Abstract
Bronchogenic cysts are rare congenital lesions, typically identified in childhood but occasionally found in adults as incidental findings on imaging. In oncology patients, these lesions can present a diagnostic challenge due to their potential to mimic metastatic disease. We report a case of a 78-year-old woman undergoing routine surveillance for Stage II colorectal cancer who was found to have a paratracheal cystic lesion suspicious for malignancy. Ultrasound-guided fine needle aspiration (US-FNA) targeted posterior to the carotid artery and aspirated necrotic material, yielding pathognomonic ciliated epithelium without malignancy. Coupled with absent FDG avidity on PET and negative cultures, cytology confirmed a benign bronchogenic cyst, excluding metastasis and preventing unnecessary treatment. This case underscores that cervical bronchogenic cysts are critical malignancy mimics in oncology patients and demonstrates US-FNA's unique utility in obtaining contamination-free diagnostic samples, overcoming limitations of other approaches, to avert intervention risks during cancer surveillance.