Adenomatous (Dysplastic) Transformation in Cholesterol Polyps (CPs) of the Gallbladder (GB)
Burcu Saka, Pelin Bagci, Nevra Dursun, Olca Basturk, Juan C Roa, Kee-Taek Jang, Oscar Tapia, Hector Losada, Juan Sarmiento, Takuma Tajiri, Volkan Adsay. Emory University, Atlanta, GA; Memorial Sloan-Kettering Cancer Center, New York, NY; Pontificia University, Santiago, Chile; SMC, Seoul, Korea; U Frontera, Temuco, Chile; Tokai University, Tokyo, Japan
Background: CPs of the GB are common incidental findings, and regarded as innocuous lesions with no significance. In fact, it has been speculated that cholesterolosis may be protective against neoplastic change; numerous studies have found that cholesterolosis correlate inversely with carcinoma in the GB.
Design: Histology of 394 polypoid lesions of the GB were reviewed.
Results: 13 cases of CP with adenomatous (dysplastic) transformation were identified, all showing dysplastic transformation almost exclusively within the polyp. Male to female ratio was 6:7, with a mean polyp size of 1.14 cm (0.2-5), and 9 were ≥1 cm. The mean age was 61(as opposed to 49 yrs for those CPs without neoplastic change). In 4, the dysplastic changes were focal (<25% of the polyp), in 1, substantial (25-75%) and in 8, diffuse. All lesions were recognizable by the distinctive architecture characteristic of CPs, in addition to clusters of cholesterol laden macrophages within the polyp stroma. Uninvolved GB revealed cholesterolosis in only 3/13. Only 1 had any significant cholecystitis in the background. 3 were associated with invasive ca in the same GB.
A. Bulk of the lesion was otherwise classical CP but there were foci of dysplastic transformation within the lesion.
B. Bulk of the lesion was ordinary neoplastic polyp (intracholecystic papillary tubular neoplasm) but, in some foci, the underlying CP was evident.
Conclusions: This study reveals a hitherto unrecognized phenomenon of neoplastic transformation in CPs. This appears to be an age-related progression phenomenon. Also, in all cases with diffuse dysplasia, CPs were ≥1 cm, supporting the current practice of 1 cm criteria for cholecystectomy. These cases further illustrate the propensity of the proliferative GB epithelium to develop into neoplasia, thus lends further support to the well-known injury-cancer association in the GB.
Tuesday, March 5, 2013 9:30 AM
Poster Session III # 202, Tuesday Morning