Katarzyna Muras-Szwedziak, Jacek Kasznicki, Olga Wegner, Maciej Wójcik, Olga Wojtyczka
BACKGROUND Gaucher disease (GD) is the most common lysosomal storage disorder caused by glucocerebrosidase deficiency. Type 1 GD (GD1) often presents with nonspecific manifestations, including splenomegaly, cytopenias, growth impairment, and skeletal involvement, leading to delayed diagnosis and irreversible complications. This report highlights the delayed diagnosis of GD1 in a patient with longstanding mild manifestations and emphasizes the importance of considering GD in patients with unexplained cytopenias and splenomegaly. CASE REPORT We describe a male patient with GD1 whose first manifestations appeared in infancy and included splenomegaly. During childhood, persistent cytopenias, hepatosplenomegaly, and growth deceleration were observed; however, the diagnosis remained unrecognized. At age 14, the patient developed severe skeletal pain accompanied by fever, prompting further diagnostic evaluation. Imaging studies revealed bone marrow abnormalities, and bone biopsy demonstrated foamy macrophages but did not establish a definitive diagnosis. At age 15, GD1 was suspected and subsequently confirmed by enzymatic testing, biomarker assessment, and genetic analysis. Enzyme replacement therapy with imiglucerase resulted in clinical improvement, reduced organomegaly, and stabilization of laboratory parameters. The patient subsequently underwent a structured transition from pediatric to adult care without treatment interruption. CONCLUSIONS GD should be considered in patients with unexplained splenomegaly and persistent cytopenias, even when early manifestations are mild and nonspecific. Early recognition and disease-specific diagnostic testing may reduce diagnostic delay, facilitate timely treatment initiation, and help prevent irreversible complications. This case also highlights the importance of a structured transition from pediatric to adult care in maintaining long-term treatment continuity.