Abstract
Niemann-Pick disease is a recessive, autosomal hereditary lysosomal storage disease. Six types of the disease have been identified (NPD types A, B, C, D, E, and F). Clinic of the patient varies depending on the organ in which sphingomyelin accumulates. The diagnosis is generally made during routine diagnostic tests performed in childhood while examining the etiology of hepatosplenomegaly. Supportive treatment is the mostly preferred treatment. However, splenectomy can be performed because of the risk of rupture if hypersplenism and massive splenomegaly develops. In the present article, a 16-year-old male patient with massive splenomegaly and hypersplenism diagnosed with Niemann-Pick disease type-B in childhood is presented due to the fact that it is a rare disease.

Key words: Hypersplenism; Niemann-Pick disease; massive splenomegaly