Adenoma follicular

Eight rats had at least one of the tumors tabulated here. In addition, the following miscellaneous tumors were noted 1 rat had cortical adenoma of adrenal gland, 1 had follicular adenoma of thyroid gland, and 1 had pulmonary adenoma. 

Follicular adenomas and follicular carcinomas are usually indistinguishable in radiological, cytopathological or clinical features, unless, of course, metastases are present. The distinction relies on detection of capsular or vascular invasion at the periphery of the carcinoma, and this, in turn, requires surgical excision—an expensive and not risk-free operation—and detailed pathological examination of the specimen. 

One-dimensional MR spectra (Fig. 2) for 107 thyroid biopsies were analysed in this study, including 11 normal (N), 13 papillary carcinomas (PC), 4 other carcinomas (anaplastic, medullary), and 73 follicular adenomas, of which 10 were clinically manifest as follicular carcinoma (FC).46... 

Follicular adenomas are positive for TGB but also show considerable variability in staining intensity on the basis of the functional status of their component cells.As would be expected, hyperfunctional adenomas exhibit strong positivity for TGB, whereas the cells of macrofollicular adenomas have considerably less reactivity and may be negative. Normofollicular adenomas demonstrate moderate immunoreactivity for TGB, whereas adenomas of solid and oncocytic types contain smaller amounts of TGB in the component cells. 

Numerous other proteins have been explored as potential markers for different types of thyroid malignancies (Table 10.3). Cbp/p300-interacting transactivator 1 (CITEDl) is a nuclear protein that is involved in the coregulation of transcription factors. This protein is present in a variety of different cell types and is overexpressed in papillary thyroid carcinomas (87% to 93%). However, CITEDl immunoreactivity is also expressed in up to 50% of follicular carcinomas, 16% of follicular adenomas, and 24% of nodular goiters. 

S-100 protein has also been studied in neoplastic lesions of the thyroid gland. McLaren and Cossar reported positivity in 100% of papillary carcinomas, 75% of follicular carcinomas, 37.5% of follicular adenomas, and 28.5% of papillary hyperplasias. ... 

RAS mutations are present in approximately 50% of follicular carcinomas and 20% to 40% of follicular adenomas (Table 10.4)2 1 Among RAS-positive carcinomas, N-RAS codon 61 mutations are present in approximately 80% of cases and H-RAS codon 61 mutations are present in almost 20%. Identical mutations are present at lower frequencies in follicular adenomas. RAS mutations also occur in approximately 25% of oncocytic carcinomas and in up to 5% of oncocytic adenomas. 

RAS mutations are present in approximately 50% of follicular carcinomas and in 20% to 40% of follicular adenomas. 

PAX-8-PPARy rearrangements occur in approximately 35% of follicular carcinomas and in 10% of follicular adenomas. 

Mixed medullary and follicular cell carcinoma Spindle cell tumor with thymus-like differentiation Carcinoma showing thymus-like differentiation Thyroid adenoma and related tumors Follicular adenoma Hyalinizing trabecular tumor... 

Familial papillary carcinoma Familial oxyphil cell carcinoma Werner syndrome Carney complex Familial MTC, MEN2A, MEN2B Precursor follicular cell tumor Follicular adenoma Papillary or follicular carcinoma Hypercalcaemia Thyroiditis... 

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