Thyroid Carcinoma Presenting as a hot Nodule

Clinical characteristics associated with the finding of thyroid cancer originating from hot nodules in patients with hyperthyroidism: a case report and systematic review of the literature

Coexistence between thyroid cancer and hyperthyroidism is rare, and most of the nodular lesions from which a malignant tumor is documented in this group of patients correspond to cold nodules. Justified by the increasing number of reports in the literature about malignant tumors diagnosed from hot nodules, a systematic review was carried out to determine possible factors associated with the diagnosis of thyroid cancer from hot nodules in patients with hyperthyroidism. The results suggest that the clinical diagnosis of toxic nodular goiter, nodular lesions of diameter > 10 mm and a histological type compatible with a follicular carcinoma, are factors that on their own increase the risk of making the diagnosis of cancer from a hot nodule.

Malignancy risk of hyperfunctioning thyroid nodules compared with non-toxic nodules: systematic review and a meta-analysis

Background

Hyperfunctioning or hot nodules are thought to be rarely malignant. As such, current guidelines recommend that hot nodules be excluded from further malignancy risk stratification. The objective of this systematic review and meta-analysis is to compare the malignancy risk in hot nodules and non-toxic nodules in observational studies.

Methods

Ovid MEDLINE Daily and Ovid MEDLINE, EMBASE, Scopus, and Web of Science databases were searched. Observational studies which met all of the following were included: (1) use thyroid scintigraphy for nodule assessment, (2) inclusion of both hyperfunctioning and non-functioning nodules based on scintigraphy, (3) available postoperative histopathologic nodule results, (4) published up to November 12, 2020 in either English or French. The following data was extracted: malignancy outcomes include malignancy rate, mapping of the carcinoma within the hot nodule, inclusion of microcarcinomas, and presence of gene mutations.

Results

Among the seven included studies, overall incidence of malignancy in all hot thyroid nodules ranged from 5 to 100% in comparison with non-toxic nodules, 3.8–46%. Odds of malignancy were also compared between hot and non-toxic thyroid nodules, separated into solitary nodules, multiple nodules and combination of the two. Pooled odds ratio (OR) of solitary thyroid nodules revealed a single hot nodule OR of 0.38 (95% confidence interval (CI) 0.25, 0.59), toxic multinodular goiter OR of 0.51 (95% CI 0.34, 0.75), and a combined hot nodule OR of 0.45 (95% CI 0.31, 0.65). The odds of malignancy are reduced by 55% in hot nodules; however, the incidence was not zero.

Conclusions

Odds of malignancy of hot nodules is reduced compared with non-toxic nodules; however, the incidence of malignancy reported in hot nodules was higher than expected. These findings highlight the need for further studies into the malignancy risk of hot nodules.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13044-021-00094-1.

Hyperfunctioning thyroid carcinoma: A systematic review

Hyperthyroidism may be caused by the development of primary or metastatic thyroid carcinoma. The aim of the present study was to collect recently reported cases of hyperfunctioning thyroid carcinoma in order to analyze its pathological characteristics, diagnostic procedures and treatment strategies. A PubMed (https://www.ncbi.nlm.nih.gov/pubmed/) search was performed for studies published between January 1990 and July 2017. Full-text articles were identified using the terms, ‘hyperfunctioning thyroid carcinoma/cancer’, ‘malignant hot/toxic thyroid nodule’, or ‘hyperfunctioning papillary/follicular/Hürthle thyroid carcinoma’. Original research papers, case reports and review articles were included. Among all thyroid carcinoma cases included in the present study, the prevalence of follicular thyroid carcinoma (FTC) was ~10%; however, the prevalence of FTC among hyperfunctioning thyroid carcinomas was markedly higher (46.5% in primary and 71.4% in metastatic disease). The size of hyperfunctioning thyroid tumors was considerably larger compared with that of non-hyperfunctioning thyroid tumors, with a mean size of 4.25±2.12 cm in primary hyperfunctioning thyroid carcinomas. In addition, in cases of metastatic hyperfunctioning thyroid carcinoma, tumor metastases were widespread or large in size. The diagnosis of primary hyperfunctioning thyroid carcinoma is based on the following criteria: i) No improvement in thyrotoxicosis following radioactive iodine (RAI) treatment; ii) development of hypoechoic solid nodules with microcalcifications on ultrasound examination; iii) increase in tumor size over a short time period; iv) fixation of the tumor to adjacent structures; and v) signs/symptoms of tumor invasion. The diagnosis of metastatic hyperfunctioning thyroid carcinoma should be considered in patients suffering from thyrotoxicosis who present with a high number of metastatic lesions (as determined by whole-body scanning), or a history of total thyroidectomy. Surgery is the first-line treatment option for patients with primary hyperfunctioning thyroid carcinoma, as it does not only confirm the diagnosis following pathological examination, but also resolves thyrotoxicosis and is a curative cancer treatment. RAI is a suitable treatment option for patients with hyperfunctioning thyroid carcinoma who present with metastatic lesions.

A solitary hyperfunctioning thyroid nodule harboring thyroid carcinoma: review of the literature

Hyperfunctioning nodules of the thyroid are thought to only rarely harbor thyroid cancer, and thus are infrequently biopsied. Here, we present the case of a patient with a hyperfunctioning thyroid nodule harboring thyroid carcinoma and, using MEDLINE literature searches, set out to determine the prevalence of and characteristics of malignant “hot” nodules as a group. Historical, biochemical and radiologic characteristics of the case subjects and their nodules were compared to those in cases of benign hyperfunctioning nodules. A literature review of surgical patients with solitary hyperfunctioning thyroid nodules managed by thyroid resection revealed an estimated 3.1% prevalence of malignancy. A separate literature search uncovered 76 cases of reported malignant hot thyroid nodules, besides the present case. Of these, 78% were female and mean age at time of diagnosis was 47 years. Mean nodule size was 4.13 ± 1.68 cm. Laboratory assessment revealed T₃ elevation in 76.5%, T₄ elevation in 51.9%, and subclinical hyperthyroidism in 13% of patients. Histological diagnosis was papillary thyroid carcinoma (PTC) in 57.1%, follicular thyroid carcinoma (FTC) in 36.4%, and Hurthle cell carcinoma in 7.8% of patients. Thus, hot thyroid nodules harbor a low but non-trivial rate of malignancy. Compared to individuals with benign hyperfunctioning thyroid nodules, those with malignant hyperfunctioning nodules are younger and more predominantly female. Also, FTC and Hurthle cell carcinoma are found more frequently in hot nodules than in general. We were unable to find any specific characteristics that could be used to distinguish between malignant and benign hot nodules.

Papillary thyroid carcinoma in an autonomous hyperfunctioning thyroid nodule: case report and review of the literature

BACKGROUND

Whereas thyroid nodules are less common among children than among adults, the anxiety generated by the finding of a thyroid nodule is high because 20% of nodules found in children contain thyroid cancer. Discovery of a nodule in the context of hyperthyroidism is usually comforting due to the presumption that the nodule represents a benign toxic adenoma.

SUMMARY

An 11-year-old girl presented with heavy menses, fatigue, and a right thyroid mass. Laboratory evaluation revealed elevated triiodothyronine and undetectable thyroid-stimulating hormone. Thyroid ultrasonography revealed a 3.5 cm nonhomogenous nodule, and scintigraphy was consistent with an autonomous hyper-functioning nodule. Fine-needle aspiration biopsy could not rule out malignancy, and patient underwent right hemithyroidectomy and isthmusectomy. Pathology was consistent with papillary thyroid carcinoma.

CONCLUSIONS

We report the discovery of papillary thyroid carcinoma in an autonomously hyperfunctioning nodule in an 11-year-old girl. Detection of an autonomously functioning thyroid nodule in children and adolescents does not exclude the possibility of thyroid carcinoma and warrants careful evaluation and appropriate therapy.

US Features of Thyroid Malignancy: Pearls and Pitfalls

Thyroid nodules are common and occur in up to 50% of the adult population; however, less than 7% of thyroid nodules are malignant. High-resolution ultrasonography (US) is commonly used to evaluate the thyroid gland, but US is frequently misperceived as unhelpful for identifying features that distinguish benign from malignant nodules. Microcalcifications are one of the most specific US findings of a thyroid malignancy. Other useful US features include a marked hypoechogenicity, irregular margins, and the absence of a hypoechoic halo around the nodule. Lymphadenopathy and local invasion of adjacent structures are highly specific features of thyroid malignancy but are less commonly seen. The number, size, and interval growth of nodules are nonspecific characteristics. Suspicious US features may be useful for selecting patients for fine-needle aspiration biopsy when incidental nodules are discovered and when multiple nodules are present. Common interpretative pitfalls that may lead to failure to recognize a malignancy include mistaking cystic or calcified nodal metastases for nodules in a multinodular thyroid, mistaking diffusely infiltrative thyroid carcinomas and multifocal carcinomas for benign disease, and failing to recognize microcalcifications in papillary thyroid cancer.