Management of incidental pancreatic cysts: which guidelines?

Abstract

Medicine is not a perfect science. That is no truer than in the evaluation and management of the asymptomatic pancreatic cyst. Ever more common, these cystic lesions frustrate gastro-enterologists, surgeons and patients alike. Existing consensus statements and societal guidelines have been based upon ex-pert opinion and little evidence, frequently leaving physicians who care for these patients with more questions than answers. The recent American Gastroenterological Association (AGA) guidelines, which many view as controversial, have continued to stir this pot. From a historical perspective, pancreatic cyst guidelines have continued to evolve over the last decade. The first guide-lines (American Society for Gastrointestinal Endoscopy, 2005) recommended endoscopic ultrasound-guided fine-needle as-piration (EUS-FNA) of all cysts for cyst fluid analysis and cytolo-gy [1]. The Sendai guidelines (International Association of Pan-creatology, 2006) specifically addressed Intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, and called for more selective use of EUS based on cyst size and pres-ence of worrisome features [2]. The updated Fukuoka guide-lines (International Association of Pancreatology, 2012) similar-ly recommended the presence of a worrisome feature for eval-uation by EUS; cyst size became less of a concern. Worrisome features include cyst size size ≥ 30 mm, enhanced thickened cyst walls, non-enhanced mural nodules, main pancreatic duct (MPD) size 5 to 9 mm, abrupt change in MPD caliber with distal glandular atrophy, and lymphadenopathy. Criteria for surgical referral according to the Fukuoka guidelines are any high-risk stigmata which include obstructive jaundice in the setting of a pancreatic head cyst, presence of a mural nodule/solid compo-nent, MPD ≥ 10 mm or cytology suspicious or positive for malig-nancy [3]. The current AGA guidelines (2015) deal with man-agement of asymptomatic cysts, without regard to cyst type. They recommend the presence of 2 high-risk stigmata (cyst size size ≥ 30 mm, dilated MPD, solid component) before an EUS examination be performed. For surgical referral, the AGA guidelines require malignant cytology on EUS-FNA or at least 2 high-risk features (cyst size size ≥ 30 mm, dilated MPD, solid component)[4]. Thus, with time and knowledge, guidelines have become more conservative with the recognition that the malignant risk of an asymptomatic cyst is very low. Accordingly, magnetic resonance imaging (MRI) for surveillance is increas-ingly recommended. In this edition of Endoscopy International Open, 2 articles pour more gas on the fire. Lee et al.'s retrospective 2-part study evaluates and compares the operating characteristics of the AGA and Fukuoka guidelines for detection of and surgical refer-ral for malignant pancreatic cysts [5]. An EUS database was used to determine appropriateness for EUS referral of a MRI-de-tected asymptomatic cyst (n = 143) based on criteria for such according to the 2 sets of guidelines. For EUS detection of a high-risk cyst (HGD or carcinoma), the Fukuoka guidelines were more sensitive (33.3 % vs 16.7 %) but less specific (65.4 % vs 94.4 %) compared to the AGA guidelines. This is no surprise given the guidelines' criteria for EUS referral. Twenty three cysts were referred for surgery based on EUS findings; 7 were malignant or harbored HGD. Using definitive cytology and/or surgical histology, based on AGA guidelines, 5 of the 7 (71.4 %) high-risk cysts did not meet criteria for EUS referral, where 3 of 7 (42.9 %) did not meet criteria by the Fukuoka guidelines. The second part of the study analyzed the guidelines for re-ferral to surgical resection utilizing a pathology database of re-sected asymptomatic cysts (n = 152) that had undergone MRI and EUS. Based on criteria for surgical referral, the performance characteristics did not differ statistically between the guide-lines; 30.9 % and 36.2 % of patients would have been referred by the AGA and Fukuoka guidelines, respectively. For high-risk cysts based on surgical pathology (n = 17), 5 of 17 (29.4 %) did not meet surgical criteria by AGA guidelines; 3 of these 17 (17.6 %) did not meet criteria by Fukuoka guidelines.