Low-Grade Dysplastic Intracholecystic Papillary Neoplasia: A Case Report.

BACKGROUND The World Health Organization classification of premalignant gallbladder lesions includes adenomas, intraductal papillary neoplasms, biliary intraepithelial neoplasia, and intracystic papillary neoplasms. Noninvasive neoplastic lesions >1 cm that originate from the pancreatobiliary system are defined as intraductal papillary neoplasia when they occur in the biliary ducts. The clinical and pathological features of preinvasive lesions arising in the gallbladder are not yet well defined. However, the most widely accepted classification is that of intracholecystic papillary neoplasm (ICPN). CASE REPORT We present the case of a 71-year-old woman referred to a General Surgery outpatient clinic for suspicious findings on imaging of the gallbladder, namely irregular infundibular parietal thickening. The patient underwent a laparoscopic cholecystectomy and histological examination revealed a thickened gallbladder with mucosa partially surrounded by ICPN with an intestinal pattern and some foci of low-grade dysplasia but no foci of high-grade dysplasia or invasive neoplasia. At follow-up at 30 months, the patient remains clinically well, with no changes visible on computed tomography scan. CONCLUSIONS ICPN of the gallbladder appears to be part of a spectrum of alterations encompassing bile duct or pancreatic lesions. Although it is uncommon, more than half of the lesions are known to have foci of invasive neoplasia at the time of diagnosis. Despite that, the prognosis for these neoplasms is more favorable than for gallbladder neoplasia that originates from another type of lesion. Pathological study of ICPN is essential to define the main characteristics that impact prognosis and survival in these patients.