C78-36 Delayed Tracheoseophageal Fistula in Untreated Lung Adenocarcinoma: Role of EBUS and Risk Factors

Abstract Introduction Acquired tracheoesophageal fistulization is a rare occurrence in itself and is typically associated with traumatic iatrogenic complications or localized malignancies, most commonly primary esophageal tumors. EBUS bronchoscopy is a relatively safe diagnostic procedure with few associated risks. This case report will emphasize a discussion of a patient with an untreated adenocarcinoma of the lung developing a tracheoesophageal fistula four months after an EBUS bronchoscopy. Case Presentation A 68-year-old woman with a history of COPD and untreated stage IIIB lung adenocarcinoma, as well as active tobacco use, was admitted in late 2022 with four months of progressive shortness of breath, cough, dysphagia, nausea, vomiting, and anorexia, ultimately diagnosed with a tracheoesophageal fistula (TEF) on videofluoroscopic swallowing study (VFSS). Four months prior, she presented with respiratory symptoms, underwent chest CT revealing mediastinal adenopathy, and subsequently had an EBUS bronchoscopy with FNA of a left paratracheal mass, confirming adenocarcinoma. No endobronchial abnormalities or initial complications were noted. Subsequent admissions were prompted by ongoing respiratory and upper gastrointestinal symptoms. Esophagogastroduodenoscopy initially showed only mild distal esophagitis. Treatment for her lung cancer was delayed due to persistent nausea, vomiting, anorexia, and subsequent significant weight loss. Her condition further deteriorated, presenting with cough productive of food particles, and a new left upper lobe cavitary lesion detected on CT. This prompted initiation of IV antibiotics and a speech therapy referral. TEF was ultimately confirmed on VFSS and follow-up EGD, leading to placement of a percutaneous endoscopic gastrostomy (PEG) tube and esophageal stent at the mid-esophagus for fistula management. Case Discussion In this case, both EBUS bronchoscopy and subsequent EGD were well tolerated without immediate injury, ruling out direct trauma as a cause. The timeline raises key questions regarding the latency between instrumentation and TEF formation, and whether fine-needle aspiration alone can precipitate such a complication. It is plausible that TEF development was multifactorial, influenced by the patient’s active smoking, underlying COPD with chronically inflamed airways, advanced untreated lung cancer, and recurrent episodes of nausea and vomiting. These factors may have collectively increased intrathoracic and esophageal pressures, facilitating fistula formation in the absence of overt procedural trauma. Conclusion This case report highlights possible causes of TEF including baseline risk factors, instrumentation, and suspected infection. As patient’s prognosis grows more oblique and dismal, further research on EBUS related infections should be considered along with TEF risk stratification and early detection and management to improve patient outcomes. This abstract is funded by: none