Pathological survey of precursor lesions in cholangiocarcinoma

Intraductal Polypoid Neoplasm in the Intrahepatic Large Bile Ducts of Small Duct-type Intrahepatic Cholangiocarcinoma May Result From Cancerization of Ducts

To survey and characterize intraductal polypoid neoplasms in the intrahepatic large bile ducts of small duct-type intrahepatic cholangiocarcinoma (small duct-iCCA), a total of 121 cases of small duct-iCCA presenting mass-forming growth were surveyed for intraductal polypoid neoplasms that were compared with mass-forming tumors in individual cases and with intraductal papillary neoplasm of bile duct (IPNB) (20 cases). Polypoid neoplasms were found in intrahepatic bile ducts in 8 (6.6%) of 121 cases of small duct-iCCA. They showed cast-like growth involving several adjoining bile ducts adjacent to or in the peripheries of mass-forming tumors as well as well-differentiated papillary or tubular/cribriform patterns and no stromal invasion. Intraductal polypoid neoplasms were histologically and immunohistochemically similar to mass-forming tumors in individual cases, and both components were of biliary subtype. There was an abrupt transition between these polypoid neoplasms and normal lining epithelia in the affected bile ducts, suggesting that intraductal polypoid neoplasms reflect the cancerization of ducts. IPNB presented with biliary (5 cases), intestinal (8 cases), gastric (5 cases), and oncocytic subtypes (2 cases), and about half of IPNBs were noninvasive, thus differing from intraductal polypoid neoplasms of small duct-iCCA. In conclusion, small duct-iCCA occasionally presents as intraductal polypoid neoplasms in adjoining bile ducts, reflecting the cancerization of ducts. These intraductal polypoid neoplasms should be considered in the differential diagnosis of heterogeneous intraductal tumors of bile ducts.

Pathologic characterization of precursors and cholangiocarcinoma referring to peribiliary capillary plexus: a new pathologic approach to bile duct neoplasm

The peribiliary capillary plexus (PCP) regularly and densely lines the basal side of the lining epithelia of normal bile ducts. To determine the pathology of the PCP in high-grade biliary intraepithelial neoplasms (BilINs) and intraductal papillary neoplasms of the bile duct (IPNBs), a precursor of cholangiocarcinoma (CCA), and CCA. Seventy-six cases of surgically resected high-grade BilIN and 83 cases of IPNB were histopathologically examined using endothelial immunostaining of PCP; all cases of high-grade BilIN and 40 cases of IPNB were associated with invasive CCA. Invasive and preinvasive neoplasms were pathologically examined referring to a two-layer pattern composed of biliary lining epithelia and underlying PCP unique to the bile duct. All high-grade BilIIN cases had an underlying single layer of capillaries, similar to PCP (PCP-like capillaries). In 43% of the 83 cases of IPNB, these capillaries were regularly distributed in almost all stalks and intervening stroma of intraluminal neoplastic components, while in the remaining 57% of IPNB, capillaries were sparsely or irregularly distributed in intraluminal components showing cribriform or solid growth patterns composed of striking atypical neoplastic epithelia. Invasive carcinomas associated with high-grade BilIN and IPNB were not lined with capillaries. The loss of PCP-like capillaries underlying high-grade BilIN and in stalks or stroma of IPNB may be involved in the malignant progression of these precursors. Immunostaining of PCP could be a new pathological tool for the evaluation of malignant progression and vascular supply in CCA and its precursors.

Residual biliary intraepithelial neoplasia without malignant transformation at resection margin for perihilar cholangiocarcinoma does not require expanded resection: a dual center retrospective study

BACKGROUND

Additional resection for invasive cancer at perihilar cholangiocarcinoma (pCCA) resection margins has become a consensus. However, controversy still exists regarding whether additional resection is necessary for residual biliary intraepithelial neoplasia (BilIN).

METHOD

Consecutive patients with pCCA from two hospitals were enrolled. The incidence and pattern of resection margin BilIN were summarized. Prognosis between patients with negative margins (R0) and BilIN margins were analyzed. Cox regression with a forest plot was used to identify independent risk factors associated with overall survival (OS) and recurrence-free survival (RFS). Subgroup analysis was performed based on BilIN features and tumor characteristics.

RESULTS

306 pCCA patients receiving curative resection were included. 255 had R0 margins and 51 had BilIN margins. There was no significant difference in OS (P = 0.264) or RFS (P = 0.149) between the two group. Specifically, 19 patients with BilIN at distal bile ducts and 32 at proximal bile ducts. 42 patients showed low-grade BilIN, and 9 showed high-grade. Further analysis revealed no significant difference in long-term survival between different locations (P = 0.354), or between different grades (P = 0.772). Portal vein invasion, poor differentiation and lymph node metastasis were considered independent risk factors for OS and RFS, while BilIN was not. Subgroup analysis showed no significant difference in long-term survival between the lymph node metastasis subgroup, or between the portal vein invasion subgroup.

CONCLUSION

For pCCA patients underwent curative resection, residual BilIN at resection margin is acceptable. Additional resection is not necessary for such patients to achieve absolute R0 margin.

Interobserver agreement of pathologic classification and grading of tumoral intraductal pre-invasive neoplasms of the bile duct

Current WHO terminology and recent publications have classified tumoral (grossly visible) intraductal pre-invasive neoplasms of bile duct (TIDN) into three categories: intraductal papillary neoplasm of bile duct (IPNB), intraductal papillary oncocytic neoplasm (IOPN), and intraductal tubulopapillary neoplasm (ITPN). A total of 227 cases of TIDN and related lesions ≥3 mm in height were examined by 10 biliary pathologists referring to these 3 categories and two pathologic gradings: two-tiered system (low- and high-grade dysplasia) and modified types 1 and 2 subclassification. Among them, IPNB was the most frequent (183 cases), followed by IOPN (28 cases), while ITPN was rare (2 cases), and interobserver agreement in this classification was "substantial" (κ-value, 0.657). The interobserver agreement of two-tiered grading system of TIDN was "slight" (κ-value, 0.201), while that of modified types 1 and 2 subclassification was "moderate" (κ-value, 0.515), and 42 % were of type 1, and 58 % were of type 2. Type 1 TIDN showed occasional stromal invasion (6.7 %), whereas type 2 TIDN was frequently associated with stromal invasion (49.6 %) (p < 0.01). In conclusion, the classification of TIDN into three categories and modified types 1 and 2 subclassification are a practically applicable classification and grading system for TIDN.

Current considerations on intraductal papillary neoplasms of the bile duct and pancreatic duct

Pancreatobiliary intraductal papillary neoplasms (IPNs) represent precursors of pancreatic cancer or bile duct cholangiocarcinoma that can be detected and treated. Despite advances in diagnostic methods, identifying these premalignant lesions is still challenging for treatment providers. Modern imaging, biomarkers and molecular tests for genomic alterations can be used for diagnosis and follow-up. Surgical intervention in combination with new chemotherapeutic agents is considered the optimal treatment for malignant cases. The balance between the risk of malignancy and any risk of resection guides management policy; therefore, treatment should be individualized based on a meticulous preoperative assessment of high-risk stigmata. IPN of the bile duct is more aggressive; thus, early diagnosis and surgery are crucial. The conservative management of low-risk pancreatic branch-duct lesions is safe and effective.

Identification of neutrophil-related genes and development of a prognostic model for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is a prevalent gastrointestinal tumor with limited effective early diagnostic methods. The role of neutrophils in the context of cholangiocarcinoma remains largely unexplored.

METHODS

A comprehensive analysis was performed on a cohort of cholangiocarcinoma samples (TCGA-CHOL) from the TCGA database to investigate the relationship between cholangiocarcinoma and neutrophils. Methodologies included single-sample gene set enrichment analysis (ssGSEA), differential expression analysis, weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA).

RESULTS

The study identified a significant decrease of neutrophils in cholangiocarcinoma via ssGSEA. WGCNA and differential expression analysis led to the identification of a neutrophil-related gene module comprised of 1059 genes. Cluster 1, showing a higher proportion of neutrophils, was linked to better survival outcomes. GSEA disclosed downregulation of complement, inflammatory response and interferon response pathways in Cluster 2, hinting at possible cholangiocarcinoma development triggers. A notable upregulation of PD1, PD-L1 and CTLA4 was observed in Cluster 1, suggesting potential benefits from immunotherapy. A prognostic model was developed based on clinical data and expression levels of three prognostic genes (SOWAHD, TNFAIP8 and EBF3) showing satisfactory discrimination, calibration and clinical benefits. An overexpression of TNFAIP8 in cholangiocarcinoma cells was found, with its knockdown significantly inhibiting cell proliferation and migration.

CONCLUSIONS

This study elucidates a neutrophil-related gene module and prognostic genes, offering insights into the role of neutrophils in cholangiocarcinoma development and progression. It also introduces a clinical prediction model for enhanced prognosis assessment. These findings may lay the groundwork for the development of innovative therapeutic strategies in cholangiocarcinoma treatment.