Histiocytic differentiation in acute monocytic leukemia

ABSTRACT

Myeloid histocytes of dendritic cells (DCs), Langerhans cells (LCs), and macrophages in varied tissues, as leukemic blasts in acute monoblastic and monocytic leukemia (AML-M_5a and M_5b), are derived from monocyte progenitors in bone marrow. Based on DC induction from hematopoietic stem cells, myeloid progenitors, and monocytes, and occasional expressions of histocyte-related antigens (HRAs) in M₅, we presume some M₅ cases share histiocytic phenotypes originally. To clarify the conception, 93 M₅ cases were tested with antibodies for HRAs, CD1a, CD163, S100, fascin, and langerin by immunostaining, and their morphologic characteristics were studied by light and transmission electron microscopy. The study revealed that 23 M₅ cases were positive for two or more kinds of HRAs and shared a serial of histocytic immunophenotype and morphologic features, which were closely associated with M_5b subtype and expression of CD14 in M₅.

KEYWORDS:

• Acute monocytic leukemia
• CD14
• differentiation
• histocyte
• immunophenotype
• morphology

Additional information

Funding

This work was supported by a grant from the National Natural Science Foundation of China (NFSC), No. 81170459.