Noninvasive approaches to diagnose intrathoracic extramedullary hematopoiesis: 18F-FLT PET/CT and 99mTc-SC SPECT/CT scintigraphy.

Extramedullary hematopoiesis refers to the presence of hematopoietic elements in locations other than the bone marrow medullary space. It occurs as a compensatory mechanism to impaired hematopoiesis resulting from a variety of pathological conditions. Because of the hazards of biopsy of a highly vascular hematopoietic mass, it is desirable to establish the diagnosis noninvasively. We report a case where 18F-fluoro-3'deoxy-L-thymidine PET/CT and 99mTc-SC scintigraphy were used as a noninvasive modality to diagnose extramedullary hematopoiesis.