# Cystic duct carcinoma

Source: https://onco.cc/cancers/cystic-duct-carcinoma/  
OnCo record `cystic-duct-carcinoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cystic duct carcinoma is a bile duct cancer arising in the short tube that joins the gallbladder to the main bile duct. It is staged as a gallbladder cancer under the AJCC system, and behaves better when it stays inside the duct than when it grows beyond it. It is so rare that its treatment borrows from gallbladder and bile duct cancer.

## Summary

The cystic duct runs from the gallbladder neck to the common hepatic duct. Cancers arising here have been classified sometimes with the extrahepatic bile ducts and sometimes with the gallbladder; the AJCC staging manual has placed the cystic duct in the gallbladder chapter since its 7th edition (2010) (Prasoon 2019), and the WHO classification covers the gallbladder and extrahepatic bile ducts in one chapter. A 2025 Korean study compared 38 cystic duct cancers with 345 gallbladder and 349 distal bile duct cancers: overall survival did not differ between the three, the gallbladder T categories separated survival in cystic duct cancer better than the bile duct categories did, and tumours confined within the duct (Nakata type 1) did significantly better than those extending beyond it, leading the authors to propose a two-tier T category (T1 confined to the duct, T2 beyond it) (Kim 2025). Cancers can also arise in the cystic duct remnant years after cholecystectomy; jaundice, haemobilia and positive bile cytology led to the diagnosis in one reported case, staged pT1b N0 after bile duct resection (Prasoon 2019).

What differs in treatment: the tumour sits at the junction with the common duct, so resection usually means excision of the extrahepatic bile duct with hepaticojejunostomy and regional lymphadenectomy, often with the gallbladder and liver bed as in a radical cholecystectomy, and the cystic duct margin of any gallbladder specimen is where such a tumour is first suspected. Systemic treatment follows the biliary tract cancer trials. No trial has studied cystic duct cancer on its own.

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Cystic duct cancer; Carcinoma of the cystic duct; Remnant cystic duct carcinoma
- Tags: gallbladder; biliary; subtype-page
- Group: gastrointestinal
- Burden: Very rare: 38 cases against 345 gallbladder and 349 distal bile duct cancers in the Korean series that defined its staging (Kim 2025); only a handful of cancers arising in the remnant cystic duct after cholecystectomy have ever been reported (Prasoon 2019).
- Subtypes: Cystic duct carcinoma confined within the cystic duct (Nakata type 1; better survival); Cystic duct carcinoma extending to the gallbladder neck or common bile duct (Nakata types 2 to 4); Carcinoma arising in the remnant cystic duct after cholecystectomy
- Biomarkers: Extent: confined to the duct or beyond it; T category by the gallbladder scheme; Bile duct margin status; Bile cytology in remnant duct cancer

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/cystic-duct-carcinoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/cystic-duct-carcinoma/#overview
- Types and stages (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/cystic-duct-carcinoma/#what-it-is [3 subtypes]
- Symptoms and diagnosis (on the hub): How this cancer shows itself, how the diagnosis is confirmed, and the biomarkers clinicians test for. https://onco.cc/cancers/cystic-duct-carcinoma/#finding-it [4 biomarkers]
- Treatment (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/cystic-duct-carcinoma/#treating-it [2 settings, 1 decision with options]
- Trials and papers (on the hub): Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/cystic-duct-carcinoma/#evidence
- Biology and targets (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/cystic-duct-carcinoma/#science [2 targets]
- Countries and centres (own page): Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes. https://onco.cc/cancers/cystic-duct-carcinoma/where-you-are/
- Decisions and support (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/cystic-duct-carcinoma/#living-with-it [9 questions, 4 red cards]
- Pipeline and open problems (own page): Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/cystic-duct-carcinoma/coming/ [3 medicines]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/cystic-duct-carcinoma/data/ [16 connected records]

## Standard of care

- Resectable disease: Extrahepatic bile duct resection with regional lymphadenectomy, with cholecystectomy and liver bed resection as for radical cholecystectomy when the gallbladder is still present. ([Radical (extended) cholecystectomy](https://onco.cc/terms/radical-cholecystectomy/), [Lymphadenectomy (lymph node dissection)](https://onco.cc/terms/lymphadenectomy/), [Cystic duct margin](https://onco.cc/terms/cystic-duct-margin/), [Biliary stenting and drainage](https://onco.cc/technologies/biliary-stenting-drainage/))
- Advanced disease: As for biliary tract cancer. ([Gemcitabine + cisplatin](https://onco.cc/drugs/gemcitabine-cisplatin/), [Durvalumab](https://onco.cc/drugs/durvalumab/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Cystic_duct
- Kim, Cancer Res Treat 2025: stage evaluation of cystic duct cancer: https://doi.org/10.4143/crt.2024.660
- Prasoon, BMC Surg 2019: remnant cystic duct adenocarcinoma, with the AJCC history of cystic duct staging: https://doi.org/10.1186/s12893-019-0647-9
- Nagtegaal, Histopathology 2020: the 2019 WHO classification of tumours of the digestive system: https://doi.org/10.1111/his.13975

## Connected records

- cancers: [Biliary tract cancer (cholangiocarcinoma)](https://onco.cc/cancers/cholangiocarcinoma/), [Extrahepatic cholangiocarcinoma (perihilar and distal)](https://onco.cc/cancers/extrahepatic-cholangiocarcinoma/), [Gallbladder cancer](https://onco.cc/cancers/gallbladder/), [Incidental gallbladder cancer (found after cholecystectomy)](https://onco.cc/cancers/incidental-gallbladder-cancer/)
- terms: [Cystic duct margin](https://onco.cc/terms/cystic-duct-margin/), [Intrahepatic, perihilar, distal and gallbladder cancer](https://onco.cc/terms/biliary-anatomy-subtypes/), [Lymphadenectomy (lymph node dissection)](https://onco.cc/terms/lymphadenectomy/), [Obstructive jaundice and biliary obstruction](https://onco.cc/terms/obstructive-jaundice/), [Radical (extended) cholecystectomy](https://onco.cc/terms/radical-cholecystectomy/)
- technologies: [Biliary stenting and drainage](https://onco.cc/technologies/biliary-stenting-drainage/)
- drugs: [Durvalumab](https://onco.cc/drugs/durvalumab/), [Gemcitabine + cisplatin](https://onco.cc/drugs/gemcitabine-cisplatin/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)

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JSON: https://onco.cc/api/v1/entities/cystic-duct-carcinoma.json