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Uncommon histiocytic disorders: The non-Langerhans cell histiocytoses

Authors

  • Sheila Weitzman MB,

    Corresponding author
    1. Senior Staff Oncologist and Professor of Pediatrics, Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada
    2. Division of Hematology/Oncology, Department of Pediatrics, University of Toronto, Toronto, Canada
    • Division of Hematology/Oncology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
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  • Ronald Jaffe MB, BCh

    1. Professor of Pathology University of Pittsburgh School of Medicine, Marjory K. Harmer Professor of Pediatric Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
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  • Sheila Weitzman is a Senior Staff Oncologist and Professor of Pediatrics; Ronald Jaffe is a Professor of Pathology.

Abstract

Background

Histiocytic disorders are currently identified by their component cells. The non-Langerhans Cell Histiocytoses (non-LCH) are a group of disorders defined by the accumulation of histiocytes that do not meet the phenotypic criteria for the diagnosis of Langerhans cells (LCs). The non-LCH consist of a long list of diverse disorders which have been difficult to categorize. A conceptual way to think of these disorders that make them less confusing and easier to remember is proposed based on immunophenotyping and clinical presentation.

Results

Clinically the non-LCH can be divided into 3 groups, those that predominantly affect skin, those that affect skin but have a major systemic component, and those that primarily involve extracutaneous sites, although skin may be involved. Immunohistochernically many of the non-LCH appear to arise from the same precursor cell namely the dermal dendrocyte. Juvenile Xanthogranuloma (JXG) is the model of the dermal dendrocyte-derived non-LCH. Other non-LCH with differing clinical presentation and occurring at different ages but with an identical immunophenotype appear to form a spectrum of the same disorder, deriving from the same precursor cell at different stages of maturation. They should be considered as members of a JXG family. Non-JXG family members include Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Conclusion

The non-LCH can be classified as JXG family and non-JXG family and subdivided according to fairly clear-cut clinical criteria. Utilization of this type of approach will allow better categorization, easier review of the literature and more accurate therapy decision-making. © 2004 Wiley-Liss, Inc.

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