To analyze the CT and MR imaging characteristics of the subcutaneous and organ lesions of uvenile xanthogranuloma (JXG) in children.

The CT and MR images of the head, chest, abdomen and subcutaneous soft tissue of 11 patients (6 females and 5 males, aged 2 months-12 years old, median age 8 months old) with JXG from 2006 to 2018 were collected and retrospectively analyzed. Eight patients underwent CT scan and/or contrast-enhanced CT scan, and 7 patients underwent MRI and/or MRI and contrast-enhancement MRI.

In 11 cases of JXG, 5 cases were classified as simple skin type, involving the skin and deep soft tissue in the right posterior neck, the right frontal and parietal parts of the head, the nose root, and the fat layer and the deep muscle in the extremities. The lesions were the subcutaneous soft tissue nodules or mass showing isodensity on CT or high signal on T₂WI. And the other 6 cases were classified as systemic type whose lesions involved one or more than one part except the skin. In the 6 cases, 3 cases involved the central nervous system, including the pituitary gland, cerebral hemisphere, cerebellum, brain stem, basal ganglia, thalamus, optic chiasma and spinal cord. The lesions of the pituitary gland were manifested as pituitary enlargement, thickening of the pituitary stalk, and disappearance of high signal on T₁WI in the neurohypophysis. The brain parenchyma, the spinal cord and the optic chiasma showed multiple flake or nodular masses, which were iso/low signal on T₁WI, low/high signal on T₂WI, diffusion restricted, and enhanced markedly. Two cases involved lung tissue, and their lesions showed diffuse or scattered multiple cloudy shadow, reticular opacity, strip and small nodule shadow on chest CT. There was pleural effusion in one case. Two cases involved the livers and 2 cases involved the kidneys, showing multiple nodules with low signal on T₂WI and slight enhancement. One case involving the pancreas showed a low density in the head of the pancreas and slight enhancement on CT. One case involving the greater omentum, chest wall and peritoneum showed thickening of the corresponding tissues on CT.

Subcutaneous and systemic lesions of JXG show some characteristics on CT and MRI images. The main manifestations are single or multiple nodulars, which are diffusely distributed and vary in size in subcutaneous soft tissue and various organs. The combination of imaging appearances, clinical manifestations and biopsy has important clinical significance for the correct diagnosis and evaluation of JXG.

Granuloma; Tomography, X-ray computed; Magnetic resonance imaging