Endoscopic ultrasonography for differential diagnosis of polypoid gall bladder lesions: analysis in surgical and follow up series

Background-Differential diagnosis is often difficult for small (less than o r equal to 20 mm) polypoid lesions of the gall bladder. Aim--To assess the diagnostic accuracy of endoscopic ultrasonography (EUS) for polypoid lesion s in a surgical and follow up series. Methods--A total of 194 patients with small polypoid lesions underwent both ultrasonography and EUS. A tiny echogenic spot or an aggregation of echoge nic spots and multiple microcysts or a comet tail artefact indicated choles terol polyp and adenomyomatosis respectively. Other lesions were diagnosed as neoplastic (adenoma or adenocarcinoma). In the 58 patients who underwent surgery, the histological diagnoses were cholesterol polyp (n = 36), adeno myomatosis (n = 7), adenoma (n = 4), and adenocarcinoma (n = 11). Of the re maining 136 patients with an EUS diagnosis of non-neoplastic lesions, 125 w ere followed up with ultrasonography alone or with EUS for 1-8.7 years (mea n 2.6 years). Results--In the surgical series, EUS (97%) differentiated polypoid lesions more precisely than ultrasonography (76%). During follow up, the lesions re mained unchanged in size in 109 (87%) of the 125 patients with non-neoplast ic lesions diagnosed by EUS. No neoplastic lesions developed in these patie nts. Ultrasonopraphy had shown lesions to be neoplastic in 13% of the follo w up series. Conclusions--EUS is highly accurate for differentially diagnosing polypoid gall bladder lesions. It is recommended when ultrasonography cannot rule ou t neoplastic lesions. Non-neoplastic lesions diagnosed by EUS may be follow ed and observed with ultrasonography.