RARE BRONCHOESOPHAGEAL FISTULA IN CROHN'S DISEASE: A RADIOLOGICAL PERSPECTIVE:

INTRODUCTION:
Crohn's disease (CD) is an idiopathic inflammatory bowel disease that most often involves the ileum and colon. Esophageal disease is rare, affecting 0.2%-1.8% of symptomatic adults, and can lead to stricture, pseudopolyps, and, rarely, fistula formation. Bronchoesophageal fistula (BEF) is an exceedingly uncommon complication, with fewer than 20 reported cases. We present a case of CD complicated by BEF and pulmonary abscess, emphasizing diagnostic imaging findings.

CASE INFORMATION:
A 71-year-old woman with CD, diabetes, and hypertension presented with fatigue, cough, fever, chills, and pleuritic chest and epigastric pain. She described months of malaise, dysphagia, exertional dyspnea, and weight loss. Exam revealed decreased breath sounds and rhonchi at the left lung base. Laboratory studies showed leukocytosis and lactic acidosis. CT chest and abdomen demonstrated a large loculated pleural collection with air-fluid levels consistent with pulmonary abscess and extraluminal oral contrast extravasation concerning for esophageal perforation. Endoscopy revealed chronic esophagitis with a benign pseudo polyp, mid esophageal stricture, and a fistula versus contained perforation. A covered esophageal stent was placed, and subsequent esophagogram showed no active leak. Despite the presence of a large pulmonary abscess, the patient declined interventional drainage and was discharged. On follow-up, CT revealed resolution of the pulmonary abscess but persistent features of BEF. Later stent removal demonstrated distal esophageal polyps, stricture, and raw mucosa at the suspected fistula site. Five months later, repeat contrast esophagogram confirmed a persistent tract between the distal esophagus and a left basilar bronchus, with irregular mucosa and a thoracic stricture.

DISCUSSION:
In adults, BEFs are typically acquired from malignancy, infection, trauma, or surgery; CD is a rare cause. Radiologic evaluation is central to diagnosis. Contrast esophagography remains the initial study, with the hallmark finding of contrast extravasation into the tracheobronchial tree. However, small or intermittently patent tracts may be missed. CT provides critical complementary information: direct visualization of the fistulous tract in many cases, as well as indirect signs such as mediastinal inflammation, endobronchial debris, aspiration changes, and associated abscesses. CT also guides surgical planning by delineating fistula extent and adjacent complications. Endoscopy confirms mucosal disease and allows for biopsy or therapeutic intervention. Management of BEF is complex. Esophageal stents can reduce aspiration but rarely provide durable closure. While anti-TNF agents and immunomodulators are established in other fistulizing CD, evidence for esophageal fistulas is limited to case reports. Endoscopic sealants, including Onyx polymer, have been reported in refractory cases, though esophagectomy with gastric pull-through remains the most definitive treatment. Our patient demonstrates the limited durability of medical or endoscopic therapy and the key role of radiology in both initial detection and longitudinal assessment.

CONCLUSION:
BEF is a rare but serious complication of CD. Radiology is essential for diagnosis, with CT and contrast esophagography together providing complementary evidence of fistulae and complications. While medical and stent-based therapies may palliate symptoms, surgery remains the most reliable treatment for refractory disease. Early recognition and multidisciplinary collaboration are critical for optimal outcomes.