Pigmented villonodular synovitis of the flexor hallucis longus tendon: A rare cause of leg pain in a 12-year-old girl.

Pigmented villonodular synovitis is an uncommon benign neoplastic proliferation associated with the synovium, bursa, or tendon sheaths; most commonly occurring in the third to fourth decade of life. It is rare in children and may be painful or painless. Magnetic resonance imaging is the diagnostic study of choice. In this report, the radiologic, ultrasound, and magnetic resonance imaging findings of pigmented villonodular synovitis of the flexor hallucis longus in a 12-year-old girl are discussed. We briefly review the surgical findings as well. To our knowledge, this is the first case report that simultaneously synthesizes the imaging findings of 3 diagnostic imaging modalities for optimal visualization and is the youngest reported case of pigmented villonodular synovitis of the flexor hallucis longus tendon.

Performance of ACR TI-RADS and the Bethesda System in Predicting Risk of Malignancy in Thyroid Nodules at a Large Children's Hospital and a Comprehensive Review of the Pediatric Literature.

While thyroid nodules are less common in children than in adults, they are more frequently malignant. However, pediatric data are scarce regarding the performance characteristics of imaging and cytopathology classification systems validated to predict the risk of malignancy (ROM) in adults and select those patients who require fine-needle aspiration (FNA) and possibly surgical resection. We retrospectively reviewed the electronic medical records of all patients 18 years of age or younger who underwent thyroid FNA at our institution from 1 July 2015 to 31 May 2022. Based on surgical follow-up from 74 of the 208 FNA cases, we determined the ROM for the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) ultrasound risk stratification system and The Bethesda System for Reporting Thyroid Cytopathology and added our results to those of pediatric cohorts from other institutions already published in the literature. We found the following ROMs for 1458 cases using ACR TI-RADS (TR): TR1. Benign: 2.2%, TR2. Not Suspicious: 9.3%, TR3. Mildly Suspicious: 16.6%, TR4. Moderately Suspicious: 27.0%, and TR5. Highly Suspicious 76.5%; and for 5911 cases using the Bethesda system: Bethesda I. Unsatisfactory: 16.8%, Bethesda II. Benign: 7.2%, Bethesda III: Atypia of Undetermined Significance: 29.6%, Bethesda IV. Follicular Neoplasm: 42.3%, Bethesda V. Suspicious for Malignancy: 90.8%, and Bethesda VI. Malignant: 98.8%. We conclude that ACR TI-RADS levels imply higher ROMs for the pediatric population than the corresponding suggested ROMs for adults, and, in order to avoid missing malignancies, we should consider modifying or altogether abandoning size cutoffs for recommending FNA in children and adolescents whose thyroid glands are smaller than those of adults. The Bethesda categories also imply higher ROMs for pediatric patients compared to adults.

Spondyloepiphyseal dysplasia congenita: Use of complementary 3D reconstruction imaging for preoperative planning.

We present a case of spondyloepiphyseal dysplasia congenita (SEDC), a rare autosomal dominant genetic disorder that results in short stature and skeletal anomalies. Children with SEDC have disproportionate short-trunked short stature, platyspondyly, coxa vara, and epiphyseal involvement. Those with coxa vara can develop osteoarthritis of the hip early and a valgus hip osteotomy is recommended to preserve hip function and delay progression to osteoarthritis. Surgery is difficult due to the three-dimensional deformity, unossified femoral head, and small patient size. In this case, a patient-specific surgical plan and implant sizing was developed using a composite 3D reconstruction from computed tomography (CT) and magnetic resonance imaging (MRI). The complementary use of both modalities allowed for a complete visualization of the patient's dysplastic femoral head & neck anatomy.

Congenital venolobar syndrome, pulmonary sequestration, and horseshoe lung in a newborn female.

A 6-day-old female presented to a pediatric cardiologist with tachypnea. A computed tomography angiogram of the chest showed partial anomalous pulmonary venous return, a pulmonary sequestration, and a horseshoe lung. Depicted here are radiographic findings which display this rare combination. This case demonstrates the need for the radiologist to consider additional abnormalities in the setting of anomalous pulmonary venous return.

Opiate leukoencephalopathy in a pediatric patient.

A 17-year-old male presented from an outside facility in acute respiratory failure and profound hypotension. He was found to have classic MRI brain findings of opiate-induced leukoencephalopathy which was corroborated with urine drug screen and history. This entity has been described in the adults but is not as well recognized in the pediatric population. As the opiate epidemic continues to evolve, this case brings heightened awareness of this disorder to pediatric radiologists.

Unique neuroradiological findings in propionic acidemia.

Propionic acidemia is a rare metabolic disorder that affects the catabolism of branched-chain amino acids and oddchain fatty acids. Propionic acidemia is one of the least common organic acidemias. Presented here are manifestations not previously characterized. The first case is an infant with diffuse subcortical diffusion restriction and vermian atrophy. The second case is an adolescent with asymmetric cortical volume loss and contralateral cortical diffusion restriction. These unique brain MRI findings of propionic acidemia may aid the neuroradiologist in guiding genetic testing for occult metabolic disease.