Failure to detect extramedullary hematopoiesis during bone-marrow imaging with indium-111 or technetium-99m sulfur colloid.

A patient with postpolycythemic myeloid metaplasia developed an enlarging abdominal mass documented on TCT scanning. To distinguish between lymphoma and extramedullary hematopoiesis, marrow elements were imaged with indium-111 chloride and technetium-99m sulfur colloid. Because the mass failed to accumulate either tracer, a presumptive diagnosis of lymphoma was made and exploratory surgery was performed. The excised mass was found to consist of enlarged lymph nodes containing extramedullary hematopoiesis. Caution should be exercised in the use of In-111 or Tc-99m SC bone-marrow scans to diagnose sites of extramedullary hematopoiesis.