# Todani — Todani classification of congenital bile duct cysts

> Classifies congenital bile duct cysts by the exact intrahepatic, extrahepatic and intraduodenal segments involved; the code must preserve classical subtypes, mapped anatomy, complications and uncertainty without selecting treatment by itself.

**Situação:** vigente · **Órgão:** Vias biliares · **Órgão emissor:** Todani et al. / hepatopancreatobiliary literature · **Versão:** 1977 original; 2003 anatomic clarification · **Ano:** 1977

> ⚠️ Uma versão mais nova pode existir (em revisão).

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: MRCP, MRI, CT, US, ERCP
- Fonte primária: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/
- Última verificação: 2026-07-24
- Última checagem: 2026-08-12

## Lógica de decisão
Map the complete biliary tree before assigning I-V, preserve Ia/Ib/Ic and IVa/IVb when resolvable, surface complications and uncertainty, and keep the anatomic code separate from diagnosis, patient-specific cancer prediction and treatment selection.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| I | Type I | A solitary congenital cystic or fusiform dilatation of the extrahepatic bile duct without congenital intrahepatic duct ectasia. Preserve subtype when anatomy supports it: Ia involves essentially the entire extrahepatic duct cystically, Ib is focal/segmental, and Ic is diffuse smooth fusiform extrahepatic dilatation. | Complete biliary mapping and hepatopancreatobiliary referral are appropriate. Specialist literature generally favors extrahepatic cyst excision with cholecystectomy and bilioenteric reconstruction when feasible, but age, inflammation, prior intervention, distal duct anatomy and local expertise determine the actual plan. | Complications include cholangitis, pancreatitis, stones, stricture and malignancy. In a 2,904-patient meta-analysis, overall malignancy prevalence across all types was 10.7%, and types I/IV accounted for nearly all reported cancers; this pooled retrospective estimate is not an individual prediction and risk persists after treatment. | Soares et al. 2014, PMC4332770, Classification and Management sections/Figure 1 for Ia-Ic anatomy and type I treatment context; ten Hove et al. 2018, PMC5900735, Results and Tables 2-3 for pooled and type-stratified malignancy. | ✓ |
| II | Type II | A true diverticulum arising from the extrahepatic bile duct through a discrete neck, with the remaining duct otherwise near normal. Distinguish it from a focal type Ib cyst, cystic-duct lesion, gallbladder duplication and adjacent noncommunicating cyst by showing the neck and duct communication. | Specialist assessment commonly considers diverticulectomy; the width and location of the neck and integrity of the parent duct determine primary repair versus biliary reconstruction. The Todani label itself does not select a procedure. | Type II was uncommon in the malignancy meta-analysis and had far less observed cancer than types I/IV. The small type-specific sample and retrospective follow-up do not establish zero malignant risk; obstruction, stones, cholangitis and procedural duct injury remain relevant. | Soares et al. 2014, PMC4332770, Classification, Differential Diagnosis and Management sections for true extrahepatic diverticulum morphology, mimics and excision context; ten Hove et al. 2018, PMC5900735, type-stratified malignancy analysis and sample-size limitations. | ✓ |
| III | Type III (choledochocele) | A choledochocele: cystic dilatation of the intramural/intraduodenal distal common bile duct that protrudes toward the duodenal lumen. Distal duct prominence alone is insufficient; show the ampullary or intraduodenal relationship and distinguish duodenal duplication cyst or periampullary diverticulum. | Symptomatic or complicated lesions may be evaluated for endoscopic sphincterotomy/unroofing or selected surgical treatment according to size, epithelial lining, common-channel anatomy and local expertise. Imaging classification alone must not order intervention. | Reported malignant transformation is lower than for types I/IV, but type III cohorts are small and do not prove absence of risk. Pancreatitis, obstruction, cholangitis and stone formation can occur, and mucosal or mural abnormalities require direct evaluation. | Soares et al. 2014, PMC4332770, Classification, Clinical Differentiation and Management sections for intraduodenal anatomy, differential and endoscopic/surgical context; ten Hove et al. 2018, PMC5900735, type II/III subgroup limitations. | ✓ |
| IV | Type IV | Multiple congenital bile duct dilatations. IVa involves both intrahepatic and extrahepatic ducts; IVb consists of multiple extrahepatic dilatations only. The subtype is mandatory when resolvable, with lobar distribution, dominant intrahepatic strictures and residual drainage anatomy described separately. | IVb commonly follows an extrahepatic excision/reconstruction framework. IVa additionally requires specialist mapping of intrahepatic strictures and burden; selected patients may need hepatic resection, drainage planning or transplant evaluation. The Roman numeral is not an autonomous surgical instruction. | Type IV shares the major malignancy signal with type I and can produce recurrent cholangitis, hepatolithiasis, strictures, cirrhosis and portal hypertension. Residual intrahepatic disease and post-reconstruction anatomy require long-term specialist follow-up; pooled cancer figures must not be individualized mechanically. | Todani et al. 2003, DOI 10.1007/s00534-002-0733-7, pp. 340-344 for IVa/primary-stricture clarification; Soares et al. 2014, PMC4332770, classification and type IV management; ten Hove et al. 2018, PMC5900735, Tables 2-3 for I/IV malignancy predominance. | ✓ |
| V | Type V (Caroli disease) | Congenital communicating segmental saccular or fusiform dilatation confined to the intrahepatic bile ducts (Caroli disease), without an extrahepatic cyst. Caroli syndrome adds congenital hepatic fibrosis and portal-hypertension features, which must be stated because the Todani V code alone does not encode fibrosis. | Localized unilobar disease may be assessed for hepatic resection; diffuse bilateral disease with recurrent cholangitis, portal-hypertension complications or liver failure may prompt transplant evaluation. Infection, stones and obstruction need direct management independent of the code. | Recurrent cholangitis, intrahepatic stones, abscess, fibrosis/cirrhosis and cholangiocarcinoma are important long-term risks. A central-dot sign supports but does not independently prove Caroli disease, and mimics such as PSC, recurrent pyogenic cholangitis and peribiliary cysts must be excluded. | Soares et al. 2014, PMC4332770, Type V/Caroli classification, differential and management sections for intrahepatic-only communication, localized versus diffuse management and complications; ten Hove et al. 2018, PMC5900735, malignancy background and type-distribution discussion. | ✓ |

### Citações por categoria
- **I**: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/ · Soares et al. 2014, PMC4332770, Classification and Management sections/Figure 1 for Ia-Ic anatomy and type I treatment context; ten Hove et al. 2018, PMC5900735, Results and Tables 2-3 for pooled and type-stratified malignancy.
- **II**: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/ · Soares et al. 2014, PMC4332770, Classification, Differential Diagnosis and Management sections for true extrahepatic diverticulum morphology, mimics and excision context; ten Hove et al. 2018, PMC5900735, type-stratified malignancy analysis and sample-size limitations.
- **III**: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/ · Soares et al. 2014, PMC4332770, Classification, Clinical Differentiation and Management sections for intraduodenal anatomy, differential and endoscopic/surgical context; ten Hove et al. 2018, PMC5900735, type II/III subgroup limitations.
- **IV**: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/ · Todani et al. 2003, DOI 10.1007/s00534-002-0733-7, pp. 340-344 for IVa/primary-stricture clarification; Soares et al. 2014, PMC4332770, classification and type IV management; ten Hove et al. 2018, PMC5900735, Tables 2-3 for I/IV malignancy predominance.
- **V**: Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst (1977) — https://pubmed.ncbi.nlm.nih.gov/889044/ · Soares et al. 2014, PMC4332770, Type V/Caroli classification, differential and management sections for intrahepatic-only communication, localized versus diffuse management and complications; ten Hove et al. 2018, PMC5900735, malignancy background and type-distribution discussion.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2026-08-01 | revised | Monitored source changed (version_regex). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-24 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2003-10-01 | revised | Todani and colleagues clarified type Ic and type IVa anatomy, including primary ductal strictures, without replacing the classical I-V framework. | confirmed |
| 1977-08-01 | published | Todani and colleagues published the expanded congenital bile duct cyst classification and operative anatomy in the American Journal of Surgery. | confirmed |


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> Conteúdo de referência reescrito. Confira a publicação primária vigente. Não é dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

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