بایگانی برچسب برای: Histiocytic

Histiocytic.Disorders.[taliem.ir]

Histiocytic Disorders

The “histiocytoses” have been a collective description of tissue proliferations of the hematopoietic-derived cells that compose both the monocyte-macrophage and the dendritic cell families. Our understanding of histiocytic disorders has evolved from the frst classifcation published by the Histiocyte Society (HS) Working Group in 1987 that included disorders of Langerhans cells (LC), non-Langerhans cell related, and the malignant histiocytoses (MH) . A more contemporary classifcation was laid out in 1997 by the World Health Organization (WHO) Committee on Histiocytic/Reticulum Cell Proliferations and the Histiocyte Society Reclassifcation Working Group (Table 1.1) . These classifcations were based on biologic behavior and histopathology, including dendritic cell related (e.g., Langerhans cell histiocytosis (LCH), juvenile xanthogranuloma (JXG) family), macrophage related (e.g., hemophagocytic syndromes, Rosai-Dorfman disease (RDD)), and malignant disorders, typically grouped by their most common morphologic/immunophenotypic counterpart. The histology together with the clinical features and stage of involvement had resulted in a unifying clinicopathologic diagnosis in most cases . However, the feld of histiocytic disorders is now within an era of “molecular enlightenment.” New molecular data are emerging that support the theory that LCH and Erdheim-Chester disease (ECD) (and possibly also systemic JXG lesions with gain of function mutations) are best classifed as inflammatory myeloid neoplasms .