Atypical Presentation of Hairy Cell Leukemia Masquerading as Isolated Thrombocytopenia: A Diagnostic Odyssey Emphasizing Vigilance in Healthcare

Hairy Cell Leukemia (HCL) is a rare chronic B-cell lymphoproliferative neoplasm typically presenting with splenomegaly and pancytopenia. This case report discusses the atypical presentation of HCL in a 29-year-old male who exhibited isolated thrombocytopenia without classical symptoms leading to initial misdiagnosis as dengue delayed recognition until immunophenotyping revealed monotypic B cell markers characteristic of HCL. This case underscores the challenges in diagnosing atypical HCL emphasizing the importance of vigilance, detailed morphological assessment and advanced diagnostic tools for early detection and contributes to awareness of non-classical HCL presentations.