The application of x-ray, computed tomography, and magnetic resonance imaging on 22 pediatric Langerhans cell histiocytosis patients with long bone involvement: A retrospective analysis

Abstract

The studies focusing on x-ray, computed tomography (CT), and magnetic resonance imaging (MRI) in pediatric Langerhans cell histiocytosis (LCH) patients were still rare. Therefore, we aimed to evaluate the application of x-ray, CT, and MRI in pediatric LCH patients with long bone involvement.Total 22 pediatric LCH patients were included in this study. The diagnosis of LCH was confirmed by pathological examination. All patients were followed up for 3 years. X-ray, CT, or MRI was performed and the results were recorded for further analyses.Among 22 pediatric patients, x-ray (n = 20), CT (n = 18), or MRI (n = 12) were used to scan the lesion on long bones affected by LCH. Femurs (n = 13, 38.24%), tibia (n = 11, 32.35%), humerus (n = 5, 14.71%), and radius (n = 4, 11.76%) were the most frequently affected anatomic sites. Ovoid or round radiolucent lesions, aggressive periosteal reaction, and swelling of surrounding soft tissues were characteristic image of long bones on x-ray, CT, and MRI in pediatric LCH.Femurs, tibia, humerus, and radius were the most commonly affected long bones of pediatric LCH. The application of x-ray, CT, and MRI on long bones could help with the diagnosis of pediatric LCH.

Figure 1

T2WI, T1WI, and STIR MR sequences of the right tibia of an 8-year-old boy with Langerhans cell histiocytosis. The ovoid lesion with isointense and hypointense signals on T1 sequence (A) and hyperintense signals on T2 sequence (B) were detected in the lower 1/3 of the medullary cavity of the right tibia. The lesion had a sclerotic margin, which showed hyperintense signals on STIR sequence (C). There was also a layered periosteal reaction (D). MR = magnetic resonance, STIR = short time inversion recovery sequences.

Figure 2

X-ray (A), CT (B), and MRI STIR sequence (C) of left femur from a 6-year-old boy with Langerhans cell histiocytosis. Destructive oval lesions were observed in the middle left femoral diaphysis on x-ray, CT, and STIR sequence. These lesions were associated with thickly lamellated periosteal reaction and soft tissue swelling. The STIR image showed extensive high intense signal in the medullary cavity: CT (D) and MRI STIR sequence (E) of a 2-year-old boy with Langerhans cell histiocytosis. At the middle of the right tibial diaphysis, lytic bone destruction associated with periosteal reaction and soft tissue mass was observed. CT = computed tomography, MR = magnetic resonance, STIR = short time inversion recovery sequences.

Figure 3

X-ray (A), CT (B and C), pathological (D), and histological (E) images right ulna from a 4-year-old boy with Langerhans cell histiocytosis. Bone destruction associated with mild periosteal reaction on right proximal ulna was observed (A and B). After 25 months of chemotherapy, the bone density of proximal ulna and the cortical bone thickness became normal (C). CT = computed tomography.