Arthritis in pediatric patients presents a range of diagnostic challenges, including conditions such as septic arthritis, inflammatory arthritis, idiopathic chondrolysis, toxic synovitis, Lyme arthritis, and hemophilic arthritis. These conditions often share overlapping clinical and imaging features, complicating accurate diagnosis. However, key differences in clinical presentation and imaging findings can aid in differentiation. For instance, both septic arthritis and inflammatory arthritis may present with joint pain, swelling, and limited range of motion, with ultrasound commonly revealing joint effusion. Septic arthritis is typically characterized by an acute onset, high fever, elevated white blood cell (WBC) count, and significantly increased inflammatory markers. MRI findings often include complex joint effusions, synovial thickening, and periarticular bone marrow edema, with advanced cases showing periarticular myositis or pyomyositis and osteomyelitis involvement. In contrast, inflammatory arthritis usually presents with gradual onset, low-grade fever, and minimal WBC elevation, with MRI findings of symmetric or asymmetric synovial thickening, synovial enhancement, pannus formation, and mild to none surrounding muscular or bony involvement. This educational exhibit aims to review the epidemiology of pediatric arthritis, including septic arthritis, inflammatory arthritis, idiopathic chondrolysis, toxic synovitis, Lyme arthritis, and hemophilic arthritis. It will discuss appropriate imaging protocols and highlight key clinical and imaging features that distinguish each arthritis, enhancing diagnostic accuracy and optimizing patient management. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Grimm Elizabeth, Law Emily, Luo Yu

Keywords: Septic Arthritis, MR, Infection

Lumps and bumps in the pediatric hands and feet are frequently encountered in pediatric imaging. While certain lesions demonstrate characteristic imaging features that allow for confident diagnosis, others present with nonspecific findings and require tissue sampling for definitive diagnosis. After reviewing this case and imaging-based discussion of benign and malignant lesions in the pediatric hands and feet, viewers will be able to: 1. Identify common benign and malignant bone and soft tissue lesions of the hands and feet in children. 2. Recognize imaging features of aggressive lesions that warrant biopsy. 3. Diagnose characteristic lesions based on their imaging appearance. Lesions discussed in this exhibit include: 1. Aggressive Bone Lesions: Osteomyelitis, undifferentiated sarcoma. 2. Benign Bone Lesions: Aneurysmal bone cyst, simple bone cyst, giant cell reparative granuloma, giant cell tumor, hemangioma, enchondroma, Trevor’s disease (dysplasia epiphysealis hemimelica), osteoid osteoma, osteoblastoma, abscess. 3. Malignant Soft Tissue Tumors: Infantile fibrosarcoma, rhabdomyosarcoma, synovial sarcoma, other soft tissue sarcomas, including malignant peripheral nerve sheath tumor (MPNST). 4. Benign Soft Tissue Lesions: Ganglion cyst, desmoid tumor, giant cell tumor of tendon sheath, infantile digital fibromatosis, myofibroma, nerve sheath tumor, dermatofibroma, granuloma annulare. 5. Calcified Lesions: Synovial sarcoma, soft tissue chondroma, venous malformation, chondro-osseous lipoma. 6. Vascular Lesions: Arteriovenous malformation (AVM), venous malformation, lymphatic malformation, hemangioma, Kaposiform hemangioendothelioma. 7. Fatty lesions: Lipoma, fibrolipomatous hamartoma of nerve. Read More

Meeting name: IPR 2026 Congress , 2026

Authors: Law Emily, Crane Gabriella, Luo Yu

Keywords: Tumor, Musculoskeletal, Malignancy

Trichorhinophalangeal syndrome type I (TRPS I) is a rare autosomal dominant skeletal dysplasia characterized by distinctive craniofacial (pear-shaped nose, long philtrum, thin upper lip, prominent ears, sparse, slow-growing hair, and dystrophic nails) and skeletal abnormalities (short stature, brachydactyly, cone-shaped epiphyses, and hip dysplasia). When bilateral Legg-Calvé-Perthes disease (LCPD) occurs, the femoral head changes typically manifest symmetrically and simultaneously, often suggesting an underlying skeletal dysplasia. We present an unusual case of an 11-year-old male with bilateral asymmetric “Perthes disease,” with the left hip in the late or healing phase and the right hip in the early phase. The patient had no prior history or treatment for left-sided LCPD. He underwent right hip core decompression before genetic consultation. On physical examination, he exhibited relatively sparse hair, short stature, a pear-shaped nose with underdeveloped alae, and shortened digits. Recognition of these characteristic craniofacial features prompted the geneticist to order a skeletal survey and TRPS1 panel. Skeletal survey demonstrated bilateral symmetric cone-shaped epiphyses in the proximal phalanges of both feet and the middle and distal phalanges of the hands, coxa magna and breva of the left hip, and flattening and sclerosis of the right proximal femoral epiphysis. Additional findings included tonguing of multiple thoracic vertebrae, short pedicles of the lower lumbar spine, and decreased interpedicular distance at L5. Differential diagnoses include TRPS, pseudoachondroplasia, multiple epiphyseal dysplasia, or spondyloepiphyseal dysplasia. Molecular testing identified a heterozygous pathogenic variant in TRPS1 (c.1630C>T, p.Arg544*), confirming the diagnosis of TRPS I. This case illustrates that temporally asymmetric, bilateral Perthes-like changes may obscure an underlying skeletal dysplasia and the importance of recognizing characteristic craniofacial features to guide timely genetic evaluation and management. Read More

Meeting name: IPR 2026 Congress , 2026

Authors: Law Emily, Sarma Asha, Crane Gabriella, Luo Yu

Keywords: Skeletal, Genetics, Dysplasia