A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). The mononuclear phagocytic system is part of the organism's immune system.

Histiocytosis is a rare group of conditions that occur when your body makes abnormal (mutant) white blood cells called histiocytes. Normal histiocytes help tune up your body’s defenses against multiple pathogens (like viruses, bacteria, fungi and parasites).

Histiocytosis is a generic name for a group of syndromes characterized by an abnormal increase in the number of certain immune cells called histiocytes. These include monocytes, macrophages, and dendritic cells.

Histiocytes are a type of immune cell that are part of the body’s defense mechanism against infections and foreign substances. They belong to the mononuclear phagocyte system including monocytes in the blood and macrophages in tissues.

The term histiocyte refers to a bone marrow–derived progenitor cell that differentiates, depending on the cytokine and growth factor milieu, into a dendritic antigen presenting cell (Langerhans cell, dermal dendrocyte) or a phagocytic cell (tissue macrophage).

Histiocytes are tissue-resident cells derived from myeloid precursors which develop into dendritic cells (DCs), monocytes, and macrophages as members of the mononuclear phagocyte system. From: Best Practice & Research Clinical Rheumatology, 2020

Histiocyte is an umbrella term that encompasses macrophages and dendritic cells. And from these two lineages, we get a whole spectrum of histiocytic diseases like: These disease entities have different (and sometimes overlapping) clinical appearances and cytologic features. Next week, I’ll highlight a case of one of these conditions!

During normal development, histiocytes arise early in pre-natal life, and many cell populations, notably microglia of the brain, are capable of self-renewal and do not require continual replenishment by hematopoiesis.

2016年6月2日 · We propose herein a revision of the classification of histiocytoses based on histology, phenotype, molecular alterations, and clinical and imaging characteristics.

1994年11月1日 · The term histiocyte refers to cells of either the macrophage or Langerhans cell lineages. The histiocytic disorders are characterized by the proliferation of cells of these lineages.