Rokitansky-Aschoff Sinuses Mimicking Adenocarcinoma of the Gallbladder: A Study of 8 Cases

Xanthogranulomatous cholecystitis: diagnostic complexity and review of the literature

We report the case of a 39-year-old male presenting with acute onset vomiting and diarrhoea. Initially treated empirically for gastroenteritis, imaging later confirmed a complicated episode of cholecystitis with fistular formation and intra-abdominal cyst. Following cholecystectomy, histology confirmed a case of xanthogranulomatous cholecystitis (XGC). This paper presents a detailed summary of the condition alongside a literature review of all available episodes of XGC since 2017 with the aim of highlighting diagnostic conclusions regarding the nature of the disease and its clinical manifestations.

Gallbladder carcinomas: review and updates on morphology, immunohistochemistry, and staging

Gallbladder is a common surgical pathology specimen. However, carcinomas of the gallbladder are relatively rare in most western countries. Hence, general surgical pathologists may not be that familiar and comfortable diagnosing these tumors. In this review, we discuss the morphological and immunohistochemical characteristics of gallbladder carcinomas, provide updates on tumor classification and staging of these tumors as per the most recent WHO classification, and focus on practical considerations that would be most relevant to diagnosis and clinical management of these tumors.

Intraepithelial involvement of non-neoplastic glands in papillary preinvasive neoplasms of the biliary tract: a potential diagnostic pitfall

Intracholecystic papillary neoplasms of the gallbladder (ICPN) and intraductal papillary neoplasms of the bile duct (IPNB) show intramural neoplastic growths in addition to intraluminal papillary or polypoid neoplastic growth. Such intramural growths include intraepithelial involvement of non-neoplastic glands by preinvasive neoplastic epithelia (glandular involvement) as well as stromal invasive carcinoma. A total of 29 ICPN cases and 84 IPNB cases were pathologically examined for their glandular involvement. Glandular involvement was characterized by intramural neoplastic glands (1) showing cytological and phenotypical similarities to intraluminal preinvasive papillary neoplasms and (2) showing reminiscent configurations of non-neoplastic glands, such as (i) a mixture of preinvasive neoplastic epithelia and non-neoplastic epithelia within the same glands, (ii) neoplastic glands close to or within clustered non-neoplastic glands, or (iii) continuous growth of intraluminal preinvasive neoplastic glands into the walls. Such glandular involvement was found in 16 of 29 ICPN and 48 of 84 IPNB, and 15 of the former and 28 of the latter were not associated with invasive carcinoma. Non-invasive ICPN and IPNB with glandular involvement showed a favorable postoperative overall survival (OS). Glandular involvement by preinvasive neoplastic epithelia was frequently found in ICPN and IPNB. Such lesions may be diagnostic pitfalls in ICPN and IPNB referring to invasion. Glandular involvement without invasive carcinoma was not associated with an unfavorable postoperative OS in ICPN and IPNB. Recognition of glandular involvement may thus prevent overestimation of invasive carcinoma in ICPN and IPNB.

Epigenetic Inheritance From Normal Origin Cells Can Determine the Aggressive Biology of Tumor-Initiating Cells and Tumor Heterogeneity

The acquisition of genetic- and epigenetic-abnormalities during transformation has been recognized as the two fundamental factors that lead to tumorigenesis and determine the aggressive biology of tumor cells. However, there is a regularity that tumors derived from less-differentiated normal origin cells (NOCs) usually have a higher risk of vascular involvement, lymphatic and distant metastasis, which can be observed in both lymphohematopoietic malignancies and somatic cancers. Obviously, the hypothesis of genetic- and epigenetic-abnormalities is not sufficient to explain how the linear relationship between the cellular origin and the biological behavior of tumors is formed, because the cell origin of tumor is an independent factor related to tumor biology. In a given system, tumors can originate from multiple cell types, and tumor-initiating cells (TICs) can be mapped to different differentiation hierarchies of normal stem cells, suggesting that the heterogeneity of the origin of TICs is not completely chaotic. TIC’s epigenome includes not only genetic- and epigenetic-abnormalities, but also established epigenetic status of genes inherited from NOCs. In reviewing previous studies, we found much evidence supporting that the status of many tumor-related “epigenetic abnormalities” in TICs is consistent with that of the corresponding NOC of the same differentiation hierarchy, suggesting that they may not be true epigenetic abnormalities. So, we speculate that the established statuses of genes that control NOC’s migration, adhesion and colonization capabilities, cell-cycle quiescence, expression of drug transporters, induction of mesenchymal formation, overexpression of telomerase, and preference for glycolysis can be inherited to TICs through epigenetic memory and be manifested as their aggressive biology. TICs of different origins can maintain different degrees of innate stemness from NOC, which may explain why malignancies with stem cell phenotypes are usually more aggressive.

Reduced MFAP5 expression in stroma of gallbladder adenocarcinoma and its potential diagnostic utility

The diagnosis of invasive adenocarcinoma of the gallbladder can sometimes be challenging. The presence of true desmoplastic reaction facilitates the diagnosis of invasion. However, desmoplasia-like changes can be observed in benign gallbladder conditions, and recognition of desmoplasia may be challenging based on morphology. In this study, we tested the expression pattern of microfibril-associated protein 5 (MFAP5), a promising immunohistochemical marker for desmoplasia, in benign gallbladders with desmoplasia-like reaction and gallbladders with invasive adenocarcinoma. We also evaluated the diagnostic utility of MFAP5 in challenging cases with an interobserver agreement study. The results showed that all benign cases retained intact/positive MFAP5 staining pattern in periglandular connective tissue, whereas 79.3% (23 out of 29) of cases of adenocarcinomas demonstrated diffuse and complete loss of MFAP5 staining in the tumor stroma. Interobserver agreement was improved by 2.66 times when images of MFAP5 immunohistochemistry were provided. In conclusion, MFAP5 expression is downregulated in the desmoplastic stroma of gallbladder adenocarcinoma and may provide a useful diagnostic marker in difficult cases.