Pediatric Cryptococcosis Presenting as a Mediastinal Mass: A Case Report And Endobronchial Ultrasound-Guided...

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive diagnostic technique. While widely used in adults, its application for diagnosing mediastinal masses in pediatric patients remains underreported. This gap poses challenges when addressing atypical presentations, such as pulmonary cryptococcosis in immunocompetent children, which is frequently misdiagnosed due to nonspecific symptoms. We present the case of a healthy nine-year-old male with an eight-day history of fever and cough. Computed tomography revealed a mediastinal mass in the left hilum and a mass in the left lower lobe. Following unsuccessful empirical antibiotic therapy, further invasive investigation was warranted. This article describes an EBUS-TBNA protocol tailored for pediatric patients. The procedure was performed using total intravenous anesthesia and a laryngeal mask airway. An ultrasound bronchoscope was advanced, and Doppler imaging was used to confirm the target lymph node's relationship with the surrounding vasculature. In this case, a lesion under the second carina was identified. A 22 G aspiration needle was inserted to a depth of 1-2 cm. Maintaining 5-15 mL of negative pressure, 20-30 rapid agitations were performed to obtain samples. The biopsy samples underwent histopathological examination and next-generation sequencing. The tissue demonstrated positive periodic acid-Schiff and Grocott methenamine silver staining, supporting identification of Cryptococcus spp. Following targeted fluconazole therapy, the patient achieved complete clinical and radiographic recovery. This case illustrates the potential usefulness of EBUS-TBNA in a carefully selected pediatric patient when conventional tests fail.