months.