4 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Dysplasia means the cells lining the gallbladder have become abnormal but have not invaded; carcinoma in situ (stage 0) is the most abnormal form, with cancer cells still confined to the lining. Both are found by the pathologist after a gallbladder is removed and are cured by that removal when the margin is clear. Cancer Research UK notes some doctors do not regard stage 0 as a true cancer.
Gallbladder cancer develops through a metaplasia, dysplasia, carcinoma sequence in chronically inflamed mucosa (Lewis 2007; Hundal 2014). The WHO classification (5th edition, 2019; Nagtegaal 2020) names the flat precursor biliary intraepithelial neoplasia, graded low or high, with high-grade lesions equivalent to carcinoma in situ, and the mass-forming precursor the intracholecystic papillary neoplasm (Adsay 2012). In TNM 8th edition carcinoma in situ is Tis, stage 0: cancer cells confined to the lining with no invasion, rarely found except when a gallbladder is removed for other reasons (CRUK stages and grades). Early carcinomas confined to or above the muscle layer (Tis, T1a, T1b) are usually invisible to the naked eye (60 percent of 190 cases), occur about a decade younger than advanced cancers (mean 57.9 years) and have excellent outcomes: 92.3 percent five-year and 90.4 percent ten-year survival in a high-incidence series that sampled every specimen fully. The exception is extension of the intraepithelial tumour into Rokitansky-Aschoff sinuses, present in 17.8 percent, after which 39 percent died of disease against 4 percent without, often years later (Roa 2013). In primary sclerosing cholangitis dysplasia and carcinoma are common enough (37 and 14 percent of explanted gallbladders) that guidelines advise cholecystectomy for any polyp; a later cohort found most such polyps benign and proposed short-interval surveillance before surgery in the absence of high-risk features (Lewis 2007; van Erp 2020).
What differs in treatment: Tis with a clear cystic duct margin needs no operation beyond the cholecystectomy already done. A positive cystic duct margin, or high-grade dysplasia running into the cystic duct, prompts consideration of bile duct margin re-excision, and Rokitansky-Aschoff sinus involvement is a reason to consider further surgery and to follow the patient for years (Roa 2013). The pathology protocol matters: at least three sections and the cystic duct margin from every routine specimen in high-incidence settings, and complete embedding when dysplasia or cancer is found (Aloia 2015).
| Setting | Approach | Guideline |
|---|---|---|
| Tis or dysplasia with a clear cystic duct margin | No further surgery; follow-up because occasional late recurrences reflect a field effect. | not mapped |
| Positive cystic duct margin or Rokitansky-Aschoff sinus involvement | Consider bile duct margin re-excision or further surgery at a hepatobiliary centre. | not mapped |
| Gallbladder polyp in primary sclerosing cholangitis | Cholecystectomy advised for polyps of any size by international guidelines; a 2020 cohort supports short-interval imaging first when no high-risk feature is present. | not mapped |