TY - JOUR AU - Ramesh, Shruti Neelamegam; Padhi, Somanath; Adhya, Amit K.; Panigrahi, Ashutosh; Das, Prabodha K.; Patra, Susama TI - Hairy Cell Leukemia: Morphological and Immunophenotypic Characteristics of Seven Cases and Cyclin D1 Expression SN - 0971-5851 SN - 0975-2129 PY - 2021 JO - Indian J Med Paediatr Oncol JF - Indian Journal of Medical and Paediatric Oncology LA - EN VL - 42 IS - 06 SP - 595 EP - 598 DA - 2021/12/30 KW - hairy cell leukemia KW - trephine biopsy KW - translocation KW - therapy AB - Aberrant immunophenotypic expression in hairy cell leukemia (HCL), both at medullary and extramedullary sites, is not uncommonly reported in literature. Cyclin D1 positivity in HCL may mimic mantle cell lymphoma (MCL) morphologically, especially in the presence of aberrant CD5 immunopositivity, requiring BRAFV600E mutation and/or CCND1 gene testing for confirmation. Here, we describe seven cases of HCL with clinicomorphological and immunophenotypic characteristics with an emphasis on cyclin D1 expression using immunohistochemistry (IHC) with a brief comprehensive literature review. We suggest that cyclin D1 positive HCL may be a distinct subtype which requires further immunophenotypic and molecular characterization for accurate diagnosis and planning of definitive therapy. PB - Thieme Medical and Scientific Publishers Pvt. Ltd. DO - 10.1055/s-0041-1736431 UR - http://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0041-1736431 ER -