Niemann-Pick disease type B: HRCT assessment of pulmonary involvement.

Objective: To analyze HRCT findings in patients with Niemann-Pick disease (NPD) type B, in order to determine the frequency of HRCT patterns and their distribution in the lung parenchyma, as well as the most common clinical characteristics.

Methods: We studied 13 patients (3 males and 10 females) aged 5 to 56 years. HRCT images were independently evaluated by two observers, and disagreements were resolved by consensus. The inclusion criteria were presence of abnormal HRCT findings and diagnosis of NPD type B confirmed by histopathological examination of a bone marrow, lung, or liver biopsy specimen.

Results: The most common clinical findings were hepatosplenomegaly and mild to moderate dyspnea. The most common HRCT patterns were smooth interlobular septal thickening and ground-glass opacities, which were both present in all patients. Intralobular lines were present in 12 patients (92.3%). A crazy-paving pattern was observed in 5 patients (38.4%), and areas of air trapping were identified in only 1 case (7.6%). Pulmonary involvement was bilateral in all cases, with the most affected area being the lower lung zone.

Conclusions: Smooth interlobular septal thickening, with or without associated ground-glass opacities, in patients with hepatosplenomegaly is the most common finding in NPD type B.