Contrast-enhanced ultrasonography in nodular splenomegaly associated with type B Niemann-Pick disease: an atypical hemangioma enhancement pattern.

BACKGROUND

Niemann-Pick disease (NPD) types A and B are lipid storage disorders. NPD type A is a fatal disorder of infancy. Type B is a non-neuronopathic form observed in children and adults. It is associated with enlargement of the liver, spleen, or both, and nodular splenomegaly may be detected with ultrasound.

METHODS

A 21-year-old female was admitted to the Emergency Room with fever, pharyngitis, and left upper quadrant abdominal pain. Labwork revealed anemia, thrombocytopenia, increased levels of AST, ALT, GGT, AF, LDH, triglycerides, and total cholesterol and low levels of HDL-cholesterol. PCR blood assays for CMV and EBV were both negative. Chest X-ray was unremarkable. Transabdominal B-mode ultrasound (US) revealed splenomegaly (long axis: >22 cm), an irregular subcapsular hypoechoic lesion in the superior pole that was consistent with splenic infarction, and multiple round highly echogenic nodes measuring 1-5 cm in diameter. Contrast-enhanced ultrasonography (CEUS) was performed using SonoVue(®) (Bracco).

RESULTS

The presence of a splenic infarction was confirmed. The nodular lesions showed arterial-phase enhancement with late parenchymal phase wash-out. (18)F-FDG-PET revealed splenic nodular uptake. Primary splenic lymphoma was suspected, and the patient underwent open splenectomy. The diagnosis was type B NPD with splenic hemangiomas.

CONCLUSIONS

CEUS confirmed the diagnosis and extent of splenic infarction, but the nodular atypical enhancement pattern together with nodular (18)F-FDG-PET uptake was misleading, suggesting as it did lymphoproliferative involvement of the spleen.