Role of Morphology in the Diagnosis of an Unsuspected Case of Chediak-Higashi Syndrome: A Case Report.

Chediak-Higashi syndrome (CHS) is a rare multisystem genetic disorder of childhood, caused by a defect in vesicular trafficking, which is an essential process for intracellular transport. This defect results in the formation of giant cytoplasmic granules in various cell types, including white blood cells, melanosomes, and Schwann cells. The presence of giant lysosomal granules in neutrophils and their precursors is a distinct and diagnostic feature of CHS, differentiating it from other childhood immunodeficiency disorders, such as Griscelli syndrome and Hermansky-Pudlak syndrome, which share common characteristics like albinism and increased susceptibility to fatal hemophagocytic lymphohistiocytosis. Diagnosing CHS is challenging for both clinicians and pathologists, requiring a high degree of suspicion. This case emphasizes the critical role of vigilant observation of subtle clinical and pathological features for an accurate diagnosis. We present a rare case of CHS in a six-month-old male child who presented with recurrent episodes of fever and failure to thrive. Physical examination revealed patchy gray hair on the scalp and hypopigmented patches on the lower limbs. Laboratory findings showed pancytopenia, with large, coarse cytoplasmic granules in neutrophils and their precursors on bone marrow examination - a finding diagnostic of CHS. This case highlights the importance of morphological assessment in diagnosing this rare and potentially fatal disorder, enabling early diagnosis and prompt treatment.