Human pathology
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SALL4 is a transcription factor that serves as a marker of yolk sac tumor. Yolk sac tumor and hepatocellular carcinoma share histologic, serologic, and immunohistochemical features. Previous studies have shown lack of SALL4 expression in hepatocellular carcinoma, suggesting utility in this differential diagnosis. ⋯ This is the first report of SALL4 expression in hepatocellular carcinoma. Our finding should be taken into consideration in the differential diagnosis of hepatocellular carcinoma and yolk sac tumor. The unique punctuate/clumped pattern seen in hepatocellular carcinoma cases could be of further discriminatory value.
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Sex-determining region Y-box 2 gene at 3q26.33 has been identified as oncogene in squamous cell carcinoma occurring at different anatomical sites including the lung. Sex-determining region Y-box 2 protein expression and gene amplification have been found in preinvasive squamous cell lesions such as dysplasia and carcinoma in situ. We sought to evaluate sex-determining region Y-box 2 expression and amplification in a spectrum of premalignant squamous lesions ranging from squamous metaplasia to low- and high-grade dysplasia to in situ and invasive squamous cell carcinoma of the lung. ⋯ Sex-determining region Y-box 2 protein expression was seen in all squamous lesions regardless of presence or degree of dysplasia. Our results suggest that sex-determining region Y-box 2 amplification is not an early event in squamous carcinogenesis and is important for progression in a subset of squamous cell carcinoma. It appears that sex-determining region Y-box 2 gene amplification in lung squamous carcinogenesis is not the only regulator of sex-determining region Y-box 2 protein expression.
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Kikuchi-Fujimoto lymphadenitis is a self-limited disorder that typically presents in young females as painless cervical lymphadenopathy with fever, anemia, and leukopenia. The clinical manifestations and pathologic findings suggest a viral etiology, yet specific etiologic agents remain unknown. Although there are studies reporting positive associations between Kikuchi-Fujimoto lymphadenitis and parvovirus B19 and herpesviruses, other studies have failed to find an association with these viruses. ⋯ There were no significant differences between cases and controls in the prevalence of Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8 (P = .50 for all 3). Polymerase chain reaction failed to reveal a positive association between Kikuchi-Fujimoto lymphadenitis and 4 common suspected viral agents. These findings do not support a role for Epstein-Barr virus, human herpesvirus 6, human herpesvirus 8, or parvovirus B19 in the pathogenesis of Kikuchi-Fujimoto lymphadenitis.
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Comparative Study
Immunohistochemical characteristics and malignant progression of hepatic cystic neoplasms in comparison with pancreatic counterparts.
The recent World Health Organization classification for tumors of the digestive system defined grossly and histologically hepatic mucinous cystic neoplasms and intraductal papillary neoplasms of the bile duct separately. In this study, the immunohistochemical features of intraductal papillary neoplasm of the bile duct (19 cases) and hepatic mucinous cystic neoplasm (5 cases) were characterized and compared with those of similar pancreatic lesions, intraductal papillary mucinous neoplasm of the pancreas (12 cases), and pancreatic mucinous cystic neoplasm (6 cases) and with those of other biliary cystic lesions, peribiliary cysts (10 cases). Intraductal papillary neoplasm of the bile duct and intraductal papillary mucinous neoplasm of the pancreas frequently expressed cytokeratin 7; mucin core proteins 1, 2, 5AC, and 6; trypsin; and amylase. ⋯ The p16 labeling index decreased and EZH2 labeling index increased significantly with the malignant progression of intraductal papillary neoplasm of the bile duct and intraductal papillary mucinous neoplasm of the pancreas. In conclusion, intraductal papillary neoplasm of the bile duct and hepatic mucinous cystic neoplasm might be regarded as biliary counterparts of intraductal papillary mucinous neoplasm of the pancreas and pancreatic mucinous cystic neoplasm, respectively, and the mucinous cystic neoplasm and intraductal papillary neoplasm groups differed from each other. Labeling indexes of Ki-67, p53, p16, and EZH2 were comparable in intraductal papillary neoplasm of the bile duct and intraductal papillary mucinous neoplasm of the pancreas along with their malignant progression, suggesting a common carcinogenic process of the tumors.
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Circulating memory B cells are considered as the main reservoir for Epstein-Barr virus. Several studies identified the presence of Epstein-Barr virus-infected B cells in the lesions of Crohn disease and ulcerative colitis suggesting that colon mucosa with chronic inflammation could be a potential site of Epstein-Barr virus replication. However, whether skin could be also an Epstein-Barr virus reservoir has not yet been investigated. ⋯ Altogether, these data suggest that, in immunocompetent patients, skin inflammatory lesions contain Epstein-Barr virus-infected cells exhibiting latency type I. Moreover, skin-like gastrointestinal mucosa is a potential site of Epstein-Barr virus replication and spreading. Our results may explain the pathogenesis of the Epstein-Barr virus-positive mucocutaneous ulcer.