Isolated unexplained splenomegaly with or without hepatomegaly, is observed in the majority of patients with NP-C and is the strongest visceral indicator of the disease. When present in combination with other neurological and/or psychiatric symptoms, including vertical supranuclear gaze palsy (VSGP), ataxia and schizophrenia-like symptoms, isolated splenomegaly becomes highly suggestive of NP-C. Isolated unexplained splenomegaly should always lead to the inclusion of NP-C in the differential diagnosis, and hence trigger a search for other symptoms of the disease. Splenomegaly in NP-C ranges from slight to tremendous enlargement, even in young children. Importantly, the degree of splenomegaly does not correlate with neurological manifestations, disease severity or illness stage. Absence of splenomegaly should not lead to the exclusion of NP-C.^[1]