Fine needle aspiration of extramedullary myeloid cell tumor in myelodysplastic syndrome. A report of three cases.

BACKGROUND: Soft tissue tumors are rare in myelodysplastic syndrome (MDS), and the role of fine needle aspiration (FNA) cytology in their diagnosis has not been explored. CASES: Two patients with refractory anemia with excess blasts in transformation (RAEB-t) developed soft tissue swellings during the course of the illness. In a third patient, soft tissue swelling was a presenting feature. The swellings in all three cases were diagnosed as extramedullary myeloid cell tumor (EMT) on FNA and showed increased blasts (10-14%), dyspoietic changes, Auer rods and monocytosis. CONCLUSION: Soft tissue tumors appearing in MDS are likely to be EMTs. FNA is therefore particularly valuable in their diagnosis as morphology, cytochemistry, immunophenotyping and flow cytometric analysis of hematopoietic cells are best studied on aspirated material. We suggest that FNA be preferred over excisional biopsy for the diagnosis of soft tissue swellings in MDS.