ABSTRACT
BACKGROUND: Langerhans cell precursors are considered to be identical to their mature counterparts except for the lack of Birbeck granules. Proliferations composed of such histiocytes appear to be uncommon. METHODS: Standard immunophenotypic, molecular genetic, and DNA content studies were used to characterize various hematopoietic disorders, including a proliferation of precursor Langerhans cells, which arose sequentially in a patient. RESULTS: The patient studied initially had a low-grade, B-cell, non-Hodgkin lymphoma and subsequently had an unusual histiocytic proliferation (precursor Langerhans cell histiocytosis) in cutaneous and lymph node sites. The patient eventually died of acute myelogenous leukemia (FAB, M5). CONCLUSIONS: A larger series is required to determine the significance of the precursor Langerhans cell phenotype, particularly with respect to the development of acute myelogenous leukemia.
