Challenges in the Histopathologic Diagnosis of Histiocytic Neoplasms

J Natl Compr Canc Netw. 2021 Nov;19(11):1305-1311. doi: 10.6004/jnccn.2021.7098.ABSTRACTHistiocytic neoplasms, including Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), and Rosai-Dorfman disease (RDD), present a diagnostic challenge due to nonspecific fibroinflammatory infiltrates and a diverse clinical presentation. The pathologist can play a key role in classification of these disorders through multidisciplinary collaboration and correlation of pathologic features with clinical and radiologic findings. The histopathologic differential diagnosis is broad, requiring knowledge of the possible diagnoses at each specific anatomic site, and a careful assessment to exclude other inflammatory and neoplastic disorders. An immunohistochemistry panel including CD163, CD1a, langerin, S100, Factor XIIIa, OCT2, and BRAF V600E can provide definitive diagnosis in LCH and RDD, whereas ECD requires classic clinical features as well as confirmation of an activating MAPK pathway mutation by genetic studies.PMID:34781270 | DOI:10.6004/jnccn.2021.7098
Source: Journal of the National Comprehensive Cancer Network : JNCCN - Category: Cancer & Oncology Authors: Source Type: research