Reprint requests to Elaine Yuen Phin Lee, Department of Diagnostic Radiology, Block K,Queen Mary, Hospital, 102 Pokfulam Road, Hong Kong
Diagnostic Imaging in Hematology
Article first published online: 28 JUL 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Hematology
Volume 86, Issue 12, pages 1036–1037, December 2011
How to Cite
Lee, E. Y. P., Leung, A. Y.-H., Anthony, M.-P., Loong, F. and Khong, P.-L. (2011), Utility of 18F-FDG PET/CT in identifying terminal ileal myeloid sarcoma in an asymptomatic patient. Am. J. Hematol., 86: 1036–1037. doi: 10.1002/ajh.22077
Conflict of interest: Nothing to report
- Issue published online: 16 NOV 2011
- Article first published online: 28 JUL 2011
- Accepted manuscript online: 9 MAY 2011 09:32AM EST
- Manuscript Accepted: 2 MAY 2011
- Manuscript Revised: 28 APR 2011
- Manuscript Received: 14 APR 2011
A 63-year-old man was presented with bone pain and was found to be anemic and thrombocytopenic. There were circulating myeloblasts with dysplastic neutrophils. Repeated bone marrow aspirations showed marrow necrosis but no histological features to support the diagnosis of acute myeloid leukemia. In the absence of a definitive diagnosis at the time, a combined 18-F fluoro-deoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) was requested to look for extramedullary neoplasms that might be associated with marrow necrosis (Images1 and2).
Studies and case reports have demonstrated the usefulness of 18F-FDG PET in detection, assessment, and follow up of myeloid sarcoma [1–4]. 18F-FDG PET is a useful tool in detecting early MS, in early relapse, before other cross-sectional imaging modalities are able to detect any morphological change or effects of its metabolic activity after treatment. The 18F-FDG uptake of MS is wide, ranging from SUVmax 2.6–9.7 (Images3 and 4) .
Cases of MS involving the gastrointestinal tract are uncommon, comprising only 7% in a biopsy-proven series . Although most cases of MS are clinically undetectable, gastrointestinal MS commonly presents symptomatically as small bowel obstruction, bleeding, perforation, or intussusceptions [6–8]. This patient was completely asymptomatic in the gastrointestinal tract. The 18F-FDG PET/CT finding, however, prompted a colonoscopy, which identified a solitary ulcer with an erythematous base just inside the terminal ileum. A biopsy of this ulcer showed an infiltration of atypical mononuclear cells consistent with blasts and myeloid precursors with eosinophilic granules. An immunohistochemical stain was positive for the myeloid marker, myeloperoxidase; therefore, the findings were compatible with a diagnosis of myeloid sarcoma.
As bone marrow necrosis is a rare presentation of acute myeloid leukemia, the diagnosis was immediately confirmed and consolidated. The patient was subsequently offered aggressive induction chemotherapy. A bone marrow examination was repeated on day 21 after induction chemotherapy; it showed marrow fibrosis with an absence of necrosis. The patient's hemoglobin and platelet count had improved. This case report underscores the importance of a PET/CT scan in the detection of myeloid sarcoma.