Technetium-99M sulfur colloid scanning and correlative magnetic resonance imaging in patients with hairy cell leukemia and hypocellular bone marrow biopsies after 2-chlorodeoxyadenosine

It has been observed that some patients in complete remission (CR) after 2- chlorodeoxyadenosine (2-CdA) for hairy cell leukemia (HCL) have hypocellula r bone marrow biopsies despite normal peripheral blood cell counts. This di screpancy between bone marrow cellularity and peripheral blood cell counts suggests the possibility of abnormal sites of hematopoiesis. To determine s ites of hematopoieses, 11 radionuclide scans using technetium-99m (Tc-99m) sulfur colloid were performed in eight patients. Although no single, patter n was observed on the Tc-99m sulfur colloid scans, two of the eight patient s, both with virtually aplastic marrows, had multiple areas of increased up take in the distal appendicular skeleton, suggesting abnormal sites of hema topoiesis. The same two patients had magnetic resonance imaging (MRI), whic h confirmed the abnormal sites of hematopoiesis.