Objective Inferior vena cava (IVC) tumor thrombus in pediatric abdominal malignancies presents substantial surgical challenges. We evaluated operative strategies, outcomes, and the adequacy of current thrombus classification systems in guiding surgical planning. Methods Children undergoing surgery for abdominal solid tumors with IVC thrombus over a 10-year period were retrospectively reviewed. Thrombus extent was assessed radiologically and intraoperatively, and surgical techniques and outcomes were analyzed. Results Eleven patients (median age 85 months) were included: eight with Wilms tumor, two with adrenocortical carcinoma, and one with neuroblastoma. Origin of thrombus was renal vein in 9 and adrenal vein in 2. Caudal propagation to the iliac bifurcation occurred in one patient, and contralateral renal vein involvement in two. Complete tumor and thrombus resection was achieved in all cases. En bloc resection was feasible in eight patients, whereas three required sequential thrombectomy and tumor excision to reduce hemorrhagic risk. Cavotomy with primary repair of IVC was performed in nine patients. One patient required patch repair of IVC. Another patient had segmental cavectomy. Cardiopulmonary bypass was necessary in two patients due to extensive or adherent thrombus. No major intraoperative complications or early mortality occurred. Median hospital stay was seven days, and nine patients remain in complete remission. Conclusion Complete resection of IVC tumor thrombus in children is feasible with favorable outcomes. Current staging systems have limitations in reflecting surgical complexity. Other parameters like caudal extension, venous wall invasion, and degree of luminal involvement should be incorporated to better guide operative planning

Thoracic neuroblastic tumors pose surgical challenges due to proximity to vital structures. Image-defined risk factors (IDRFs) aid in assessing surgical risks. This study evaluates their impact on surgical decisions, resection extent, and complications. Forty-one children undergoing surgery for thoracic neuroblastic tumors (2007–2020) were analyzed. Group A (n = 22) underwent neoadjuvant chemotherapy followed by surgery; Group B (n = 19) underwent upfront surgery. IDRFs (infiltrative, vascular, neurological, or extensive) were identified via imaging. Tumor volumes were calculated using ellipsoid approximation. Resections were classified as complete or incomplete, and complications graded by the Clavien-Dindo system and Comprehensive Complication Index. At diagnosis, 70

Chronic mucocutaneous candidiasis (CMC) is a condition characterized by persistent or recurrent infections caused by candida species. Gain-of-function (GOF) mutations in signal transducer and activator of transcription-1 (STAT1) have been identified as a major cause of CMC and are linked to a broad clinical spectrum, including increased susceptibility to infections and vascular abnormalities. We present the case of aortic calcification in a patient with a STAT1 GOF mutation. The 8-year-old male patient had recurrent oral ulcers, upper respiratory tract infections, and pneumonia, and was found to have calcifications in the aortic arch and branches. Treatment with ruxolitinib led to significant clinical improvement, although no regression in aortic calcification was observed. STAT1 GOF mutations may enhance a pro-osteogenic environment through sustained activation of the Janus Kinase (JAK)-STAT pathway. This case highlights the potential link between STAT1 GOF mutations and vascular calcification and underscores the need for further investigation into the long-term vascular impact of JAK inhibition.

Fat-containing liver lesions have been widely discussed in the radiology literature and include various benign and malignant lesions. However, data on the presence and imaging characteristics of intralesional fat in hepatoblastoma remain limited. To investigate the presence of intralesional fat in hepatoblastoma using dual-echo magnetic resonance imaging (MRI) and to correlate imaging findings with histopathology. This retrospective study included 22 pediatric patients with hepatoblastoma who underwent pretreatment MRI with a dual-echo gradient-recalled echo sequence. Qualitative visual assessment and semiquantitative analysis using region-of-interest (ROI) measurement were performed to evaluate intralesional fat. Histopathology was accepted as the reference standard for fat detection. Twenty-two patients (8 girls, 14 boys; median age, 11.5 months; range, 3-192 months) with pretreatment dual-echo MRI were included. Histopathologic evaluation demonstrated intratumoral fat in 10 of 22 tumors (45

Certain renal developmental anomalies and non-tumorous lesions in children may mimic malignant tumors, leading to diagnostic challenges. These lesions, known as pseudotumors, require careful differentiation to avoid unnecessary invasive procedures. In this context, imaging techniques play a critical role in differentiating pseudotumors from malignant neoplasms. Ultrasound (US) is the preferred initial imaging modality in pediatric patients. When US findings are inconclusive, magnetic resonance imaging is commonly used as the next step. Computed tomography is less commonly preferred due to ionizing radiation. It is useful to evaluate the lesion along with the clinical and laboratory findings, and the follow-up imaging may be necessary in some cases. This review presents common and uncommon developmental, infectious, granulomatous, vascular, and miscellaneous renal pseudotumors in the pediatric population.

BACKGROUND:The management of rare tumors at reference centers with specialized multidisciplinary tumor boards (MTBs) improves patient survival. No international standardized diagnostic and treatment recommendations for pediatric patients with adrenocortical carcinoma (ACC) exist so far. The aim of this case-based study is to determine how congruent treatment recommendations are in different specialized institutions in different countries. METHODS:In this cross-sectional, case-based survey study, five anonymized patient cases, including imaging data of pediatric adrenocortical carcinomas (pACCs), were distributed to seven international specialized centers located in Brazil, Germany, India, Italy, Poland, Turkey, and the USA. The centers were tasked with providing recommendations regarding the treatment sequence and modalities, as well as indicating the level of consensus on these decisions within their MTBs. For each case, the treatment approach recommended by the highest number of centers was recorded to calculate an agreement percentage relative to all treatment recommendations made. The consensus level for each case was determined on a scale of 1 to 10, with higher scores indicating greater agreement among MTB members. RESULTS:A total of five patient cases were discussed across seven MTBs, yielding a total of 34 treatment recommendations. The agreement percentages for the primary therapeutic approach for each case were as follows: primary therapeutic approach: 88.6%; surgical approaches: 51.8%; and systemic chemotherapy recommendations: 53%. CONCLUSIONS:This study represents the first case-based analysis of international inter-center agreement on pediatric ACC management. Inter-center agreement regarding treatment allocation and sequencing was low, while the level of consensus within each MTB was high. These findings point to potentially significant and clinically relevant differences in treatment standards across centers, highlighting the need for international collaboration and standardized diagnostic and therapeutic recommendations, especially for rare tumors. Increased case-based exchanges between centers are essential to reduce the substantial discrepancies observed here and to further standardize the management of pediatric patients with ACC.

BackgroundHepatoblastoma and hepatocellular carcinoma (HCC) are the most common primary malignant liver tumors in children. Although some characteristic imaging findings have been described in both hepatoblastoma and HCC, it is difficult to distinguish between these two tumors over the 5 years of age.ObjectiveTo investigate clinical and radiological findings that may help differentiate hepatoblastoma and HCC over 5 years of age.Materials and methodsFrom 2007 to 2022, 19 consecutive patients older than 5 years old diagnosed with primary liver malignancy were yielded from our radiology archive retrospectively. Imaging features, age, sex, treatment, and follow-up data were recorded.ResultsA total of 19 patients (16 boys; median age 7.5, min-max 5-17), ten HCCs and nine hepatoblastomas, were included. Serum alpha-fetoprotein (sAFP) values were significantly higher in hepatoblastoma patients (n=9), compared to the HCC (n=10) (P=0.002). Tumor size and PRETEXT stages were higher in hepatoblastoma patients; however, there was no statistical difference (P=0.06). Initial MRI was available for six patients with hepatoblastoma and seven patients with HCC, and there was no difference regarding ADCmin values.ConclusionIn the differential diagnosis of primary malignant liver tumor in a child older than 5 years of age, higher sAFP level may support the diagnosis of hepatoblastoma rather than HCC.

To evaluate the potential of zero-echo time-magnetic resonance imaging (ZTE-MRI) in the assessment of urolithiasis and compare ZTE-MRI with computed tomography (CT) in pediatric patients. This was a single-center, prospective cross-sectional study conducted between April 2023 and December 2023. 23 patients (12 girls, 11 boys; mean age: 12.3, range 1–18) with urinary tract stones detected on non-enhanced abdominal CT were enrolled. The images were evaluated independently by two radiologists for the presence, and number of stones in the kidneys, ureters, and bladder. In the second session, two radiologists evaluated whether urinary tract stones could be detected by MRI compared to CT, and the maximum diameter of the stones was measured. The CT and MRI results were compared with the Wilcoxon test. The agreement between the results of the observers was examined using Spearman’s rho correlation coefficient and the intraclass correlation coefficient. A total of 58 urinary tract stones were detected by CT and 39 of these were detected by MRI. Most of the stones that MRI could not detect were < 5 mm and the detection sensitivity of MRI increased in correlation with stone size (p < 0.001). There was poor intermodality agreement for stones < 5 mm, substantial agreement for stones 5–10 mm, and almost perfect agreement for stones > 10 mm. Interobserver agreement for stone detection on MRI was almost perfect for stones > 10 mm and 5–10 mm and was substantial for stones < 5 mm. ZTE-MRI is a promising modality for detecting urinary stones without radiation exposure in children. Zero-echo time-magnetic resonance imaging is a potential method for identifying urinary stones in children and other populations who are particularly sensitive to radiation.

BACKGROUND:Pulmonary Langerhans cell histiocytosis (pLCH) is a rare disease, mostly a component of multisystemic LCH. We aimed to investigate the clinical features and treatment results in children with pLCH. METHODS:We retrospectively reviewed the clinical, radiological, and treatment data of 37 patients with pLCH, diagnosed from 1974 to 2022. RESULTS:10% (n=37) of 367 patients with LCH had lung involvement. The median age was 1.8 years (range: 0.4 & 17.7) with a male-to-female ratio of 2.3. At admission 29.7% (n=11) presented with respiratory symptoms. Imaging showed a spectrum from nodular opacities to multiple cysts. All but one patient had multisystem disease. Twenty-nine received vinblastine-containing therapy. Ten-year event-free (EFS) and overall survival (OS) rates were 47.8% and 63.3%, respectively. In children younger and older than two years of age, the 10-year EFS was 53.3% vs. 40.2% and the 10-year OS was 58.7% vs. 68.8%, respectively. In children with and without risk organ involvement, 10-year EFS was 51.9% vs. 46.3% and 10-year OS was 51.9% vs. 73.7%. CONCLUSIONS:Lung and multisystem involvement are significant concerns in LCH, highlighting the need for careful management to reduce morbidity and mortality.

Machine learning methods can be applied successfully to various medical imaging tasks. Our aim with this study was to build a robust classifier using radiomics and clinical data for preoperative diagnosis of Wilms tumor (WT) or neuroblastoma (NB) in pediatric abdominal CT. This is a single-center retrospective study approved by the Institutional Ethical Board. CT scans of consecutive patients diagnosed with WT or NB admitted to our hospital from January 2005 to December 2021 were evaluated. Three distinct datasets based on clinical centers and CT machines were curated. Robust, non-redundant, high variance, and relevant radiomics features were selected using data science methods. Clinically relevant variables were integrated into the final model. Dice score for similarity of tumor ROI, Cohen’s kappa for interobserver agreement among observers, and AUC for model selection were used. A total of 147 patients, including 90 WT (mean age 34.78 SD: 22.06 months; 43 male) and 57 NB (mean age 23.77 SD:22.56 months; 31 male), were analyzed. After binarization at 24 months cut-off, there was no statistically significant difference between the two groups for age (p = .07) and gender (p = .54). CT clinic radiomics combined model achieved an F1 score of 0.94, 0.93 accuracy, and an AUC 0.96. In conclusion, the CT-based clinic-radiologic-radiomics combined model could noninvasively predict WT or NB preoperatively. Notably, that model correctly predicted two patients, which none of the radiologists could correctly predict. This model may serve as a noninvasive preoperative predictor of NB/WT differentiation in CT, which should be further validated in large prospective models. CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively. • CT radiomics features can predict Wilms tumor or neuroblastoma from abdominal CT preoperatively. • Integrating clinic variables may further improve the performance of the model. • The performance of the combined model is equal to or greater than human readers, depending on the lesion size.

The authors declare no conflict of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.

Spontaneous pneumothorax is a common clinical condition due to several etiologies. Appropriate radiologic assessment helps avoid re-imaging and guide individualized management. To describe the etiologic factors of spontaneous pneumothorax in children from a radiological perspective. Thirty-nine children with spontaneous pneumothorax were evaluated according to their demographic characteristics, the presence of underlying lung diseases, and imaging findings. Twenty-one patients without underlying lung disease were assessed as primary spontaneous pneumothorax; eight of these 21 patients (38.9

Aim: Malignant chest wall tumors are rare in children.We aimed to study the management of the Ewing family of tumors (EFT) in the chest walls of children. Materials and Methods:The files of patients diagnosed with primitive neuro-ectodermal tumor and Ewing sarcoma of the chest wall in the prior 2 decades were retrospectively reviewed.Results: A total of 15 children with a median age of 10 (8-14) years were included.Their symptoms were palpable mass (n=6), chest pain (n=4), B symptoms (n=2), cough (n=2) and abdominal pain.Their history revealed delayed diagnoses in 1/3 of the patients due to a misinterpretation of the symptoms.All children except for one had tru-cut biopsy and upfront chemotherapy.The median greatest diameter of mass at diagnosis was 100 (67-148) mm and 51 (39-100) mm at preoperative imaging after chemotherapy.Pleural effusion (n=8), costal destruction (n=9), extension to neural foramina (n=3), pulmonary or diaphragmatic nodule (n=5) and distant bone metastasis (n=4) were present at diagnosis in some cases.More than one surgery was performed in 9 (60%) of the children in order to remove the primary tumor and metastases.Costal excision (n=11), diaphragmatic resection (n=6) and chest wall reconstruction with graft material were performed on 8 patients.All cases had radiotherapy postoperatively.Mortality occurred in 9 (60%) patients due to local recurrences or metastases.Only 3 children reached 5-year survival and were considered to be cured.The remaining 3 patients completed their first line oncologic treatments and were under surveillance without treatment. Conclusion:The EFT in the chest wall are aggressive tumors with poor prognosis despite multimodality treatment.Surgeons dealing with these patients should be familiar with complex chest wall reconstruction techniques.

PURPOSE:Pediatric lung tumors are primarily discussed in the surgical literature. However, limited research has been reported on their imaging findings, and only a few tumor types have been documented. Therefore, the aim of this article is to describe the imaging features of primary lung tumors in children. METHODS:The archives of the pediatric radiology unit were reviewed for primary lung tumors documented between 2007 and 2023. In total, 24 patients (9 girls and 15 boys; aged 5 months to 16 years) were included in the study. Their demographic characteristics, clinical presentation, and histopathologic results were obtained. All imaging studies were reviewed by two radiologists for various findings (e.g., lymphadenopathy, atelectasis, pleural effusion, calcification, multiplicity, pneumothorax, axial and lobar location, laterality, tumor margin, mediastinal shift, contrast enhancement pattern, signal intensity on T1- and T2-weighted images, and diffusion pattern), and a final decision was made by consensus. The mean tumor size was compared between the benign and malignant groups using a t-test. RESULTS:There were 15 (62.5%) benign tumors, as follows: inflammatory myofibroblastic tumor (IMT; n = 10, 41%), hemangioma (n = 2, 8%), pneumocytoma (n = 2, 8%), and mature cystic teratoma (n = 1, 4%). Moreover, there were 9 (37.5%) malignant tumors, as follows: pleuropulmonary blastoma (PPB; n = 6, 25%), adenocarcinoma (n = 2, 8%), and lymphoepithelioma-like carcinoma (LELC) (n = 1, 4%). The most frequently reported symptoms were cough, fever, dyspnea, chest pain, and recurrent infection; six patients reported no clinical symptoms. Fifteen tumors (62%) were located in the right lung. The mean tumor diameter at the time of diagnosis was 6.4 ± 3 cm (benign group: 6.7 ± 3.4 cm; malignant group: 6 ± 2.3 cm, P > 0.050). Calcification was present in 80% of the patients with IMT. At the time of diagnosis, two (8.3%) patients were found to have metastasis: one was diagnosed with adenocarcinoma and the other with LELC. Tumors were located peripherally in 18 (75%) patients. CONCLUSION:The symptoms associated with lung masses are non-specific. There is no correlation between tumor size and malignancy. The most common tumors observed in this study were IMT and PPB, respectively. IMT is highly associated with calcification. CLINICAL SIGNIFICANCE:Primary lung tumors are rarely seen in children, and they have different histopathological types. Calcification might be an important radiological clue for the diagnosis of IMT, which is the most common lung tumor in children.

Sarcoidosis is a granulomatous inflammatory disease of uncertain cause. It occurs most commonly in young and middle-aged adults and less frequently in children; therefore, few data on pediatric sarcoidosis exist in the literature. The diagnosis and management of sarcoidosis remain challenging because of diverse and often nonspecific clinical and imaging findings. In addition, the clinical picture varies widely by age. Prepubertal and adolescent patients often present with adult-like pulmonary disease; however, early-onset sarcoidosis is typically characterized by the triad of arthritis, uveitis, and skin rash. Sarcoidosis is mostly a diagnosis of exclusion made by demonstrating noncaseating granulomas at histopathologic examination in patients with compatible clinical and radiologic findings. Although sarcoidosis often affects the lungs and thoracic lymph nodes, it can involve almost any organ in the body. The most common radiologic manifestation is pulmonary involvement, characterized by mediastinal and bilateral symmetric hilar lymphadenopathies with perilymphatic micronodules. Abdominal involvement is also common in children and often manifests as hepatomegaly, splenomegaly, and abdominal lymph node enlargement. Although neurosarcoidosis and cardiac sarcoidosis are rare, imaging is essential to the diagnosis of central nervous system and cardiac involvement because of the risky biopsy procedure and its low diagnostic yield due to focal involvement. Being familiar with the spectrum of imaging findings of sarcoidosis may aid in appropriate diagnosis and management. (C) RSNA, 2023

PURPOSE:Focal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI). Distinguishing these pseudolesions from liver lesions may make diagnosis challenging. The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium.METHODS:A total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study. The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations.RESULTS:The liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated. Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified. The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively. All fat spared areas were hyperintense in the hepatobiliary phase images. The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6) and 1.11 (range, 0.45-1.9), respectively.CONCLUSION:Focal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.