Histiocytic and Dendritic Cell Neoplasms

Abstract

Histiocytic and dendritic cell neoplasms are very rare, belonging to a group that share morphologic, immunophenotypic, and ultrastructural characteristics of mature histiocytic/dendritic neoplasms. Histiocytic and dendritic cell neoplasms may arise de novo or in association with B-cell, T-cell, or myeloid neoplasms. Recent molecular findings, particularly the discoveries of the mutations in the RAS-RAF-MEK-ERK pathway, have greatly advanced the diagnosis and treatment options. Histiocytic and dendritic cell neoplasms may closely resemble each other, non-hematopoietic neoplasms, and even reactive processes. Therefore, it is essential to understand the clinicopathologic characteristics, differential diagnoses, and pitfalls of each entity.

Keywords: Disseminated juvenile xanthogranuloma; Erdheim-Chester disease; Follicular dendritic cell sarcoma; Histiocytic sarcoma; Indeterminate dendritic cell tumor; Interdigitating dendritic cell sarcoma; Langerhans cell histiocytosis.