Mucinous intrahepatic cholangiocarcinoma: a distinct variant

Classification of intrahepatic cholangiocarcinoma

Cholangiocarcinoma is a heterogenous malignancy with various classifications based on location, morphological features, histological features, and actionable genetic mutations. Intrahepatic cholangiocarcinoma (ICC), which arises in and proximal to second order bile ducts, is the second most common primary liver malignancy after hepatocellular carcinoma. In this review, we will discuss ICC risk factors, precursor lesions, various growth, anatomic, morphologic, and histologic classifications, rare variants, and differential diagnoses.

Intrahepatic mucinous cholangiocarcinoma with recurrent colic in a horse case report and literature review of cholangiocarcinoma in horses

A 17-y-old Arabian mare was presented to the Auburn Large Animal Veterinary Teaching Hospital with a long-term history of intermittent mild recurrent colic that responded to medical treatment. CBC revealed mild lymphopenia; serum biochemistry findings were of increased gamma-glutamyl transferase and creatine kinase activities, hyperferremia, hyperglycemia, hypomagnesemia, and hypokalemia. Abdominocentesis was compatible with low-protein transudate. Due to the progression and duration of clinical signs, the owner elected euthanasia. Postmortem examination and histopathology confirmed a cholangiocarcinoma. The neoplastic cells were arranged in large cysts containing lakes of mucin that comprised 90% of the tumor volume; thus, a mucinous variant was determined. The neoplastic cells had strong cytoplasmic immunolabeling for cytokeratin 19 and lacked immunolabeling for hepatocyte paraffin 1, supporting bile duct origin. Cholangiocarcinomas are infrequent tumors in horses with nonspecific and slow progressive clinical signs, including recurrent colic. Mucinous cholangiocarcinomas are seldom reported in veterinary medicine and, to our knowledge, have not been reported previously in horses.

Multi-omics integrated analyzed the origin of intrahepatic mucinous cholangiocarcinoma: a case report

Intrahepatic mucinous cholangiocarcinoma (IMCC) is a rare subtype of intrahepatic cholangiocarcinoma (IHCC). Limited data describe the genetic characteristics of IMCC and insights on its pathogenesis are lacking. Here, we employed a multi-omics approach to analyze somatic mutations, transcriptome, proteome and metabolome of tumor tissue obtained from a case of IMCC in order to clarify the pathogenesis of IMCC. A total of 54 somatic mutations were detected, including a G12D mutation in KRAS that is likely to be involved in the onset of IMCC. The genes consistently up-regulated at the transcription level and in the proteome were enriched for mucin and mucopolysaccharide biosynthesis, for cell cycle functions and for inflammatory signaling pathways. The consistently down-regulated genes were enriched in bile synthesis and fatty acid metabolism pathways. Further multi-omics analysis found that mucin synthesis by MUC4 and MUC16 was elevated by up-regulated expression of mesothelin (MSLN). Moreover, transcription factor ONECUT3 was identified that possibly activates the transcription of mucin and mucopolysaccharide biosynthesis in IMCC.

MUC1 induces the accumulation of Foxp3+ Treg cells in the tumor microenvironment to promote the growth and metastasis of cholangiocarcinoma through the EGFR/PI3K/Akt signaling pathway

Tumor microenvironment (TME) plays an important role in the progression of cholangiocarcinoma. This study aims to explore whether Mucin 1 (MUC1) regulates Foxp3⁺ Treg cells in the TME of cholangiocarcinoma through the epidermal growth factor receptor (EGFR)/phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway. High-throughput sequencing dataset in the GEO database combined with GeneCards and Phenolyzer databases was used to obtain key genes in cholangiocarcinoma, followed by downstream pathway prediction. The relationship among MUC1, EGFR, and PI3K/Akt signaling pathway was explored. CD4⁺ T cells extracted from peripheral blood were induced to differentiate into Treg cells, followed by co-culture with cholangiocarcinoma cells. A mouse model was constructed to detect the role of MUC1 in the accumulation of Foxp3⁺ Treg cells, malignant phenotypes of cholangiocarcinoma, and tumorigenesis in vivo. MUC1, highly expressed in cholangiocarcinoma, might be involved in cholangiocarcinoma development. MUC1 interacted with the EGFR to activate the EGFR/PI3K/Akt signaling pathway. MUC1 overexpression could activate the EGFR/PI3K/Akt signaling pathway, which promoted the accumulation of Foxp3⁺ Treg cells in the TME and the malignant phenotypes of cholangiocarcinoma cells both in vitro and in vivo and enhanced tumorigenesis in vivo. MUC1 may interact with EGFR to activate the EGFR/PI3K/Akt signaling pathway, which induces the accumulation of Foxp3⁺ Treg cells, enhancing the malignant phenotypes of cholangiocarcinoma cells and tumorigenesis in vivo and ultimately augmenting cholangiocarcinoma growth and metastasis.

Comparison of clinicopathological characteristics of mucinous adenocarcinoma and conventional adenocarcinoma of gallbladder

BACKGROUND

Gallbladder mucinous adenocarcinoma (GBMAC) is a rare type of gallbladder malignant tumor, whereas little is known regarding the clinicopathological features and surgical outcomes of GBMAC.

METHODS

From January 2000 till December 2015, 54 GBMAC patients who underwent curative-intent surgical resection at our institution were retrospectively reviewed. We compared the clinicopathological features and surgical outcomes of these GBMAC patients with a relatively large cohort of surgically resected conventional gallbladder adenocarcinoma (GBAC) patients without existence of mucinous components.

RESULTS

The clinicopathological features of GBMAC were significantly different from conventional GBAC, including poorer tumor differentiation (P < 0.001), higher CA19-9 levels (P < 0.001), larger tumor sizes (P = 0.020), advanced AJCC tumor stage (P = 0.002), higher frequency of liver parenchyma invasion (P = 0.020), portal vein invasion (P = 0.003), lymph node metastasis (P = 0.016), lympho-vascular invasion (P < 0.001) and perineural invasion (P = 0.025). Relative to conventional GBAC patients, GBMAC patients showed significantly worse overall survival (OS) (29.0 vs 15.0 months; P < 0.001). Multivariate analysis confirmed the surgical margin (P = 0.046), tumor differentiation grade (P = 0.018), lymph node metastasis (P = 0.024), and presence of signet-ring cell component (P = 0.005) as independent prognostic factors influencing OS of patients with GBMAC.

CONCLUSION

GBMAC always had more aggressive biological behaviors and poor survival outcomes even after curative surgery. GBMAC patients with the presence of signet-ring cell component showed even worse survival outcome.

Clinical relevance of biomarkers in cholangiocarcinoma: critical revision and future directions

Cholangiocarcinoma (CCA) is a malignant tumour arising from the biliary system. In Europe, this tumour frequently presents as a sporadic cancer in patients without defined risk factors and is usually diagnosed at advanced stages with a consequent poor prognosis. Therefore, the identification of biomarkers represents an utmost need for patients with CCA. Numerous studies proposed a wide spectrum of biomarkers at tissue and molecular levels. With the present paper, a multidisciplinary group of experts within the European Network for the Study of Cholangiocarcinoma discusses the clinical role of tissue biomarkers and provides a selection based on their current relevance and potential applications in the framework of CCA. Recent advances are proposed by dividing biomarkers based on their potential role in diagnosis, prognosis and therapy response. Limitations of current biomarkers are also identified, together with specific promising areas (ie, artificial intelligence, patient-derived organoids, targeted therapy) where research should be focused to develop future biomarkers.

Genomic analysis of an aggressive case with metastatic intrahepatic mucinous cholangiocarcinoma

Intrahepatic mucinous cholangiocarcinoma (IHMC) is rare and behaves notoriously; however, the details of the clinicopathological characteristics of IHMC remain unknown. A 70-year-old man was admitted for examination of the hepatic mass in the S1 segment. He underwent extended left hepatic lobectomy. Histopathological evaluation demonstrated mixed papillary carcinoma that comprised well to moderately differentiated tubular adenocarcinoma and signet-ring cell carcinoma with large amounts of mucus lakes. Tumor was relapsed 9 months after surgery. Although he received chemotherapy with the combination of gemcitabine and cisplatin, he had renal failure and discontinued the chemotherapy. He received palliative radiotherapy for metastasis in the cervical spine. Then, the patient treated with S-1, however, he died 16 months after the initial diagnosis. The autopsy findings showed multiple nodules in the lungs, pleura, kidneys, adrenal glands, stomach, pancreas, and lymph nodes. Histological examination revealed that all nodules were IHMC. Next-generation sequencing revealed that somatic mutations in ADGRB3, TAF1L and EPHA3 may affect carcinogenesis, and those in TAF1, EPHA3, PIK3C2B, FN1, ERBB3, BRIP1, SYNE1 and TGFBR2 may affect metastasis. Molecular carcinogenesis of IHMC may be distinct from that of ordinary cholangiocarcinoma. Further studies are needed to elucidate the genetic mutations and their functions in IHMC.

Integrative Analysis of Intrahepatic Cholangiocarcinoma Subtypes for Improved Patient Stratification: Clinical, Pathological, and Radiological Considerations

Simple Summary

Liver cancer subtypes differ in prognosis and genetic alterations. An accurate diagnosis made on time is the key aspect of clinical decision-making. Hence, a correct diagnosis is of pivotal importance for individual patients. In this study, we identified the most relevant clinical, radiological, and histological parameters for an improved subtype diagnosis of intrahepatic cholangiocarcinoma. As a result of our study, the radiologist should consider factors such as growth pattern, location, and contrast agent behavior. For the pathologist, precursor lesions, mucin secretion, and a periductal-infiltrating growth are of utmost importance, while immunohistochemical analyses are essential for exclusion of extrahepatic malignancies, but have so far only value for iCCA subtype analysis in the context with other parameters.

Abstract

Intrahepatic cholangiocarcinomas (iCCAs) may be subdivided into large and small duct types that differ in etiology, molecular alterations, therapy, and prognosis. Therefore, the optimal iCCA subtyping is crucial for the best possible patient outcome. In our study, we analyzed 148 small and 84 large duct iCCAs regarding their clinical, radiological, histological, and immunohistochemical features. Only 8% of small duct iCCAs, but 27% of large duct iCCAs, presented with initial jaundice. Ductal tumor growth pattern and biliary obstruction were significant radiological findings in 33% and 48% of large duct iCCAs, respectively. Biliary epithelial neoplasia and intraductal papillary neoplasms of the bile duct were detected exclusively in large duct type iCCAs. Other distinctive histological features were mucin formation and periductal-infiltrating growth pattern. Immunohistochemical staining against CK20, CA19-9, EMA, CD56, N-cadherin, and CRP could help distinguish between the subtypes. To summarize, correct subtyping of iCCA requires an interplay of several factors. While the diagnosis of a precursor lesion, evidence of mucin, or a periductal-infiltrating growth pattern indicates the diagnosis of a large duct type, in their absence, several other criteria of diagnosis need to be combined.

Up-to-Date Pathologic Classification and Molecular Characteristics of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive primary liver malignancy with an increasing incidence worldwide. Recently, histopathologic classification of small duct type and large duct type iCCA has been introduced. Both these types of tumors exhibit differences in clinicopathological features, mutational profiles, and prognosis. Small duct type iCCA is composed of non-mucin-producing cuboidal cells, whereas large duct type iCCA is composed of mucin-producing columnar cells, reflecting different cells of origin. Large duct type iCCA shows more invasive growth and poorer prognosis than small duct type iCCA. The background liver of small duct type iCCA often shows chronic liver disease related to hepatitis B or C viral infection, or alcoholic or non-alcoholic fatty liver disease/steatohepatitis, in contrast to large duct type iCCA that is often related to hepatolithiasis and liver fluke infection. Cholangiolocarcinoma is a variant of small duct type iCCA composed of naïve-looking cuboidal cells forming cords or ductule-like structures, and shows better prognosis than the conventional small duct type. Fibrous tumor stroma, one of the characteristic features of iCCA, contains activated fibroblasts intermixed with innate and adaptive immune cells. The types of stroma (mature versus immature) are related to tumor behavior and prognosis. Low tumor-infiltrating lymphocyte density, KRAS alteration, and chromosomal instability are related to immune-suppressive tumor microenvironments with resistance to programmed death 1/ programmed death ligand 1 blockade. Data from recent large-scale exome analyses have revealed the heterogeneity in the molecular profiles of iCCA, showing that small duct type iCCA exhibit frequent BAP1, IDH1/2 hotspot mutations and FGFR2 fusion, in contrast to frequent mutations in KRAS, TP53, and SMAD4 observed in large duct type iCCA. Multi-omics analyses have proposed several molecular classifications of iCCA, including inflammation class and proliferation class. The inflammation class is enriched in inflammatory signaling pathways and expression of cytokines, while the proliferation class has activated oncogenic growth signaling pathways. Diverse pathologic features of iCCA and its associated multi-omics characteristics are currently under active investigation, thereby providing insights into precision therapeutics for patients with iCCA. This review provides the latest knowledge on the histopathologic classification of iCCA and its associated molecular features, ranging from tumor microenvironment to genomic and transcriptomic research.

Metastatic Cancer of Apparent Colon Origin With No Intraluminal Cancer After Resection of Colorectal Lateral Spreading Lesions

We report a case of metastatic adenocarcinoma to the liver that presented 5 months after piecemeal endoscopic mucosal resection of 3 benign lateral spreading adenomas in the cecum. The pathologic features of the metastatic cancer indicated a probable colonic origin. However, when the cancer was identified, there was no endoscopic evidence of recurrent polyp or another primary lesion in the colon.

Pathological aspects of mucinous cholangiocarcinoma: A single-center experience and systematic review

Cholangiocarcinoma is a malignant neoplasm originating from the biliary epithelium. Its incidence is highest in Southeast Asia, especially in Thailand. Mucinous intrahepatic cholangiocarcinoma (mucinous iCCA), characterized by an abundant extracellular mucin pool accounting for at least 50% of total tumor volume, is an extremely rare variant of such malignancy and is notorious for rapid progression and dismal prognosis. We conducted an 11-year retrospective analysis of resected mucinous iCCAs from our institution with a systematic review on mucinous iCCAs and combined hepatocellular-mucinous cholangiocarcinoma (cHCC-mCCA). There were four resected mucinous iCCA specimens at our institution (prevalence = 0.5%). Most of the patients were male. The clinicopathological characteristics were variable. The diagnosis of mucinous iCCAs could not be rendered without pathological evaluation. Either intraductal papillary neoplasm or biliary intraepithelial neoplasia was present in three out of four cases. One patient passed away at 11 months following liver resection. A total of 19 mucinous iCCAs and four cHCC-mCCAs from previously published literature were analyzed. The 1-year mortality rate of mucinous iCCAs from our series and published literature is 35%. The present study confirmed that mucinous iCCA is an exceedingly uncommon variant of iCCA. The differential diagnoses include metastatic carcinoma with mucinous component and cHCC-mCCA.

Prognostic significance of mucinous component in hilar cholangiocarcinoma after curative-intent resection

BACKGROUND

The presence of mucinous component has been indicated to have a prognostic value in adenocarcinoma. However, little is known regarding the clinicopathological characteristics and prognosis of hilar cholangiocarcinoma (HC) with mucinous component (HCM).

METHODS

Between January 1996 and December 2014, a total of 61 HCM patients who underwent curative-intent resection at West China Hospital were retrospectively reviewed. The clinicopathological characteristics and survival of these patients were compared with a large cohort of 217 surgically resected conventional HC patients during the same period.

RESULTS

The clinicopathological characteristics of HCM were distinct from conventional HC, including higher CA19-9 levels, larger tumor sizes, less differentiation, and a high frequency of liver parenchyma invasion, portal vein invasion, and lymphovascular invasion. HCM patients showed significantly worse recurrence-free survival (13.4 vs 23.9 months; P = .011) and overall survival (18.2 vs 32.1 months; P = .019) compared with conventional HC patients. Multivariate analysis confirmed liver parenchyma invasion, N stage, surgical margin, and histological grade as independent prognostic factors influencing overall survival in HCM patients.

CONCLUSION

HCM showed distinct clinicopathological features, more aggressive biological behaviors, and poor prognosis in comparison with conventional HC. Therefore, the mucinous component is an adverse prognostic factor for HC.

Pattern of distant metastases in primary extrahepatic bile-duct cancer: A SEER-based study

Extrahepatic bile duct cancer (EBDC) is a combined type of malignancy mainly consisting of extrahepatic cholangiocarcinoma and gallbladder cancer. Clinically, it is featured with latent symptoms and early metastasis, leading to a poor prognosis. Therefore, this cohort study aimed to depict the possible metastatic patterns of EBDC of diverse sub-types and evaluate the prognostic significance of diverse metastatic destinations with data from the clinical database. Relevant data of total 4061 confirmed EBDC patients diagnosed between 2010 and 2013 from the Surveillance, Epidemiology and End Results (SEER) database was obtained. We applied t test to describe the baseline data of patients included and used chi-square test to compare the distribution of distant metastatic sites. We further adopted odds ratio assess the combined metastatic patterns and compared survival difference of patients with different distal metastasis organ by Kaplan-Meier analysis. We identified totally 4061 patients over 18 years old diagnosed with extrahepatic bile tract malignancies between 2010 and 2013, with clear metastatic status and follow-up data, without primary malignancies. Liver and distant lymph (DL) are the two most common sites as a single metastasis organ. In combined metastasis patterns, bi-organ is more frequent than the other types. Lung is the organ preferentially for bi-organ metastasis, while bone and distant lymph similarly intend to co-metastasize with brain. Distal metastasis in EBDC patients indicates an extremely poor prognosis. According to the final analysis results, malignancies in extrahepatic bile duct exhibit similar metastatic patterns, suggesting that we can regard them as a unity to assess its development. Profound differences exist in distribution of distant extrahepatic metastatic sites and their combinations. Results from our studies would provide some information for follow-up strategies and future studies.