background: reactive lesions of the oral cavity are non-neoplastic proliferations with very similar clinical appearance to benign neoplastic proliferation. this similarity is troublesome in the differential diagnosis. the aim of this study was to determine the frequency and distribution of oral cavity reactive lesions. materials and methods: the study was a retrospective archive review. the med...

Although ras is a potent mitogenic oncogene, its tumorigenicity depends on cellular context and cooperative events. Here we show that low-level expression of a constitutively active Ha-ras in mouse urothelium induces simple urothelial hyperplasia that is resistant to progression to full-fledged bladder tumors even in the absence of Ink4a/Arf. In stark contrast, doubling of the gene dosage of th...

Cell type-specific conditional activation of oncogenic K-Ras is a powerful tool for investigating the cell of origin of adenocarcinomas in the mouse lung. Our previous studies showed that K-Ras activation with a CC10(Scgb1a1)-CreER driver leads to adenocarcinoma in a subset of alveolar type II cells and hyperplasia in the bronchioalveolar duct region. However, no tumors develop in the bronchiol...

The increasing frequency and poor prognosis in pancreatic cancer prompt us to search for morphological lesions being a substrate for its development. Studies of autopsy and surgically resected material as well as recent molecular studies have proved that one of the possible pathways of pancreatic neoplasia is the intraepithelial proliferation--dysplasia--cancer sequence. In the present paper we...

Virtually all germline RET pathogenic variant carriers develop medullary thyroid carcinoma (MTC). If possible, thyroidectomy should be performed prophylactically, before developing MTC. We describe a patient with pheochromocytoma found to have p.Cys634Ser at age sixty years who would categorized as high risk based on genotype classification described by the American Thyroid Association and warr...

Solitary angiokeratoma of oral mucosa is rare entity. The term Angiokeratoma is used to refer to several lesions, whose common denominator is the presence of dilated blood vessels in association with epidermal hyperplasia. Mucosal involvement, including oral cavity is occasionally found either as a component of the systemic variety, cutaneous involvement or isolated oral involvement. Clinically...

The traditional approach to oncocytic thyroid lesions classified these as a separate entity, and applied criteria that are somewhat similar to those used for follicular lesions of the thyroid. In general, the guidelines to distinguish hyperplasia from neoplasia, and benign from malignant were crude and unsubstantiated by scientific evidence. In fact, there is no basis to separate oncocytic lesi...

congenital and acquired abnormalities of the reproductive tract of female sheep resulting in subfertility,infertility or sterility cannot easily be detected by routine clinical examination. morphopathologicalabnormalities of the reproductive tract of ewes were studied by examining a total of 739 genital tracts inabattoirs of fars province, iran. from these, the 648 non-pregnant genitalia were e...

Promoter hypermethylation of tumor suppressor genes has been confirmed to serve a pivotal role in tumorigenesis. Protocadherin 8 (PCDH8), a novel tumor suppressor gene, has been reported to be inactivated by promoter hypermethylation a number of cancer types, including bladder cancer and renal cell carcinoma. The aim of the present study was to investigate the occurrence of PCDH8 hypermethylati...

Intravascular papillary endothelial hyperplasia (intravascular angiomatosis) is a lesion which several authors regard as a reactive phenomenon associated with such vascular alterations as hemangiomas, hematomas, varix, thrombi or dilated vessels while others consider it a neoplasm. An extensive review of the literature and a discussion of the previously reported points of view with a report of ...