Successful Diagnosis of a SMARCA4-Deficient Undifferentiated Tumor via Endobronchial Ultrasound-Guided Fine Needle Aspiration and Endobronchial Biopsies

Lung cancer is the third most prevalent cancer, following breast cancer in women and prostate cancer in men. However, it remains the leading cause of cancer-related mortality. As treatment options have advanced, the significance of accurate diagnosis has increased, enabling targeted and more personalized therapeutic treatments. SMARCA4-deficient thoracic tumors are a relatively new classification of mediastinal lung cancers that are known to be difficult to diagnose with conventional endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA). Newer modalities such as endobronchial ultrasound with cryobiopsy have emerged, and studies have indicated that they offer increased diagnostic yield when coupled with conventional EBUS-TBNA. Here, we present a case in which EBUS-TBNA alone produced sufficient tissue volume for immunohistochemistry at NeoGenomics (Fort Myers, FL), leading to a successful diagnosis.