EUS-FNA for patients with suspected malignant biliary strictures after negative results by endoscopic transpapillary brush cytology or forceps biopsy

Background: Endoscopic transpapillary brush cytology or forceps biopsy is widely used for patients with suspected malignant biliary strictures. However, since the sensitivity of these methods remain insufficient, it is sometimes difficult to confirm the diagnosis of malignancy. In such cases, alternative sampling techniques are required for providing a definitive diagnosis that will aid in choosing a treatment strategy.

Aims: This study aimed to evaluate the results of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and its impact on patient management in the case of patients with suspected malignant biliary strictures and for whom endoscopic transpapillary brush cytology or forceps biopsy had yielded negative results.

Methods: Between December 2007 and December 2009, 225 patients with suspected malignant biliary strictures had undergone endoscopic transpapillary brush cytology and/or forceps biopsy at our institutions. Negative results were obtained for pathological tests in 75 patients, and EUS-FNA was performed in 22 of these 75 patients. In this study, we retrospectively compared the EUS-FNA results of these 22 patients with their final diagnosis and examined the influence of the EUS-FNA results on the treatment strategy for these patients.

Results: In 19 patients, EUS-FNA revealed the presence of a mass at the stricture site; the median value for the largest diameter of such masses was 29mm (range: 7-61mm). In 3 patients, only thickening of the wall of the bile duct was observed, and the thickened wall was punctured in such cases. Pathological specimens were successfully obtained for all patients, and the results of the pathological tests confirmed the presence of malignancies in 16 patients and indicated suspected benign diseases in 6 patients. Pathological examination of the surgically resected specimens made a diagnosis of xanthogranulomatous cholecystitis in 3 of the 6 cases where EUS-FNA results indicated suspected benign diseases. The 3 remaining patients were diagnosed as having benign diseases at 8, 14, and 16 months during long-term follow-up. Ultimately, the EUS-FNA-based diagnosis was proven correct for all the patients. In addition, the treatment strategy was altered due to EUS-FNA results in at least 6 patients (27%). EUS-FNA-related complications did not occur in any of the patients.

Conclusions: We concluded that EUS-FNA is a sensitive and safe method for patients suspected to have malignant biliary strictures and should be used in cases where endoscopic transpapillary brush cytology and/or forceps biopsy has yielded negative results.