The terms histiocyte and macrophage are synonyms for the mature cell of the monocyte-macrophage system. The latter is the preferred term in discussions of cell biology and immunology, but the former term continues to be used by pathologists and in textbooks for diseases of macrophages because of its entrenchment in the medical literature.
A classification of the histiocytoses most relevant to hematologists is shown in Table 37–1. They have been classified based on whether they are monocyte-derived dendritic-cell-related, monocytes-macrophage-related, or neoplastic transformations of dendritic-cells or macrophages.
Distinctions among the diseases of macrophages are made based on clinical findings, histopathology, immunophenotyping of surface antigen, cytochemistry, and cytogenetic or genetic features (Table 37–2).
TABLE 37–1CLASSIFICATION OF HISTIOCYTIC DISORDERS |Favorite Table|Download (.pdf) TABLE 37–1 CLASSIFICATION OF HISTIOCYTIC DISORDERS
Disorders of varying biologic behavior, lacking cytologic atypia
Langerhans cell histiocytosis
Familial and/or with identified dysfunctional gene mutation
Secondary hemophagocytic syndromes
Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)
Solitary histiocytoma of macrophage phenotype
Acute monocytic and, acute myelomonocytic (see Chap. 46)
Chronic myelomonocytic leukemias (see Chap. 47)
TABLE 37–2DISTINCTIONS IN ANTIBODIES TO CELL-SURFACE EPITOPES AND MICROSCOPIC FINDINGS AMONG THE HISTIOCYTIC DISEASES |Favorite Table|Download (.pdf) TABLE 37–2 DISTINCTIONS IN ANTIBODIES TO CELL-SURFACE EPITOPES AND MICROSCOPIC FINDINGS AMONG THE HISTIOCYTIC DISEASES
|Clinical Findings ||Langerhans Cell Histiocytosis ||Malignant Histiocytosis ||Erdheim-Chester Disease/Juvenile Xanthogranuloma ||Hemophagocytic Lymphohistiocytosis ||Rosai-Dorfman Disease |
| ||Langerhans cell ||Interdigitating dendritic cell ||Dermal dendritic cell ||Monocyte- macrophage ||Sinus histiocyte |
|HLH-DR ||++ ||+ ||- ||+ ||+ |
|CD1a ||++ ||- ||- ||- ||- |
|CD14 ||- ||- ||++ ||++ ||++ |
|CD68 ||+/- ||+/- ||++ ||++ ||++ |
|CD163 ||- ||- ||- ||++ ||++ |
|CD 207 (Langerin) ||+++ ||+ ||- ||- ||- |
|Factor XIIIa ||- ||- ||++ ||- ||- |
|Fascin ||- ||++ ||++ ||+/- ||+ |
|Birbeck granules ||+ ||- ||- ||- ||- |
|Hemophagocytosis ||+/- ||- ||- ||+/- ||- |
|Emperipolesis ||- ||- ||- ||- ||+ |
Langerhans Cell Histiocytosis
The term Langerhans cell histiocytosis includes disorders previously called histiocytosis X (eosinophilic granuloma, Letterer-Siwe disease, Hand-Schüller-Christian disease), self-healing histiocytosis, and Langerhans cell granulomatosis.
Langerhans cells are macrophages with irregularly shaped nuclei present in epidermis, mucosa, lymph nodes, thymus, and spleen.
As all macrophages types, they originate in marrow from a multipotential hematopoietic cell.
Identified by unique ...
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