Papillary Thyroid Carcinoma Variants

Papillary thyroid carcinomas are the most common thyroid cancers and constitute more than 70% of thyroid malignancies. The most common etiologic factor is radiation, but genetic susceptibility and other factors also contribute to the development of papillary thyroid carcinoma. The most common variants include conventional, follicular variant and tall cell variant. However, many other uncommon variants have been described including oncocytic, columnar cell, diffuse sclerosing and solid forms. Immunohistochemical staining with TTF-1 and thyroglobulin is very useful in confirming the diagnosis of papillary thyroid carcinoma especially in metastatic sites. Markers such as HBME-1 and CITED1 can assist in separating some difficult cases of follicular variants of papillary thyroid carcinomas from follicular adenomas. Molecular studies have shown that the BRAF V600E mutation is found mainly in papillary and anaplastic thyroid carcinomas. Other molecular markers such as HMGA2 and insulin-like growth factor II mRNA binding protein 3 have been used recently as molecular tests to separate papillary thyroid carcinoma and its variants from follicular adenomas and other benign thyroid nodules

Structural, functional and molecular analysis of the effects of aging in the small intestine and colon of C57BL/6J mice

Contains fulltext : 109613.pdf (publisher's version ) (Open Access)BACKGROUND: By regulating digestion and absorption of nutrients and providing a barrier against the external environment the intestine provides a crucial contribution to the maintenance of health. To what extent aging-related changes in the intestinal system contribute to the functional decline associated with aging is still under debate. METHODS: Young (4 M) and old (21 M) male C57BL/6J mice were fed a control low-fat (10E%) or a high-fat diet (45E%) for 2 weeks. During the intervention gross energy intake and energy excretion in the feces were measured. After sacrifice the small and large intestine were isolated and the small intestine was divided in three equal parts. Swiss rolls were prepared of each of the isolated segments for histological analysis and the luminal content was isolated to examine alterations in the microflora with 16S rRNA Q-PCR. Furthermore, mucosal scrapings were isolated from each segment to determine differential gene expression by microarray analysis and global DNA methylation by pyrosequencing. RESULTS: Digestible energy intake was similar between the two age groups on both the control and the high-fat diet. Microarray analysis on RNA from intestinal scrapings showed no marked changes in expression of genes involved in metabolic processes. Decreased expression of Cubilin was observed in the intestine of 21-month-old mice, which might contribute to aging-induced vitamin B12 deficiency. Furthermore, microarray data analysis revealed enhanced expression of a large number of genes involved in immune response and inflammation in the colon, but not in the small intestine of the 21-month-old mice. Aging-induced global hypomethylation was observed in the colon and the distal part of the small intestine, but not in the first two sections of the small intestine. CONCLUSION: In 21-month old mice the most pronounced effects of aging were observed in the colon, whereas very few changes were observed in the small intestine

Malabsorption Disorders

Malabsorptive symptoms can be caused by a variety of medications and immune-mediated, infectious, and genetic disorders that share a final common pathway resulting in decreased small-intestinal surface area. Many immune-mediated and medication-related conditions cause a malabsorptive histologic pattern of injury characterized by villous blunting, intraepithelial lymphocytosis, and mononuclear cell-rich inflammation in the lamina propria. Others features include prominent epithelial cell injury, crypt cell apoptosis, and crypt destruction. Correct classification of these disorders requires knowledge of their distinctive histologic features, presenting symptoms and medical history, serologic studies, distribution of disease, and endoscopic findings. The purpose of this chapter is to address frequently asked questions that arise when evaluating biopsy or resection samples from patients with clinical features of intestinal malabsorption and offer suggestions regarding the pathologic reporting of these cases