Uncommon histiocytic disorders: The non‐Langerhans cell histiocytoses

Top Cited Papers
Publisher Website
Google Scholar
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.

This publication has 37 references indexed in Scilit: