[Successful treatment with enzyme replacement therapy for pelvic fragile fracture in an elderly case of type I Gaucher's disease].

A 76-year-old male with lower-limb weakness was admitted to our hospital where thrombocytopenia and anemia were noticed. CT showed massive splenomegaly and multiple nodules inside the spleen. Bone marrow examination showed an increase of macrophages with large cytoplasm. Suspected of splenic lymphoma, the patient underwent splenectomy. Spleen specimens were histologically analyzed and suggested the probability of Gaucher's disease (GD). Leukocyte glucocerebrosidase (GBA) enzyme activity had decreased to 1.25 nmol/mg, and mutation analysis of GBA revealed two missense variants, p.D448H (D409H), p.L483P (L444P), which confirmed the diagnosis of type I GD. Fourteen months after splenectomy, he developed right buttock pain, and pelvic magnetic resonance imaging showed a fragile right pubic and pelvic fracture. We initiated injection of imiglucerase as enzyme replacement therapy (ERT) and administered bisphosphonate. His symptoms gradually improved without surgical treatment. In addition, thrombocytopenia and anemia also improved, and angiotensin-converting enzyme levels decreased. Type I GD should be considered a differential diagnosis of giant splenomegaly and thrombocytopenia, even in the elderly. ERT or substrate reduction therapy should be administrated to GD patients, while paying attention to the development of bone lesions.