NCI Definition: An indolent chronic B-cell leukemia resembling classic hairy cell leukemia but shows variant cytologic, hematologic, and immunophenotypic features and is resistant to the conventional therapy applied to hairy cell leukemia. Biologically, it is not related to hairy cell leukemia. [1]

Hairy cell leukemia variants most frequently harbor alterations in TP53, NOTCH2, KDM6A, and BTK [2].

Most Commonly Altered Genes in Hairy Cell Leukemia Variant

TP53 c.217-c.1178 Missense, TP53 V173M, TP53 Mutation, TP53 Missense, and TP53 Exon 5 Mutation are the most common alterations in hairy cell leukemia variant [2].

Top Alterations in Hairy Cell Leukemia Variant

Disease Details

Hairy Cell Leukemia-Variant, Prolymphocytic Variant of Hairy Cell Leukemia, HCL-V
Splenic B-Cell Lymphoma/Leukemia, Unclassifiable
OncoTree Name
Hairy Cell Leukemia-Variant
OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 8. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.