Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ INTRODUCTION ++ 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 Graphic Jump LocationTABLE 37–1CLASSIFICATION OF HISTIOCYTIC DISORDERSView Table|Favorite Table|Download (.pdf) TABLE 37–1 CLASSIFICATION OF HISTIOCYTIC DISORDERS Disorders of varying biologic behavior, lacking cytologic atypia Dendritic-cell related* Langerhans cell histiocytosis Juvenile xanthogranuloma Erdheim-Chester disease Monocyte-macrophage related Hemophagocytic lymphohistiocytosis Familial and/or with identified dysfunctional gene mutation Secondary hemophagocytic syndromes Infection associated Malignancy associated Autoimmune associated Other Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) Solitary histiocytoma of macrophage phenotype Malignant disorders Dendritic-cell related Histiocytic sarcoma Monocyte-macrophage related Leukemias Acute monocytic and, acute myelomonocytic (see Chap. 46) Chronic myelomonocytic leukemias (see Chap. 47) *Here Langerhans cell histiocytosis is placed in relationship to monocyte-derived dendritic cell disorders. There is evidence that the dendritic cell proliferation in Langerhans cell histiocytosis is clonal and, thus, it is pathologically a neoplasm.Source: Williams Hematology, 8th ed, Chap. 72, Table 72–2, p. 1048. ++Table Graphic Jump LocationTABLE 37–2DISTINCTIONS IN ANTIBODIES TO CELL-SURFACE EPITOPES AND MICROSCOPIC FINDINGS AMONG THE HISTIOCYTIC DISEASESView Table|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 - - - - + Source: Williams Hematology, 8th ed, Chap. 72, Table 72–1, p. 1048. ++ CLONAL HISTIOCYTOSES ++ Langerhans Cell Histiocytosis ++ Definition and History ++ 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 ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more!