Patterns of Growth of Tumors in Li-Fraumeni Syndrome by Imaging: A Case Series.

Although tumors of Li-Fraumeni syndrome (LFS) have a premalignant or dormant phase that could be exploited by early imaging detection, this has been underevaluated in the literature. We present a case series of patients with LFS followed by imaging over time to highlight patterns of growth of tumors and hotspots of missed tumors in this population. Clinical and imaging features were available for 29 tumors of 24 carriers of a germline TP53 pathogenic variant, developed between 1999 and 2023 were retrospectively reviewed in a single tertiary pediatric center. Imaging characteristics of tumors were evaluated with MRI, CT, and radiographs. Local invasion, time interval for developing primary cancer, and/or recurrent disease and metastasis, and factors that delayed the tumor diagnosis were assessed. In patients with multiple tumors the median time intervals for development of first, second, and third primary cancers were 45.9, 79.8, and 28.1 months, respectively. Hotspots of missed tumors included superficial soft tissues, areas close to bones, on the scalp, in tissues around the adrenal region and in small hypodense lesions on brain CT. In conclusion, the pattern of growth of tumors is variable and erratic in LFS patients with some tumors presenting with a dormant pattern.

Cranial ultrasound performance assessment tool: development and validation.

AIM: A standard assessment tool for direct evaluation of procedural skills to ensure proficiency of trainees is necessary for cranial ultrasound (US) in clinical practice. This study created and validated an assessment tool for cranial US performance by radiologists. MATERIAL AND METHODS: An initial evaluation tool for cranial US using criteria was developed based on existing literature. The assessment form was modified using a three-round Delphi process by an expert panel, conducted between January 2021 and April 2021. Rubric scales for grading were added once consensus regarding generated items was reached. Experts confirmed the final assessment tool using a rubric scale. Two raters evaluated cranial US performance of 27 residents in video clips using the tool. Reliability and percent agreement were assessed. RESULTS: Seventeen pediatric radiologists working in different settings participated in the expert panel. The content validation of the proposed evaluation tool was enabled by expert pediatric radiologists. Following three rounds of the Delphi process, the initial 14-item assessment form became a final 15-item form. A three-part rubric scale was used in the final form (preparation, US machine operation, and cranial US performance). Interrater reliability was evaluated with Cohen's Kappa. The Kappa value and percent interrater agreement for most items was moderate to almost perfect (0.42-0.93 and 77.8-100%, respectively). The Cronbach's alpha values for both raters were 0.856 and 0.891. CONCLUSIONS: This study produced the first validated cranial US assessment tool using a modified Delphi method. The final assessment form is a simple and reliable tool.

Diagnostic accuracy of imaging approaches for early tumor detection in children with Li-Fraumeni syndrome.

BACKGROUND: The Toronto protocol for cancer surveillance in children with Li-Fraumeni syndrome has been adopted worldwide. OBJECTIVE: To assess the diagnostic accuracy of the imaging used in this protocol. MATERIALS AND METHODS: We conducted a blinded retrospective review of imaging modalities in 31 pediatric patients. We compared imaging findings with the reference standards, which consisted of (1) histopathological diagnosis, (2) corresponding dedicated imaging or subsequent surveillance imaging or (3) clinical outcomes. We individually analyzed each modality's diagnostic performance for cancer detection and assessed it on a per-study basis for chest and abdominal regional whole-body MRI (n=115 each), brain MRI (n=101) and abdominal/pelvic US (n=292), and on a per-lesion basis for skeleton/soft tissues on whole-body MRI (n=140). RESULTS: Of 763 studies/lesions, approximately 80% had reference standards that identified 4 (0.7%) true-positive, 523 (85.3%) true-negative, 5 (0.8%) false-positive, 3 (0.5%) false-negative and 78 (12.7%) indeterminate results. There were 3 true-positives on whole-body MRI and 1 true-positive on brain MRI as well as 3 false-negatives on whole-body MRI. Sensitivities and specificities of tumor diagnosis using a worst-case scenario analysis were, respectively, 40.0% (95% confidence interval [CI]: 7.3%, 83.0%) and 38.2% (95% CI: 29.2%, 48.0%) for skeleton/soft tissues on whole-body MRI; sensitivity non-available and 97.8% (95% CI: 91.4%, 99.6%) for chest regional whole-body MRI; 100.0% (95% CI: 5.5%, 100.0%) and 96.8% (95% CI: 90.2%, 99.2%) for abdominal regional whole-body MRI; sensitivity non-available and 98.3% (95% CI: 95.3, 99.4) for abdominal/pelvic US; and 50.0% (95% CI: 2.7%, 97.3%) and 93.8% (95% CI: 85.6%, 97.7%) for brain MRI. CONCLUSION: Considerations for optimizing imaging protocol, defining criteria for abnormalities, developing a structured reporting system, and practicing consensus double-reading may enhance the diagnostic accuracy for tumor surveillance.

Imaging of a glomus tumor of the liver in a child.

Glomus tumors occur preferentially in the subcutaneous tissue of the fingers and toes, but are extremely rare in visceral organs. Although, there have been several reports of glomus tumors in the liver in adult patients, there have yet been no publications reporting glomus tumors of the liver in children. Here, we report a case of an 11-year-old girl who was admitted with a 2-week history of progressive dyspnea on exertion and vomiting. Upon physical examination, she was found to have hypertension and a palpated smooth, firm mass at the epigastrium. Abdominal MRI revealed a well-defined exophytic hypervascular mass with intratumoral hemorrhage at segment 3/4b of the liver. Ultrasound-guided biopsy revealed it to be a glomus tumor. An ultrasound conducted at a 1-month follow-up after preoperative embolization revealed that the mass had decreased in size. A subsequent exploratory laparotomy with left hepatectomy was performed and the histologic results confirmed the diagnosis.