2025 Volume 39 Issue 2 Pages 211-219
The patient was a 66-year-old woman. A gallbladder polyp was detected 11 years ago and was followed up, but it showed a tendency to increase in size. An endoscopic ultrasonography revealed a papillary lesion 11mm in diameter with high echo spots at the neck of the gallbladder, and a cholesterol polyp was suspected. Since the size of the lesion was more than 10mm and malignancy could not be ruled out, a laparoscopic cholecystectomy was performed. A 10 × 7 × 5mm stalked, protruding lesion was found at the neck of the gallbladder. Histopathological examination revealed a papillary growth of columnar epithelium centered on a narrow vascular fibrous stroma. The nuclei were spindle-shaped and arranged in the basement membrane, and the lesion was diagnosed as intracholecystic papillary neoplasm (ICPN) with low-grade dysplasia. ICPN is a precancerous lesion and many cases are accompanied by invasive carcinoma. ICPN without carcinoma like our case is extremely rare and is difficult to differentiate between malignant and benign disease.
