Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas

Alveolar Soft Part Sarcoma: Imaging Evaluation

This case report concerns a 16-year-old boy who developed pain in his right thigh after a soccer game. Imaging studies revealed a pathologic transtrochanteric fracture of the right femur, accompanied by a large expansive intramuscular lesion centered in the deep planes of the adductor musculature. Main imaging findings included intense enhancement and vascularization of the lesion, along with peripheral and central flow voids, the latter described as characteristic of this subtype of soft tissue sarcoma. Alveolar soft part sarcoma is a rare and distinctive sarcoma with an indolent clinical course that typically occurs in young patients and predominantly affects the deep tissues of the lower limbs. · Soft tissue sarcomas are a rare group of malignancies, often found in the extremities. Suspicious features include larger size, deeper location, heterogeneous enhancement, and progressive growth.. · Alveolar soft part sarcoma (ASPS), a rare subtype primarily seen in children, is characterized by high T1 signal intensity, intense contrast enhancement, and more than five central and peripheral flow voids that are highly indicative of this condition.. · Magnetic resonance imaging (MRI) is the preferred modality for evaluating these lesions. Advanced MRI techniques, such as diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC), enhance diagnostic confidence, particularly in postoperative evaluations..

Ischial Tuberosity Avulsion Fracture Mimicking Calcified Mass on Plain Films: A Case Report

Ischial tuberosity avulsion fractures are overall uncommon but are known injuries in the adolescent population. They are the result of sudden, forceful contraction of the hamstring muscle groups. The characteristic radiographic appearance of an ischial tuberosity avulsion fracture is of an irregular ischial margin and a nearby avulsed bone fragment. Callous formation may ensue and appears as a calcific density in the region of injury. Awareness of the spectrum of radiographic presentations can help ensure correct diagnosis and minimize concern for alternative underlying diagnoses. This case report describes a 14-year-old boy with a chronic ischial tuberosity avulsion fracture which demonstrated an unusual presentation on radiographs and required MRI to confirm the diagnosis and rule out other potentially ominous pathology.

Ultrasound performance in pediatric deep soft-tissue tumor characterization

This study investigated the performance of ultrasonography in diagnosing deep soft-tissue tumors and tumor-like lesions in children with histological results. Demographic information and ultrasound characteristics of benign and malignant masses were statistically analyzed. Three radiologists (Radiologists 1, 2, and 3) independently reviewed the ultrasonography studies while being blinded to the medical history and other imaging findings. The 82 lesions included in the study were histopathologically classified as malignant (n = 25) or benign (n = 57). No statistically significant differences were observed between the benign and malignant subgroups regarding age (p = 0.059), sex (p = 1.0), disease course (p = 0.812), presence or absence of symptoms (p = 0.534), maximum diameter (p = 0.359), margin (p = 1.0), calcification (p = 0.057), or blood Adler type (p = 0.563). However, statistically significant differences were observed between the benign and malignant subgroups in terms of isolated or Multiple occurrences (p < 0.001), history of malignancy (p < 0.001), shape (p < 0.001), and echogenicity (p < 0.001). Parameters such as tumor shape (p = 0.042, OR = 6.222), single or multiple occurrences (p = 0.008, OR = 17.000), and history of malignancy (p = 0.038, OR = 13.962) were identified as independent predictors of benign and malignant tumors. The diagnostic sensitivities evaluated by the three radiologists were 68.0%, 72.0%, 96.0%, respectively, while the specificities were 77.2%, 82.5%, 77.2%, respectively. Ultrasound demonstrates good performance in the diagnosis of benign deep lesions such as hemangiomas/venous malformation and adipocytic tumors. Multiple irregular morphologies and a history of malignancy were identified as independent risk factors for malignant masses. The experience of radiologists in recognizing specific tumors is important. Careful attention should be paid to masses with ambiguous ultrasound features, as well as small lesions.

Imaging palpable tumors in pediatrics: Part 2

Palpable tumors in children are a common reason for consulting a radiologist. The origin of these lesions varies widely, and although they are common, classic radiology books do not cover some of them. This series of two articles aims to review the clinical and radiological characteristics of a selection of palpable tumors in children that radiologists need to be familiar with.