# Hairy Cell Leukemia and Its Mimics: A Case-Based Exploration of Diagnostic Complexity

## TL;DR

This paper explores the diagnostic challenges of hairy cell leukemia and similar conditions using case-based analysis and modern diagnostic techniques.

## Contribution

The paper introduces case-based insights into the diagnostic complexities of HCL variants and highlights emerging molecular markers for accurate diagnosis.

## Key findings

- HCL variants lack BRAF mutations and show atypical profiles, complicating diagnosis.
- Integrated diagnostic methods, including flow cytometry and molecular markers, improve diagnostic accuracy.
- Case reports emphasize the importance of combining morphological, immunophenotypic, and molecular data.

## Abstract

Hairy cell leukemia (HCL) is a rare but well-characterized B-cell malignancy with distinct immunophenotypic and genetic features. Advances in molecular diagnostics, particularly the identification of the BRAF V600E mutation, have significantly enhanced diagnostic precision and informed targeted treatment strategies. However, the HCL variant and other HCL-like syndromes continue to present substantial diagnostic challenges due to their absence of BRAF mutations, atypical immunophenotypic profiles, and divergent clinical courses. This case report provides an overview of the morphological, immunophenotypic, molecular, and histopathological features of HCL, as well as its differential diagnoses, with a focus on the utility of flow cytometry and emerging molecular diagnostic markers. To underscore the practical implications of these diagnostic complexities, we present a case report that reinforces the challenges in distinguishing HCL from its mimics and highlights the role of contemporary integrated diagnostic methodologies.