Spatial transcriptomics profiling of gallbladder adenocarcinoma: a detailed two-case study of progression from precursor lesions to cancer.

BACKGROUND: Most studies on tumour progression from precursor lesion toward gallbladder adenocarcinoma investigate lesions sampled from distinct patients, providing an overarching view of pathogenic cascades. Whether this reflects the tumourigenic process in individual patients remains insufficiently explored. Genomic and epigenomic studies suggest that a subset of gallbladder cancers originate from biliary intraepithelial neoplasia (BilIN) precursor lesions, whereas others form independently from BilINs. Spatial transcriptomic data supporting these conclusions are missing. Moreover, multiple areas with precursor or adenocarcinoma lesions can be detected within the same pathological sample. Yet, knowledge about intra-patient variability of such lesions is lacking. METHODS: To characterise the spatial transcriptomics of gallbladder cancer tumourigenesis in individual patients, we selected two patients with distinct cancer aetiology and whose samples simultaneously displayed multiple areas of normal epithelium, BilINs and adenocarcinoma. Using GeoMx digital spatial profiling, we characterised the whole transcriptome of a high number of regions of interest (ROIs) per sample in the two patients (24 and 32 ROIs respectively), with each ROI covering approximately 200 cells of normal epithelium, low-grade BilIN, high-grade BilIN or adenocarcinoma. Human gallbladder organoids and cell line-derived tumours were used to investigate the tumour-promoting role of genes. RESULTS: Spatial transcriptomics revealed that each type of lesion displayed limited intra-patient transcriptomic variability. Our data further suggest that adenocarcinoma derived from high-grade BilIN in one patient and from low-grade BilIN in the other patient, with co-existing high-grade BilIN evolving via a distinct process in the latter case. The two patients displayed distinct sequences of signalling pathway activation during tumour progression, but Semaphorin 4 A (SEMA4A) expression was repressed in both patients. Using human gallbladder-derived organoids and cell line-derived tumours, we provide evidence that repression of SEMA4A promotes pseudostratification of the epithelium and enhances cell migration and survival. CONCLUSION: Gallbladder adenocarcinoma can develop according to patient-specific processes, and limited intra-patient variability of precursor and cancer lesions was noticed. Our data suggest that repression of SEMA4A can promote tumour progression. They also highlight the need to gain gene expression data in addition to histological information to avoid understimating the risk of low-grade preneoplastic lesions.

Diagnostic guide for immune checkpoint inhibitor-induced liver injury.

With the widespread use of immune checkpoint inhibitors (ICIs), liver injury (ICI-induced liver injury) as an immune-related adverse event has become a major concern in clinical practice. Because severe cases of liver injury require administration of corticosteroids, a comprehensive evaluation is crucial, including clinical course, blood and imaging tests, and if necessary, pathological examination through liver biopsy. As with liver injury induced by other drugs, classification of injury type by R-value is useful in deciding treatment strategies for ICI-induced liver injury. Histologically, the most representative feature is an acute hepatitis-like hepatocellular injury, characterized by diffuse lobular inflammation accompanied by CD8-positive T lymphocytes. Another condition that can cause liver injury during ICI treatment is cholangitis accompanied by non-obstructive bile duct dilatation and bile duct wall thickening. Many cases of ICI-induced cholangitis are classified as non-hepatocellular injury type, and they have been reported to respond poorly to corticosteroids. It is essential that gastroenterologists/hepatologists and doctors in various departments work in cooperation to develop a system that achieves early diagnosis and appropriate treatment of ICI-induced liver injury.

Intrahepatic cholangiocarcinoma: histological diversity and the role of the pathologist.

Intrahepatic cholangiocarcinoma (iCCA) is one of the primary liver cancers and presents with tumor heterogeneity. About 50% of iCCAs comprise actionable mutations, which completely change patient management. In addition, the precise diagnosis of iCCA, including subtype, has become crucial, and pathologists play an important role in this regard. This review focuses on iCCA heterogeneity; looking at different perspectives to guide diagnosis and optimal treatment choice.

Association of Serum Levels and Immunohistochemical Labelling of Des-Gamma-Carboxy-Prothrombin in Patients Undergoing Liver Transplantation for Hepatocellular Carcinoma.

Hepatocellular cancer (HCC) is one of the main reasons for liver transplantation (LT). Biomarkers, such as alpha-foetoprotein (AFP) and Des-gamma-carboxy-prothrombin (DCP), can be helpful in defining the recurrence risk post LT. This study aims to evaluate the association between the intensity of DCP immunohistochemical labelling and serum DCP levels in patients undergoing LT for HCC. We carried out a prospective monocentric study including patients who all underwent LT for cirrhosis between 2016 and 2018 and all fell under the Milan criteria. The accepted diagnostic criteria for HCC were contrast-enhanced imaging and histology. Thirty-nine patients were followed for a median of 21 months, with HCC lesions categorized into negative, focally positive, and diffusely positive groups based on DCP immunohistochemistry. The serum DCP levels were significantly higher in the positive groups (258 mAU/mL for the focally and 257 mAU/mL for the diffusely positive) than in the negative group (48 mAU/mL) (p = 0.005) at diagnosis and at the time of liver transplantation (220 mAU/mL for the diffuse positive group). Microvascular invasion (58.8% vs. 19.0% for the diffusely positive and negative groups, respectively, p < 0.001) and lesion size (20 mm in the diffusely labelled group versus 12 mm in the other groups, p = 0.002) were significantly correlated with DCP labelling. Late recurrence occurred only in the positive groups; in the negative group, it occurred within the first 3 months after transplantation. DCP labelling in liver lesions correlates with serum levels and a more aggressive tumour profile. Further investigation is needed to determine if highly DCP-labelled tumours allow for the better selection of high-risk patients before LT.

IgG4-related pachyleptomeningitis with inflammatory pseudotumor.

•We report the first case of IgG4-related pachyleptomeningitis.•Our case showed also an inflammatory pseudotumor on the side ipsilateral to the pachyleptomeningitis.•The pachyleptomeningitis is probably due to inflammation from the dural pseudotumor spreading along the adjacent meninges.