Initial ultrasound evaluation of an anterior mediastinal mass ultimately diagnosed as T-cell acute lymphoblastic leukemia: a report of three cases in children

Abstract

Pediatric T-cell acute lymphoblastic leukemia (T-ALL) in the anterior mediastinum has an acute onset and requires early treatment. The diagnostic strategy for anterior mediastinal masses in pediatric patients usually involves imaging evaluation, surgical biopsy, or resection for diagnosis and treatment. Thereafter, appropriate chemotherapy regimen selection is based on the pathological diagnosis. In some cases, general anesthesia is avoided to prevent complications such as airway compression and circulatory collapse. We present 3 cases with T-ALL where ultrasound was used for the first evaluation of the anterior mediastinal mass. A 5-year-old girl had lymph node swelling at the supraclavicular fossa. Ultrasound examination showed a huge anterior mediastinal mass with an abnormal thymus, surrounding the proximal main trachea in the mediastinum. These sonographic findings indicated a possibility for tracheal compression during general anesthesia. A 12-year-old boy had dyspnea. Ultrasound examination showed a massive pericardial effusion and stenosis of the right pulmonary artery. These sonographic findings indicated a risk of circulation collapse. An 8-year-old boy had cervical swelling and dyspnea. Ultrasound examination showed a huge mass on the anterior mediastinum and a huge thrombus in the left atrium. This sonographic finding indicated a risk of thromboembolism. Ultrasonography is useful in pediatric patients with anterior mediastinal masses due to T-ALL. By focusing on the thymus, a diagnosis of T-ALL might be recommended. To avoid catastrophic circulation collapse, tracheal and vascular compression should be evaluated. Direct invasion may also be detectable.