PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “thyroid nodules”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1977

[Scintigraphic discordances between technetium 99m and iodine 131 in the study of thyroid nodules].

Eighty thyroid nodules found to be hyperfixating, isofixating or heterogeneous after an initial scintigraphy with Technetium 99m were studied comparatively using iodine 131. Differences in the apparent activity of the nodule and the extra-nodular parenchyma were found in one third of cases. A "cold nodule" appearance, not seen with techneitum was found in 8 cases at the time of the examination using iodine. Five of these patients underwent operation, the diagnosis being a carcinoma in one.

Adenocarcinoma↗
PubMed1997

Effectiveness of the thyroid scan in evaluation of the solitary thyroid nodule.

Solitary, palpable thyroid nodules are common, but only a small percentage are malignant. It is important to evaluate these nodules in a cost-efficient manner that avoids missing a cancer. Historically, radioisotope imaging has played a major role in the workup of thyroid nodules; however, with the advent of fine needle aspiration biopsy (FNAB), this role has become less clear. From 1974 to 1994, 770 patients with a solitary nodule underwent thyroidectomy. Preoperatively, 471 had thyroid scans, and 149 had FNAB. The incidence of carcinoma in nodules excised on the basis of thyroid scan was 23 per cent, whereas the incidence of carcinoma was 37 per cent when FNAB was used (P = 0.003). Fine needle aspiration was a significantly better predictor of malignancy than thyroid scan and resulted in a smaller proportion of excisions for benign nodules. Thyroid scan provided little additional information in those patients who underwent FNAB. Because thyroid scans add little in determining which nodules require surgical excision, they should no longer be a routine part of the evaluation of a solitary thyroid nodule.

Adolescent↗
PubMed1979

[Thyroid nodule secondary to subacute thyroiditis. 8 cases (author's transl)].

This description of 8 cases of thyroid nodules secondary to subacute thyroiditis serves to emphasise the relative prevalence of the circumscribed forms. These nodules, variable in size, firm and painful, developed after a period of cervical discomfort and pain. A contrast between a raised or normal blood hormone level and a very low uptake of I131 was found in five cases. It was all the more valuable when there was no iodine overload. Scintigraphy showed the nodule to be cold in 6 cases, isofixing in one and hot in one case. An essential diagnostic criterion is the rapidly favourable course: 4 nodules disappeared completely, 3 regressed in less than 6 months and one persisted, justifying excision with histopathological examination since localised thyroiditis of this type may be the presenting feature of a carcinoma.

Adult↗
PubMed2003

Fine-needle aspiration cytology of thyroid nodules: how useful is it?

BACKGROUND: Thyroid nodules are common and the principal method of diagnosis is fine-needle aspiration cytology (FNAC). METHODS: To determine the value of FNAC in the diagnosis of thyroid nodules, thyroid cytology of 253 patients with definitive histology after surgery was analyzed from 1992 to 2002. FNAC was correlated with histology and the sensitivity, specificity and likelihood ratios were calculated. The method of FNAC and number of non-diagnostic aspirates were noted. The frequency of thyroid cancer was investigated in male and females who presented with a solitary thyroid nodule. RESULTS: The overall sensitivity of FNAC detecting thyroid neoplasia was 55.0%, specificity 73.7% and accuracy 67.2%. Likelihood ratios indicate that a 'malignant' or 'suspicious for malignancy' cytology dramatically increase the pretest probability of thyroid neoplasia. There were no false positive 'malignant' FNAC. Ultrasound guided FNAC had a significantly lower non-diagnostic rate compared to freehand FNAC (P < 0.02). Of 22 males, 22.7% who proceeded to surgery for their solitary nodule had thyroid carcinoma compared with 11.9% of 167 females (P = 0.02). CONCLUSIONS: FNAC was essential to management in this series of patients. 'Malignant' or 'suspicious for malignancy' cytology are absolute indicators for thyroidectomy. FNAC should be undertaken with ultrasound guidance and if possible with a pathologist in attendance to assess sample adequacy. We recommend a high index of suspicion of thyroid cancer in the male patient who presents with a solitary nodule. If solitary nodules are to be observed, repeat FNAC should be undertaken because of the high false negative rate.

Biopsy, Fine-Needle↗
PubMed2001

Pathogenesis of thyroid nodules: histological classification?

Thyroid nodule genesis may be considered as an amplification of thyroid heterogeneity due to genetic and/or epigenetic mechanisms. We classified the thyroid nodules in five types with distinct histological features: hyperplastic, neoplastic, colloid, cystic and thyroiditic nodules. Hyperplastic: Thyrocyte proliferation is under the control of TSH but several other paracrine and autocrine factors are secreted by follicular cells, the stromal apparatus and the lymphocytes, which are implicated in initiation and perpetuation of thyroid hyperplasia. Growth occurs mainly through TSHR, cAMP and PKA. Constitutive cAMP overproduction has been shown to be due to point mutation of the TSHR or Gs protein, producing overgrowth and hyperfunction. Neoplastic: Several activated oncogenes have been identified in thyroid malignancies. Oncogenes relevant to the thyroid carcinogenesis are: mutated TSHR and gsp (constitutive activation of cAMP); TRK (receptor for NGF); RET/PTC (phosphorylation of tyrosine kinase receptor)--an isoform of this oncogene is induced by radiation: ras (it encodes Gs proteins transducing mitogenic signals); and c-MET (receptor for hepatocyte growth factor). The evolution of a differentiated thyroid cancer towards an undifferentiated cancer is due to a mutation of a family of proteins (i.e., p53), which acts as a brake, preventing the genomic instability of cancer. It is suggested that a tumor initiates by RET or ras and possibly progresses--as a result of additional mutations and by p53 mutation--to anaplastic carcinoma. Colloid: Flattening of the epithelium and dilatation of follicles containing viscous material--made up by a concentrated solution of thyroglobulin (hTg)--is the characteristic of the colloid nodule. A defect of intraluminal reabsorption of hTg has been suggested but not proven. Experimentally, a load of iodine is able to change thyroid hyperplasia to a colloid feature; however, a load of iodine is rarely found in the clinical history of patients. A new clue to the pathogenesis comes from the finding that a relevant part of the colloid (10-20%) is made up of insoluble globules, where hTg is compacted in a polymeric form. It is suggested that stocking hTg into globules is defective in colloid nodules, leading to enormous enlargement of the follicle. Cystic: It is estimated that between 15 and 40% of thyroid nodules are partly or entirely cystic. The 'true cyst' is rare; most of the so-called cystic nodules are 'pseudocysts', which follow necrosis and colliquation. Necrosis issues as an imbalance between growth and the precisely regulated process of angiogenesis. More recently, the VEGF/VPF has been found to be at the origin of recent and recurrent cysts. Immunotoxic and apoptotic mechanisms have also been suggested. Chemical analysis of cystic fluid showed a 'denatured' and 'serum-like' pattern suggesting different mechanisms in the pathogenesis of the pseudocystic thyroid nodules. Thyroiditic: Nodular lymphocytic thyroiditis (NLT) includes two different entities: 1) lymphocyte thyroiditis growing as a nodule in a hyperplastic or normal gland, and 2) lymphocyte thyroiditis associated in the same nodule with other nodular diseases of the thyroid: papillary thyroid carcinoma and lymphoma have been found to be associated to chronic lymphocytic thyroiditis.

Humans↗
PubMed1993

[The thyroid nodule. Diagnostic considerations].

Thyroid nodule is extremely common. Its prevalence has been estimated to be more than 5% in the adult population. If thyroid nodule is a rare condition, 0.004% a year, identifying those nodules, which are likely to be malignant, is very important for physicians. The evaluation of thyroid is carried out using the fine needle aspiration biopsy (FNAB), the ultrasonography, and scanning with 131I and 99Tc. Before FNAB thyroid scans was the most common test in clinical evaluation of thyroid nodules, used to identify "hot" and "cold" lesions. Hot or warm nodules, about 5%, are seldom malignant, whereas cold or hypofunctional have a 10% to 25% chances of being malignant. FNAB is the elected laboratory test: this procedure is easily, simple, non traumatic, and very acceptable to the patients. Ultrasound is useful in several settings: it provides a non invasive and relatively inexpensive means of following the size of nodule, after medical therapy and FNAB.

Adult↗
PubMed1996

Treatment guidelines for patients with thyroid nodules and well-differentiated thyroid cancer. American Thyroid Association.

A set of minimum clinical guidelines for use by primary care physicians in the evaluation and management of patients with thyroid nodules or thyroid cancer was developed by consensus by an 11-member Standards of Care Committee (the authors of the article) of the American Thyroid Association, New York, NY. The participants were selected by the committee chairman and by the president of the American Thyroid Association based on their clinical experience. The committee members represented different geographic areas within the United States, to reflect different practice patterns. The guidelines were developed based on the expert opinion of the committee participants, as well as on previously published information. Each committee participant was initially assigned to write a section of the document and to submit it to the committee chairman, who revised and assembled the sections into a complete draft document, which was then circulated among all committee members for further revision. Several of the committee members further revised and refined the document, which was then submitted to the entire membership of the American Thyroid Association for written comments and suggestions, many of which were incorporated into a final draft document, which was reviewed and approved by the Executive Council of the American Thyroid Association.

Adenocarcinoma, Follicular↗
PubMed2000

The changing role of scintigraphy in the evaluation of thyroid nodules.

Nodular thyroid disease is common. Most nodules are asymptomatic and benign, but some are malignant. Fine needle aspiration (FNA) biopsy should be the cornerstone of the evaluation of thyroid nodules. Radionuclide scans and other imaging procedures should be considered adjunctive tests and should not be performed until after determination of thyroid function and results of cytology are available.

Algorithms↗
PubMed1999

Spuriously elevated plasma calcitonin in a patient with a thyroid nodule not associated with medullary thyroid carcinoma.

An increase in plasma calcitonin concentration is widely regarded as a specific and sensitive indication of underlying medullary thyroid carcinoma (MTC). We present a case in which the association of increased plasma calcitonin concentration and a thyroid nodule was not due to MTC. Subsequent measurement of plasma calcitonin by a variety of methods highlighted the variability that exists in calcitonin measurement and the potential for clinically misleading results. The rationale for investigation and treatment of MTC, including a recommendation to screen all patients with thyroid nodules using plasma calcitonin measurement, is based on the use of specific two-site calcitonin assays which are not universally used in the UK or USA.

Biomarkers↗
PubMed1998

T3-release from autonomously functioning thyroid nodules in vitro.

Toxic thyroid nodules have been shown to be of clonal origin. In a portion of them, point mutations affecting either the gene of the TSH receptor (TSHr) or the alpha-subunit of stimulating G-protein, consecutively leading to enhanced cAMP levels, which may enhance growth or functional activity of the thyrocyte or both, were recently found. To complement these studies, we evaluated hormone response (i.e. T3 release) in vitro from tissues derived from toxic thyroid nodules as compared directly to the surrounding paranodular tissues as well as tissues derived from euthyroid goiter and from patients with Graves' disease. Experiments were conducted in the presence and absence of bTSH or Graves' immunoglobulines. Tissues obtained during surgery were incubated over 5 h, followed by equilibrium dialysis for 24 h, and determination of free T3 in an aliquot by RIA. Basal T3 release in nodular tissues (n = 10) was significantly higher (median: 7.3 ng/l) compared to paranodular tissues (3.2 ng/l; P < 0.01), tissues derived from euthyroid goiter (1.3 ng/l; n = 12; P < 0.001) and thyroid tissues derived from patients with Graves' disease (2.5 ng/l; n = 6; P < 0.001). Upon stimulation with bTSH (1 IU/l), median T3 concentrations markedly increased to 11.5 ng/l (P < 0.05), 7.3 ng/l (P < 0.05), 4.2 ng/l (P < 0.01) and 3.2 ng/l (P = N.S.), respectively. Stimulation over basal values was 1.6-fold in nodular tissues, 2.3-fold in paranodular tissues, 3.2-fold in euthyroid goiter and 1.3-fold in Graves' disease. In toxic thyroid nodules basal hormone-releasing activities were stimulated by fifteen out of twenty (75%) Graves' sera tested. For comparison, stimulation in other tissues occurred in 45% (paranodular), 80% (euthyroid goiter) and 35% (Graves' disease), respectively. In conclusion, tissue derived from toxic thyroid nodules exhibits enhanced basal hormone release as compared to both, the surrounding paranodular tissues and tissues from euthyroid goiter in vitro, which may reflect constitutional activation of TSHr, alpha-subunit of stimulating G-protein or other so far unknown intermediate by point mutations affecting the respective genes. Hyperactivities in toxic thyroid nodules may be even further enhanced by external stimulators such as TSH or TSH receptor antibodies. The first stimulator may have clinical relevance in patients with toxic thyroid nodules and not yet suppressed TSH; the latter could play a role in the rare Marine Lenhart syndrome.

Adult↗
PubMed1972

Effects of thyroid-stimulating hormone on adenyl cyclase activity and intermediary metabolism of "cold" thyroid nodules and normal human thyroid tissue.

"Cold" thyroid nodules do not concentrate (131)I before or after thyrotropin (TSH) administration. In an attempt to elucidate the reason for this TSH unresponsiveness, the effect of TSH in vitro on several metabolic parameters was studied in 11 "cold" thyroid adenomas, 2 medullary carcinomas, and in the surrounding normal thyroid tissue. Basal adenyl cyclase activity, glucose-1-(14)C oxidation, and (32)P incorporation into phospholipids were significantly greater in the adenomas than in the adjacent normal thyroid; basal cyclic 3',5'-adenosine monophosphate (cyclic AMP) concentration and adenine-(3)H incorporation into (3)H-labeled cyclic AMP were not different. In adenomas as well as normal thyroid, all parameters responded significantly to in vitro TSH stimulation. The response to TSH of adenyl cyclase activity and (32)P incorporation was enhanced in adenomas compared with that of the adjacent normal thyroid. These differences were not explained by an increased cellularity of the adenomas. Medullary carcinomas did not respond to TSH in any of the above parameters. The studies demonstrate an intact, TSH-responsive adenyl cyclase-cyclic AMP system in the adenomas and, accordingly, imply the presence of receptor sites for TSH on the cells of the adenoma. The failure of such nodules to concentrate (131)I may be owing to a subsequent impairment in the expression of cyclic AMP action on iodine metabolism.

Adenine↗
PubMed1995

[Small thyroid nodules and microcancers].

Thyroid nodules less than one centimetre in diameter raise the problem of differential diagnosis between a benign formation and cancer. The question is of major importance since nodules can be found in approximately one-half of the population. Fine-Needle Aspiration should be performed if the nodule is palpable. When cytologic diagnosis is not possible, the discovery of a small nodule in the thyroid gland is not an alarming finding in itself as long as the absence of involvement of the satellite nodes or other associated symptomatology is confirmed. We have operated 102 patients with differentiated microcancers with no metastasis other than local node involvement. All have been seen regularly for annual check-ups and only 2 have developed pulmonary and bone metastases with a fatal outcome. The prognosis of microcancers is thus much better than that of larger tumours since in a series of more than 500 cancers we have observed 5 and 10 year survivals of 96 and 92% respectively. In addition, unlike large tumours, small cancers of the thyroid are not anaplastic. We thus propose annual surveillance for patients with uncomplicated small nodules of the thyroid gland less than 2 cm in diameter. Complementary examinations should be limited. Conversely we operate the nodules exceeding 2 cm in order to reduce the frequency and severity of thyroid cancer. It should be recalled that neither clinical manifestations, echography, thyroglobulin, needle biopsy, nor any other diagnostic tool has been shown to have sufficient prognostic power to predict the benign nature of a voluminous nodule.

Female↗