Cutaneous Presentation Mimicking Tuberculosis as an Initial Indicator of Hairy Cell Leukemia: A Case Report.

Hairy cell leukemia (HCL) is a rare and slow-progressing lymphoid disorder commonly presenting with splenomegaly and cytopenias. The diagnosis can be challenging due to its nonspecific clinical presentation, frequently resembling other diseases. We report the case of a 48-year-old male patient, whose initial diagnostic hypotheses included cutaneous tuberculosis and reactive arthritis, but the diagnosis was confirmed as HCL after further investigation, including flow cytometry. Treatment with purine analogs led to remission and improved the patient's outcome. This case highlights the complexity of diagnosing HCL, particularly in atypical presentations, and emphasizes the importance of a multidisciplinary approach involving clinical, laboratory, and advanced diagnostic techniques. Despite its rarity, HCL should be considered in patients with unexplained cytopenias and splenomegaly.