Safe diagnostic management of malignant mediastinal tumors in the presence of respiratory distress: a 10-year experience

BACKGROUND: The fundamental treatment for patients with pediatric malignant mediastinal tumors is chemotherapy. Therefore, accurate diagnosis is essential for selecting the appropriate chemotherapeutic regimen. However, malignant mediastinal tumors occasionally cause respiratory distress, and biopsies under general anesthesia are dangerous for such patients as invasive mechanical ventilation can aggravate airway obstruction caused by mass effect. In this study, we reviewed our 10-year diagnostic experience to evaluate the efficacy of our practices and confirm a safe diagnostic protocol for future patients. METHODS: We retrospectively reviewed medical records of children with malignant mediastinal tumors diagnosed at Nagoya University Hospital from 2007 to 2018 who demonstrated respiratory distress. Respiratory distress included dyspnea, massive pleural effusion, wheezing, and hypoxemia owing to tumors. Data on sex, age at onset, primary symptoms, location of tumor, management strategy (especially the method of diagnosis and definitive diagnosis), clinical course, prognosis during the acute phase (within 3 months from the onset of respiratory symptoms), and long-term outcome were collected. RESULTS: Twelve pediatric patients met the review criteria. There were seven anterior mediastinal tumors and five posterior mediastinal tumors. All anterior mediastinal tumors were diagnosed via bone marrow smear, thoracentesis, or core needle biopsy while maintaining spontaneous breathing. Regarding posterior tumors, two patients were diagnosed via a core needle biopsy and lymph node excisional biopsy under spontaneous breathing. Two cases were initially diagnosed solely using tumor markers. One patient with severe tracheal compression underwent tumor resection with extracorporeal membrane oxygenation stand-by. No patient died of diagnostic procedure-related complications. CONCLUSIONS: In 11 of the 12 cases reviewed, safe and accurate tumor diagnosis was accomplished without general anesthesia. A diagnostic strategy without general anesthesia considering the tumor location proved to be useful.