Radiomics in differential diagnosis of Wilms tumor and neuroblastoma with adrenal location in children.

OBJECTIVES: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. CLINICAL RELEVANCE STATEMENT: CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively. KEY POINTS: • 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.

Imaging Features of Pediatric Sarcoidosis.

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. ©RSNA, 2023 Test Your Knowledge questions are available in the supplemental material.

Liver magnetic resonance elastography and fat fraction in pediatric patients with cystic fibrosis versus healthy children.

BACKGROUND: Liver involvement is an important cause of morbidity and mortality in patients with cystic fibrosis (CF). While liver biopsy is the gold standard for demonstrating involvement, its invasiveness prompts a search for noninvasive alternatives. OBJECTIVE: To evaluate liver involvement in pediatric patients with CF (versus healthy controls) using magnetic resonance (MR) elastography/spectroscopy and to correlate the imaging findings with clinical/laboratory characteristics. MATERIALS AND METHODS: This was a single-center, prospective cross-sectional study conducted between April 2020 and March 2022 in patients with CF versus healthy controls. Patients with CF were divided into two subgroups: those with CF-related liver disease and those without. MR images were acquired on a 1.5-tesla machine. Kilopascal (kPa) values were derived from processing MR elastography images. MR spectroscopy was used to measure liver fat fraction, as an indication of hepatosteatosis. Groups were compared using either the Student's t test or the Mann‒Whitney U test. The chi-square test or Fisher's exact test were used to compare qualitative variables. RESULTS: Fifty-one patients with CF (12 ± 3.3 years, 32 boys) and 24 healthy volunteers (11.1 ± 2.4 years, 15 boys) were included in the study. Median liver stiffness (P=0.003) and fat fraction (P=0.03) were higher in the CF patients than in the controls. Median liver stiffness values were higher in CF patients with CF-related liver disease than in those without CF-related liver disease (P=0.002). Liver stiffness values of CF patients with high alanine aminotransferase (ALT), high gamma-glutamyl transferase, and thrombocytopenia were found to be higher than those without (P=0.004, P<0.001, P<0.001, respectively). Only the high ALT group showed a high fat fraction (P=0.002). CONCLUSIONS: Patients with CF had higher liver stiffness than the control group, and patients with CF-related liver disease had higher liver stiffness than both the CF patients without CF-related liver disease and the control group. Patients with CF had a higher fat fraction than the control group. Noninvasive assessment of liver involvement using MR elastography/spectroscopy can support the diagnosis of CF-related liver disease and the follow-up of patients with CF.

Beyond Wilms tumor: imaging findings and outcomes of rare renal tumors in children.

BACKGROUND: Compared to Wilms, non-Wilms renal tumors in children are less well understood due to their rare occurrence which limits precise definition of the typical imaging patterns. OBJECTIVE: This study aims to identify distinctive imaging findings, demographic characteristics and prognosis of pediatric non-Wilms renal tumors. MATERIALS AND METHODS: From January 2007 to December 2018, 207 patients with a diagnosis of primary kidney neoplasia were yielded from our radiology archive, 171 of whom were diagnosed with Wilms tumor, 4 with angiomyolipoma and one with nephrogenic rest. The remaining 31 patients with a diagnosis of primary kidney neoplasia were enrolled in this retrospective study. Imaging data, age, gender, prognosis and findings regarding follow-up were noted. RESULTS: Eight patients had renal cell carcinoma, seven had clear cell sarcoma, six had mesoblastic nephroma, four had rhabdoid tumor, three had desmoplastic small round cell tumor, two had cystic nephroma and one had metanephric stromal tumor. The age of diagnosis was > 8 years for renal cell carcinoma and desmoplastic small round cell tumor, < 5 years for rhabdoid tumor and < 7 months for mesoblastic nephroma. There was no gender preference for any tumor type. The prognosis for rhabdoid tumor was extremely poor in that all the patients followed up in our institute were deceased, whereas no recurrence was found in other tumors. Translocation type renal cell carcinoma had lower T2-weighted signal intensity, mesoblastic nephroma was a predominantly cystic mass, clear cell sarcoma was generally larger at presentation and extensive amorphous calcifications were seen in desmoplastic small round cell tumor. CONCLUSION: For the differential diagnosis of pediatric non-Wilms renal tumors, age is the most important factor, followed by propensity to metastasize/aggressive behavior of the mass. Knowledge of specific imaging findings of these tumors may help to narrow the differential diagnosis.

Radiation dose levels of thoracic-lumbar spine CT in pediatric trauma patients and assessment of scan parameters for dose optimization.

BACKGROUND: CT is frequently used for assessing spinal trauma in children. OBJECTIVE: To establish the local diagnostic reference levels of spine CT examinations in pediatric spinal trauma patients and analyze scan parameters to enable dose optimization. MATERIALS AND METHODS: In this retrospective study, we included 192 pediatric spinal trauma patients who underwent spine CT. Children were divided into two age groups: 0-10 years (group 1) and 11-17 years (group 2). Each group was subdivided into thoracic, thoracolumbar and lumbar CT groups. CT acquisition parameters (tube potential, in kilovoltage [kV]; mean tube current-time product, in milliamperes [mAs]; reference mAs; collimated slice width; tube rotation time; pitch; scan length) and radiation dose descriptors (volume CT dose index [CTDIvol] and dose-length product [DLP]) were recorded. The CTDIvol and DLP values of spine CTs obtained with different tube potential and collimated slice width values were compared for each group. RESULTS: CTDIvol and DLP values of thoracolumbar spine CTs in group 1 and lumbar spine CTs in group 2 were significantly lower in CTs acquired with low tube potential levels (P<0.05). CTDIvol and DLP values of thoracolumbar spine CTs in both groups and lumbar spine CTs in group 2 acquired with high collimated slice width values were significantly lower than in corresponding CTs acquired with low collimated slice width values (P<0.05). CONCLUSION: Pediatric spine CT radiation doses can be notably reduced from the manufacturers' default protocols while preserving image quality.

Early postoperative complications in pediatric abdominal solid tumor surgery according to Clavian-Dindo classification.

PURPOSE: Postoperative period after abdominal solid tumor surgery is critical regarding complications. This study aimed to detect incidence and treatment of complications. METHODS: Single center retrospective study including years 2010-2019 for early postoperative complications were documented and graded according to Clavian-Dindo classification. RESULTS: The overall complication rate was 10% and they were chylous leak (n = 8, 2%), collection in surgical field (n = 8, 2%), acute renal failure (n = 7, 1.7%), hemorrhage (n = 5, 1.3%), intestinal obstruction (n = 4, 1%), surgical site infection (n = 3, 0.7%), thromboembolism (n = 3, 0.7%) and peripheric neuronal event (n = 2, 0.5%). Distribution of complications according to Clavian-Dindo classification was as follows: 2 grade I, 23 grade II, 9 grade IIIb, 5 grade IVa and 1 grade V. While age and percentage of benign or malignant disease were not different in groups with or without complications (p = 0.11, p = 0.24), males had more complications than female patients (p = 0.008). Having more than one surgery aiming tumor resection was associated with increased postoperative complications (p = 0.002). Incidence of complications were highest after extragonadal germ cell tumor (35%) and hepatic tumors (29%). CONCLUSIONS: Postoperative complications of abdominal tumor surgery are diverse in children. They are related with prolonged hospital stay and need for medical or surgical interventions. Number of surgeries, organ of origin and tumor type have an influence on risk of complications.

Further defining the clinical and molecular spectrum of acromesomelic dysplasia type maroteaux: a Turkish tertiary center experience.

Acromesomelic dysplasia type Maroteaux (AMDM, OMIM #602875) is an autosomal recessive disorder characterized by severe short stature, shortened middle and distal segments of the limbs, redundant skin of fingers, radial head subluxation or dislocation, large great toes and cranium, and normal intelligence. Only the skeletal system appears to be consistently affected. AMDM is caused by biallelic loss-of-function variants in the natriuretic peptide receptor B (NPRB or NPR2, OMIM #108961) which is involved in endochondral ossification and longitudinal growth of limbs and vertebrae. In this study, we investigated 26 AMDM patients from 22 unrelated families and revealed their genetic etiology in 20 families, via Sanger sequencing or exome sequencing. A total of 22 distinct variants in NPR2 (14 missense, 5 nonsense, 2 intronic, and 1 one-amino acid deletion) were detected, among which 15 were novel. They were in homozygous states in 19 patients and in compound heterozygous states in four patients. Parents with heterozygous NPR2 variants were significantly shorter than the control. Extra-skeletal abnormalities, including global developmental delay/intellectual disability, nephrolithiasis, renal cyst, and oligodontia were noted in the patient cohort. The high parental consanguinity rate might have contributed to these findings, probably associated with other gene variants. This study represents the largest cohort of AMDM from Turkey and regional countries and further expands the molecular and clinical spectrum of AMDM.

Wilms Tumor Extension Into Duplex Ureter in a 10-Year-Old Girl.

Ureteral extension of Wilms tumor (WT) is a rare occasion. The association of duplex collecting system and WT is extremely rare. Ureteral extension of WT in a duplex collecting system is an unreported entity to date. A 10-year-old girl presenting with WT extending into upper pole ureter of duplex system is reported to emphasize the importance of preoperative diagnosis to plan step by step surgery in this rare coincidental situation.

Magnetic resonance imaging of pulmonary infection in immunocompromised children: comparison with multidetector computed tomography.

BACKGROUND: Computed tomography (CT) is commonly used to detect pulmonary infection in immunocompromised children. OBJECTIVE: To compare MRI and multidetector CT findings of pulmonary abnormalities in immunocompromised children. MATERIALS AND METHODS: Seventeen neutropaenic children (6 girls; ages 2-18 years) were included. Non-contrast-enhanced CT was performed with a 64-detector CT scanner. Axial and coronal non-enhanced thoracic MRI was performed using a 1.5-T scanner within 24 h of the CT examination (true fast imaging with steady-state free precession, fat-saturated T2-weighted turbo spin echo with motion correction, T2-weighted half-Fourier single-shot turbo spin echo [HASTE], fat-saturated T1-weighted spoiled gradient echo). Pulmonary abnormalities (nodules, consolidations, ground glass opacities, atelectasis, pleural effusion and lymph nodes) were evaluated and compared among MRI sequences and between MRI and CT. The relationship between MRI sequences and nodule sizes was examined by chi- square test. RESULTS: Of 256 CT lesions, 207 (81%, 95% confidence interval [CI] 76-85%) were detected at MRI. Of 202 CT-detected nodules, 157 (78%, 95% CI 71-83%) were seen at motion-corrected MRI. Of the 1-5-mm nodules, 69% were detected by motion-corrected T2-weighted MRI and 38% by HASTE MRI. CONCLUSION: Sensitivity of MRI (both axial fat-saturated T2-weighted turbo spin echo with variable phase encoding directions (BLADE) images and HASTE sequences) to detect pulmonary abnormalities is promising.

Lipoblastoma in children: Review of 12 cases.

BACKGROUND: Lipoblastoma is a rare benign mesenchymal tumor of infancy and early childhood. Symptoms vary depending on localization, and signs of compression of adjacent organs may be seen. METHODS: A total of 12 children with pathologically proven lipoblastoma from 2000 to 2014 were reviewed retrospectively for their clinical features, treatment and follow up. RESULTS: There were seven boys and five girls between 7.5 months and 7.5 years of age. The most common symptom was painless rapid-growing mass. The tumors were located in the neck, the abdomen, the groin, pelvis, axilla, glutea, labium majus, thigh and trunk. The largest tumor was in a retroperitoneal location and was 13 × 10 cm in size. Complete resection was performed in 10 patients. All of these patients were followed without any evidence of recurrence. Subtotal excision was performed in two patients. At a median follow up of 38 months (range, 1.8 months-10 years), all patients were disease free. CONCLUSIONS: Lipoblastoma should be considered in the differential diagnosis of rapidly growing mass in patients <3 years of age. Total excision is the treatment of choice with preservation of vital organs. The prognosis is excellent despite large tumor size and local invasion. Recurrence rate is high in incompletely resected tumors. Regular follow up is important for early detection of recurrence.

Chronic necrotizing pulmonary aspergillosis in an immunocompetent patient after the surgery of hydatid cyst.

Chronic necrotizing pulmonary aspergillosis (CNPA) is a condition caused by the ubiquitous fungus Aspergillus fumigatus in non-immunocompromised individuals. Numerous underlying conditions have been associated with CNPA. Tuberculosis, non-tuberculous mycobacterial infection and allergic bronchopulmonary aspergillosis (ABPA) remain the predominant risk factors for development of CNPA. Development of CNPA in echinococcal cyst cavities is very rare and the optimal therapeutic regimen and treatment duration have not been established. Here, we present a case of CNPA developed six years after the cystectomy operation of hydatid cyst and treated with voriconazole successfully.

Diagnosis and treatment of pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is a rare genetic disease caused by mutations in sodium-phosphate co-transporter (SLC34A2), which encodes a type 2b sodium phosphate co-transporter. Disease is characterized by intra-alveolar microlith formation of phosphate. Turkey has a high prevalence of PAM. Herein, we report the clinical and radiological findings of three patients diagnosed with PAM and treated with disodium etidronate.

Traumatic Rupture of Choledochal Cyst in Children: Use of Computed Tomography in the Emergency Department.

The case of an 11-year-old girl who developed acute abdomen after an accidental fall over an iron bar is reported to discuss the diagnostic features and treatment options for traumatic rupture of a choledochal cyst (CC) in children. The patient was admitted to the emergency department with complaints of vomiting and abdominal pain. Physical examination revealed tenderness at the right upper quadrant of the abdomen. Computed tomography findings revealed a rupture of a type IV CC and laceration of the liver. Cholecystectomy, total excision of the cyst, and hepaticojejunostomy were performed. Traumatic rupture of a CC is extremely rare in children, and only 2 cases have been reported. Because patients can be misdiagnosed as experiencing liver hematoma, computed tomography should be performed for all patients with free fluid in the abdomen and cystic mass on the initial evaluation.

Imaging Findings of Fetal-Neonatal Ovarian Cysts Complicated With Ovarian Torsion and Autoamputation.

OBJECTIVE: Large nonresolving neonatal ovarian cysts may be a risk factor for complications such as torsion, mass effect, rupture, intracystic hemorrhage, and autoamputation. Torsed cysts and autoamputated cysts can cause a diagnostic dilemma. The objective of our study was to correlate the imaging findings of intrauterine ovarian torsion and autoamputated ovaries with their pathologic findings. MATERIALS AND METHODS: We retrospectively analyzed the pre- and postnatal medical records, sonographic findings, operation notes, and pathologic reports of 15 patients with ovarian torsion. All patients had complex cysts noted on postnatal sonographic examination. A complex heterogeneous ovarian cyst was defined by the presence of a fluid-debris level indicating hemorrhage within the cyst, a retracting clot, septations with or without internal echoes, calcification, and a solid component. RESULTS: On ultrasound examination, four cysts had solid components, and 11 were heterogeneous and had a fluid-debris level. Calcifications were seen in two patients. The mean patient age at the time of surgery was 3.9 months. Exploratory laparotomy was performed on all patients. Torsed ovaries were identified in five patients. Ten patients had ovaries that were floating free in the peritoneal cavity at the time of surgery. Histopathologic evaluation revealed that 11 of the cysts consisted of extensive hemorrhagic, necrotic autolytic tissue with dystrophic calcification. None of the cysts contained any ovarian tissue. CONCLUSION: A complex heterogeneous ovarian cyst with a fluid-debris level indicating hemorrhage is a significant sonographic hallmark for the diagnosis of ovarian torsion. A calcified abdominal mass, with or without wandering, can be an autoamputated ovary.

Imaging findings of pediatric rheumatologic emergencies.

OBJECTIVE. Pediatric rheumatologic diseases can present with a wide spectrum of clinical features, affecting any organ in the body and causing significant morbidity and mortality. The aim of this review is to emphasize the diagnostic imaging findings of pediatric rheumatologic emergencies and to discuss their pertinent complications. CONCLUSION. Because of their multiorgan and multisystem involvement, pediatric rheumatologic diseases comprise a wide spectrum of differential diagnosis. Although the diagnosis may generally not be time critical, for a few conditions, prompt recognition is crucial to preserving organ function or the patient's life [ 1 ].

Imaging of childhood inflammatory myofibroblastic tumor.

BACKGROUND: Inflammatory myofibroblastic tumor is a rare benign neoplasm and most commonly involves the lung but occurs in extrapulmonary locations. OBJECTIVE: To present imaging findings in inflammatory myofibroblastic tumors in children based on a single-centre experience. MATERIALS AND METHODS: We retrospectively reviewed CT and MRI findings of children diagnosed with inflammatory myofibroblastic tumor in a single institution. RESULTS: We identified 15 children (range: 1-17 years) with inflammatory myofibroblastic tumor. The tumor was localized to the lung (n = 5), mediastinum (n = 3), trachea (n = 1), bronchus (n = 1), abdomen (n = 2) and orbit (n = 3). All the extraorbital tumors were solid masses with homogeneous or heterogeneous enhancement. Four lung tumors and one posterior mediastinal tumor contained calcification. Local recurrence following surgical removal occurred in two children with invasion of the esophagus and of the left atrium in one. Localized masses were seen in all children with orbital tumour. Two of these had episcleritis and perineuritis; one had episcleritis, tendonitis, perineuritis, myositis and dacryoadenitis. CONCLUSION: The locations and imaging features of inflammatory myofibroblastic tumors are variable.

Imaging features of primary malignant pancreatic tumors in children.

OBJECTIVE: The purpose of this article is to describe the sonographic, CT, and MRI features of primary malignant pancreatic tumors of childhood. CONCLUSION: Most children with a pancreatic tumor present with a solid pseudopapillary tumor that is usually well marginated and has solid and cystic areas surrounded by a fibrous capsule. Pancreatoblastoma is more aggressive than solid pseudopapillary tumor. The imaging features are those of a large heterogeneous tumor. Ductal adenocarcinoma is rare in children and has a poor prognosis.

Pure endobronchial inflammatory myofibroblastic tumor in children.

Isolated endobronchial inflammatory myofibroblastic tumor is an unusual diagnosis among endobronchial masses in childhood. The presenting signs and symptoms may mimic asthma. Rigid bronchoscopy is effective for the diagnosis and treatment. Follow-up is mandatory to check for recurrent disease. Here in, the authors report on a 9-year-old girl with endobronchial inflammatory myofibroblastic tumor to emphasize the possibility of endobronchial lesion in children with longstanding obstructive symptoms.

Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images.

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.

Imaging findings of primary lung tumors in children.

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.