Mediastinal tumors are common neoplasms among the pediatric population. The symptoms may be due to the direct compression effects on the surrounding structures or "B" like symptoms of specific lymphomas or due to paraneoplastic syndrome. The cardiovascular and respiratory consequences of the compression effects along with the unique physiological nature of the pediatric airway place the anesthesiologist in a difficult situation and face a new situation called "can intubate-cannot ventilate." This clinical scenario is not rare, with physicians commonly being confronted with similar situations in patients with severe bronchospasm. This entity has not been incorporated in any of the difficult airway algorithms. But the mediastinal tumors differ from bronchospasm because they cause physical external compression of the airway. This review will bring the readers the common anterior mediastinal tumors in pediatrics, the physiological differences in the pediatric airway in relation to the compression effects of the mediastinal tumors, and the management aspects of the different surgical aspects of the tumor.

Thymus grows after birth, reaches maximal size after the first few years and involutes by puberty. Because of the postnatal developmental and involutional duration, we aimed toinvestigate normal stiffness values of mediastinal thymus by shear wave elastography (SWE) in different age groups of children and discuss imaging findings of thymus.

We prospectively examined 146 children (90 girls, 56 boys) who underwent a thyroid or neck ultrasound examination. All subjects underwent ultrasound and SWE evaluation of mediastinal thymus by parasternal and suprasternal approach. We subdivided the subjects based on the ages as 0 to 2 months (group 1), >2 to 6 months (group 2); >6 months to 2 years (group 3), >2 to 5 years (group 4), >5 to 8 years (group 5), and greater than 8 years old (group 6).We investigated differences of mean shear wave elasticity (kPa) and shear wave velocity (m/sec) values among age groups and the association of SWE values with age, body mass index (BMI), height, and weight of the patients.

Medians and ranges of age, height, weight, and BMI were 24 (2-84) months, 85 (55-120) cm, 12(4.55-22) kg, 15.37 (13.92-17.51) kg/m2, 11 (2.64-23.15) cc, respectively. Mean shear wave elasticity of thymus when all participants were included was 6.76±1.04 kPa. Differences of mean elasticity values among age groups and also gender groups were not statistically significant. There were highly significant negative correlations among age (r:0.3), height (r:0.26), weight (r:0.3) with elasticity and also velocity values (p<0.001). The thymus elasticity is negatively correlated with age.

Quantitative evaluation of the thymus by SWE provides normative stiffness values based on age and gender groups. The thymus elasticity decreases with increased age, height and weight.

Anatomic variants are common incidental findings in pediatric chest imaging and can be mistaken for true underlying pathology, sometimes resulting in unnecessary additional imaging evaluation or invasive procedures. Clear understanding of the imaging characteristics and clinical significance of anatomic thoracic variants is important for accurate diagnosis and avoidance of unnecessary intervention. This article provides an up-to-date review of anatomic variants in the pediatric chest to increase knowledge and aide in timely, correct diagnosis.

The thymus is a lymphatic organ that undergoes dynamic changes with age and disease. It is important to be familiar with these physiological changes in the thymus gland to be able to identify pathology and make an accurate diagnosis. The thymus may be involved in multisystem disorders or show focal isolated lesions. The aim of this article is to review the radiological anatomy of the thymus, normal variants, and pathology including hyperplasia and benign/malignant lesions involving the thymus gland in the pediatric age group. We also propose an algorithmic approach for imaging evaluation of a suspected thymic mass on the basis of morphologic features.