Thyroid Incidentaloma: An Evidence-based Assessment of Management Strategy

Retrospective Analyses of 18FDG-PET/CT Thyroid Incidentaloma in Adults: Incidence, Treatment, and Outcome in a Tertiary Cancer Referral Center

Background: A thyroid incidentaloma (TI) is an unexpected, asymptomatic thyroid lesion discovered during the investigation of an unrelated condition. The aim of the present study is to examine the incidence of ¹⁸Fluorodeoxyglucose (FDG)-positron emission tomography (PET) TI, the associated management strategies and the outcomes in a tertiary cancer referral center. Methods: This study involves a retrospective cohort study of 1003 patients with TI found on ¹⁸FDG-PET/CT scans performed between January 2010 and January 2020 for a nonthyroidal malignancy. The Kaplan-Meier method was used for survival analyses in patients concerning an underlying malignancy, with a prevalence of 5% or higher in this cohort. Logistic- and cox regression analyses were performed to analyze predictors of thyroid malignancy and mortality. A propensity score weighted method was used to control for baseline differences between the intervention (additional TI diagnostics) and control (no TI diagnostics) group. Results: FDG-positive TI occurred in 1.9% (1003/52,693) of the oncologic ¹⁸FDG-PET/CT scans performed in our center. Thyroid surgery was performed in 47 patients (6%) and a thyroid malignancy was detected in 31 of them, which is 66% of those who had an operation and 4% of all patients. During the follow-up (median 6 years), 334 deaths (42%) related to different types of cancer (38%) or other causes (4%) were observed. One patient died from medullary thyroid cancer. In multivariate analysis adjusted for age, gender and the type- and stage of nonthyroidal malignancy, were independent predictors of survival (P < .05). Conclusions: The incidence of TI in this tertiary cancer referral center was comparable to current literature. Further thyroid workup was performed in less than half of the patients, and only a minority of patients underwent thyroid surgery. Since only one patient died from thyroid cancer, the strategy to withhold from thyroid diagnostics and treatment seems valid for most TI. Active thyroid treatment might benefit a subgroup of patients in whom the primary nonthyroidal malignancy is successfully treated or presumably stable. A wait-and-see policy with ultrasound follow-up could be an alternative strategy. These considerations should be part of the shared decision making in cancer patients with a TI.

Evaluation and management of thyroid incidentalomas detected prior to the parathyroid surgery

BACKGROUND

We investigated the management of thyroid incidentalomas associated with cases of parathyroid lesions in order to suggest a practical approach to their management from a surgical point of view.

METHODS

639 patients underwent radiological and ultrasound investigation of the thyroid area because of parathyroid disorders and parathyroidectomy and had at least three years of follow-up. All follow-up data for these cases were investigated from the moment the lesion was detected and up to the last report.

RESULTS

Out of 639 cases, incidental or asymptomatic thyroid nodules were found in 179 patients (28%), of which, 22 patients were operated (parathyroidectomy + thyroidectomy) and 157 remained with the nodules. For these patients, the average period of follow-up was 7 years 5 mo. Following the results of the follow-up, 52 patients (33%) were suggested to have surgery of the thyroid gland and 49 were operated (16 total thyroidectomies and 33 hemithyroidectomies). The complications after the second surgery included recurrent laryngeal nerve palsy (n = 3), superior laryngeal nerve palsy (n = 1), permanent hypocalcaemia (n = 8), and surgical damage to the internal jugular vein (n = 1). All complications occurred at the previously operated side of the neck.

CONCLUSION

While surgery remains the management of choice for malignant thyroid incidentalomas, for benign cases, if an asymptomatic thyroid nodule was detected inside the thyroid lobe on the side of planned parathyroidectomy and if the size of the nodule is ˃1.5 cm we suggest combined parathyroidectomy + hemithyroidectomy.

The Incidental Thyroid Lesion in Parathyroid Disease Management

Objective

The incidental thyroid lesion is a common finding during general imaging studies. Their management has been the subject of numerous studies and recommendations. Parathyroid disease workup necessitates imaging investigation of the adjacent thyroid gland and therefore provides a unique window to the perioperative management of thyroid incidentaloma. The specific prevalence of incidental thyroid lesions in the context of parathyroid disease is unknown. We seek to investigate its prevalence during parathyroid workup and surgery and to ascertain if there was a change in management of these patients.

Study Design

Five-year retrospective database review.

Setting

Tertiary care medical center.

Subjects and Methods

The source and indication for referral, preoperative investigation findings, and management of the incidental thyroid lesions were examined. The actual procedure performed and final pathology results were assessed.

Results

A total of 98 patients and 106 operations, including revision surgeries, were identified. There were 21 incidental thyroid lesions (21.4%) detected, whereby 15 patients underwent fine-needle aspirations and 12 subsequently had diagnostic hemithyroidectomies. This decision was made preoperatively in 5 patients and intraoperatively in 7 patients at the time of parathyroid surgery. Along with other pathologies, there were 7 patients with micropapillary thyroid carcinoma identified.

Conclusions

In our series, the prevalence of incidental thyroid lesion and thyroid malignancy is comparable to the general population. The management of the initial parathyroid disease in our patients was altered by the imaging and cytological findings of these thyroid lesions. This has implications on perioperative counseling of the thyroid and parathyroid disease.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ASSOCIAZIONE MEDICI ENDOCRINOLOGI MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE DIAGNOSIS AND MANAGEMENT OF THYROID NODULES--2016 UPDATE

Thyroid nodules are detected in up to 50 to 60% of healthy subjects. Most nodules do not cause clinically significant symptoms, and as a result, the main challenge in their management is to rule out malignancy, with ultrasonography (US) and fine-needle aspiration (FNA) biopsy serving as diagnostic cornerstones. The key issues discussed in these guidelines are as follows: (1) US-based categorization of the malignancy risk and indications for US-guided FNA (henceforth, FNA), (2) cytologic classification of FNA samples, (3) the roles of immunocytochemistry and molecular testing applied to thyroid FNA, (4) therapeutic options, and (5) follow-up strategy. Thyroid nodule management during pregnancy and in children are also addressed. On the basis of US features, thyroid nodules may be categorized into 3 groups: low-, intermediate-and high-malignancy risk. FNA should be considered for nodules ≤10 mm diameter only when suspicious US signs are present, while nodules ≤5 mm should be monitored rather than biopsied. A classification scheme of 5 categories (nondiagnostic, benign, indeterminate, suspicious for malignancy, or malignant) is recommended for the cytologic report. Indeterminate lesions are further subdivided into 2 subclasses to more accurately stratify the risk of malignancy. At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data, US signs, elastographic pattern, or results of other imaging techniques to improve the management of these lesions. Most thyroid nodules do not require any treatment, and levothyroxine (LT4) suppressive therapy is not recommended. Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while US-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules. Surgery remains the treatment of choice for malignant or suspicious nodules. The present document updates previous guidelines released in 2006 and 2010 by the American Association of Clinical Endocrinologists (AACE), American College of Endocrinology (ACE) and Associazione Medici Endocrinologi (AME).

Evaluation of clinical presentation and referral indications for ultrasound-guided fine-needle aspiration biopsy of the thyroid as possible predictors of thyroid cancer

BACKGROUND

Whether initial clinical presentation and thyroid ultrasonography referral indications can significantly predict malignant/suspicious for malignancy (Bethesda System for Reporting Thyroid Cytopathology [Bethesda] V/VI) thyroid ultrasound-guided fine-needle aspiration (FNA) cytology results is unknown.

METHODS

Between January 2010 and May 2014, we performed 705 thyroid ultrasound-guided FNA biopsies, according to the American Thyroid Association (ATA) guidelines. Univariate analysis was used to identify significant predictors for Bethesda V/VI thyroid ultrasound-guided FNA cytology, including age, sex, imaging modality, thyroid dysfunction, neck pain, breathing difficulties, dysphagia, odynophagia, fatigue, lateral cervical mass, parotid mass, and hyperparathyroidism.

RESULTS

Sixty percent of patients were referred to thyroid ultrasound-guided FNA because of thyroid incidentalomas and 40% because of palpable thyroid nodules found on physical examination. Only positron emission tomography (PET)-CT emerged as being a significant predictor for Bethesda V/VI thyroid ultrasound-guided FNA cytology (odds ratio [OR] = 5.64; 95% confidence interval [CI] = 1.16-27.33; p = .03).

CONCLUSION

Patient symptomatology and initial clinical thyroid ultrasound-guided FNA referral indications cannot predict the nature of thyroid nodules. © 2015 Wiley Periodicals, Inc. Head Neck 38: E991-E995, 2016.

Assessing health-related quality of life in patients with benign non-toxic goitre

Health-related quality of life (HRQoL) assessments are increasingly used to evaluate treatment effects and to shape the delivery of value based care. Valid generic and disease specific tools are available for quantifying HRQoL in patients with non-toxic goitre. However, few studies have applied these validated instruments to assess HRQoL in patients with benign non-toxic goitre. Limited evidence suggests that patients with non-toxic goitre have HRQoL impairments in multiple HRQoL domains. While the HRQoL-impact of non-toxic goitre may be small relative to other severely disabling medical conditions, treatment is almost exclusively elected for HRQoL indications. Thus better quantification of HRQoL, particularly at better (or more favorable) levels where many patients score, is essential. Web and mobile technologies have eased the ability to deliver surveys to patients. Routine consideration of HRQoL provides the opportunity to monitor the impact of treatment on the outcomes most meaningful for patients and the opportunity to help shape the delivery of value based health care.

Does elastography reduce the need for thyroid FNAs?

OBJECTIVE

Ultrasound elastography (USE) assesses lesion stiffness by evaluating tissue distortion in response to stress; it is emerging as a potentially useful tool to augment the ultrasound characterisation of thyroid nodules. The aim of this study was to assess the accuracy of USE examination of thyroid nodules compared with pathological outcome, especially to determine whether USE could reliably detect benign nodules and reduce the numbers of ultrasound guided fine needle aspiration cytology (USgFNAC).

DESIGN

Over a three-year period, thyroid nodules were initially characterised by B-mode ultrasound (US) findings. Where USgFNAC was indicated by clinical concern and/or the sonographic appearances, the lesion was then subjected to USE by an experienced operator prior to the USgFNAC.

PATIENTS

147 thyroid nodules were examined by USE and USgFNAC in 146 patients.

MEASUREMENTS

The elastographic appearance was subjectively categorized at the time of the examination (soft, intermediate or hard) and subsequently compared with the cytological/histological outcome.

RESULTS

A total of 122 nodules were non-neoplastic, 5 nodules were benign neoplasms, 10 nodules had indeterminate cytology and 10 were malignant neoplasms. The sensitivity of USE for malignancy was 90.0%, specificity was 79.6%, PPV was 24.3%, NPV was 99.1% and accuracy was 80.3%.

CONCLUSION

Thyroid nodules that are soft at USE have a high likelihood of being non-neoplastic and subjective USE assessment of thyroid nodules by an experienced operator can be a useful means of avoiding USgFNAC for benign nodules. In contrast, we suggest that all nodules that are intermediate or hard on USE undergo USgFNAC.

Positron emission tomography detected thyroid incidentaloma

We describe the case of a 48-year-old woman who presented with a thyroid lesion incidentally detected on positron emission tomography/computed tomography for a suspicious lung lesion. Subsequent clinical examination and investigations revealed a 3cm nodule in the left lower pole of the thyroid. Fine needle aspiration was indeterminate for malignancy. A left hemithyroidectomy was performed and histology confirmed a benign thyroid adenoma with an incidental micropapillary carcinoma. The literature regarding the best management for thyroid incidentalomas remains uncertain and, as such, each patient must be managed on an individual basis.

Role of ultrasonographic/clinical profile, cytology, and BRAF V600E mutation evaluation in thyroid nodule screening for malignancy: a prospective study

CONTEXT

Ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) is the most reliable nonsurgical test for distinguishing benign from malignant thyroid nodules. However, there is no consensus on which nodules should undergo FNAB.

AIMS

The aims of this study were to evaluate the utility of US-guided FNAB in the diagnostic assessment of nodules with or without clinical/US features suggestive for malignancy and to investigate the additional contribution of BRAF V600E mutation analysis in the detection of differentiated thyroid cancer.

DESIGN AND METHODS

Thyroid cytoaspirates from 2421 nodules at least 4 mm in diameter were performed in 1856 patients who underwent cytological evaluation and biomolecular analysis.

RESULTS

Cytology showed high positive predictive value and specificity for the diagnosis of malignant lesions. BRAF V600E mutation was found in 115 samples, 80 of which were also cytologically diagnosed as papillary thyroid cancer. BRAF mutation analysis significantly enhanced the diagnostic value of cytology, increasing FNAB diagnostic sensitivity for malignant nodules by approximately 28%. Micro PTC (63% of diagnosed papillary thyroid carcinoma) showed a high prevalence of multifocality, extrathyroidal extension, and lymph node metastases, underlining the malignant potential of thyroid microcarcinomas. Each investigated US/clinical characteristic of suspected malignancy correlated with the presence of a thyroid cancer in thyroid nodules with diameter of at least 4 mm.

CONCLUSIONS

These data indicate that nodules of at least 4 mm may underlie a thyroid cancer independently of US/clinical characteristics of suspected malignancy, suggesting the need to perform FNAB. The diagnostic sensitivity for thyroid cancer is significantly increased by BRAF V600E mutation analysis, indicating that the screening for BRAF mutation in FNAB samples has a relevant diagnostic potential.

[Incidental differentiated thyroid carcinoma is less prevalent in Graves' disease than in multinodular goiter]

OBJECTIVE

Risk factors for differentiated thyroid carcinoma (DTC) are poorly understood, but serum TSH levels, thyroid nodularity, and presence of autoimmunity are well-recognized factors that modulate DTC prevalence. TSH stimulates proliferation of both normal and neoplastic follicular cells. Consequently, thyroid-stimulating immunoglobulins (TSI), because of its TSH-like action, should induce DTC progression in patients with Graves' disease (GD). The study objective was to compare the prevalence of incidental DTC in patients undergoing thyroidectomy for benign thyroid disease.

METHODS

The pathology reports of 372 patients with preoperative diagnosis of euthyroid multinodular goiter (EMG) or hyperthyroidism were reviewed. Scintigraphy results and serum TSI levels were used to diagnosed either GD or hyperactive MG (HMG) to hyperthyroid subjects. Prevalence of DTC in each category was calculated using a Chi-square test.

RESULTS

EMG, GD, and HMG were diagnosed in 221, 125, and 26 patients. There were 58 DTCs, distributed as follows [n (%)]: EMG, 49 (22.2%); GD, 8 (6.4%), and HMG, 1 (3.8%). Difference in prevalence of incidental DTC between the groups was statistically significant (p<0.001). After adjustment for age, patients with EMG had a greater DTC prevalence than GD patients, with an OR of 4.17 (p<0.001). Tumor size (mm, mean ± SD) was 6.92 ± 11.26, 1.97 ± 1.85, and 9.0 for EMG, GD and HMG respectively (p=0.017).

CONCLUSIONS

Incidental DTC was less prevalent in GD as compared to EMG irrespective of age. This finding may suggest a predisposition to develop DTC in patients with thyroid nodular disease and/or a potential effect of autoimmunity to protect against development of neoplastic disease.

Evidence-based endocrinology: illustrating its principles in the management of patients with pituitary incidentalomas

Incidentally discovered pituitary lesions are commonly encountered in the current era of ever-increasing imaging. Individualizing a particular approach implies a thorough analysis of existing evidence and balancing it against different patient expectations. We will illustrate the application of principles of Evidence-Based Medicine to a case of a pituitary incidentaloma by formulating questions that are important to patient care and finding related evidence. Our objective is to reflect the opportunities and the challenges that an evidence-based clinical approach offers to clinicians and patients.

The role of 18F-fluorodeoxyglucose positron emission tomography in thyroid neoplasms

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has established itself as an important imaging modality in many oncological and nononcological specialties and, as a consequence, it is increasingly being used in clinical practice. Since the first report of FDG being taken up by metastatic differentiated thyroid carcinoma (DTC) cells >20 years ago, various groups of investigators have explored the potential role of FDG-PET scanning in patients with benign and malignant thyroid neoplasms. With the increasing demand for FDG-PET scanning, clinicians are faced with the challenge of managing an increasing number of FDG-PET-detected thyroid incidentalomas because their significance remains unclear. The aims of this review are to address some of these issues, specifically, the clinical significance of FDG-PET-detected thyroid incidentalomas, the ability of FDG-PET to characterize thyroid nodules, especially those with indeterminate fine needle aspiration cytology results, and the role of FDG-PET in patients with confirmed primary DTC and with suspected recurrent DTC, by reviewing the current literature.

Presentation of clinically solitary thyroid nodules in surgical patients

BACKGROUND

Thyroid nodules occupy a unique position in relation to clinical diagnosis since most patients with a thyroid nodule do not present with overt symptoms. There are, however, no good published data demonstrating the way in which clinically solitary thyroid nodules come to medical attention, with most of the literature being anecdotal. This study aims to evaluate the mode of presentation of solitary thyroid nodules, and to assess whether the presence of a malignancy influences that presentation.

METHODS

In this retrospective cohort study, data were obtained from the University of Sydney Endocrine Surgery Database and through a review of the patient records. The study cohort comprised 419 consecutive patients who presented with a clinically solitary thyroid nodule and who subsequently underwent surgery. Patient files lacking data on mode of presentation and patients in whom thyroid nodules were incidentally discovered during parathyroid surgery were excluded, leaving a total of 299 patients. Data were analyzed using a computer-based statistical software package. Continuous variables were compared using Student's t-test. Categorical variables were analyzed using Fishers exact test. Statistical significance was set at p < 0.05.

RESULTS

Solitary thyroid nodules are most commonly detected by the patients themselves (40%), followed by the incidental discovery of nodules on imaging studies performed for unrelated reasons (30%), and lastly due to third-party diagnosis by family, friends, acquaintances, or medical practitioners (30%). Nodules detected by medical practitioners were statistically more likely to be malignant (p = 0.02). No other differences between the clinical presentation of benign and malignant nodules were found.

CONCLUSIONS

Patients themselves are the ones who most commonly first become aware of the thyroid nodules that are eventually seen by thyroid surgeons. Incidental discovery on image studies is also important. Thyroid nodules detected by medical practitioners should be dealt with most urgently because they are most likely to be malignant.

Incidental thyroid abnormalities identified on neck US for non-thyroid disorders

BACKGROUND

Incidental thyroid abnormalities detected on US examinations in children have not been well documented.

OBJECTIVE

To determine prevalence of incidental thyroid abnormalities depicted by US in children and to describe the spectrum of appearances.

MATERIALS AND METHODS

Retrospective analysis of clinical and US findings in children who had neck US from January 2006 to December 2007.

RESULTS

Of 1,228 neck US exams, thyroid was depicted in 287 children (mean age = 6.2 years). Incidental thyroid abnormalities were detected in 52 (18%) (mean age = 8.1 years). In 35 there were small (<4 mm), well-defined cysts, some with a hyperechoic punctate focus. In nine there were hypoechoic, solid nodules with smooth, straighter margins with echogenicity similar to thymus, suggesting intrathyroid ectopic thymus (mean age = 2.5 years). In three others there were tiny hyperechoic foci without nodules. Other abnormalities included hypoechoic target-like lesions (n = 2), isoechoic nodule (n = 1), multiple hypoechoic foci (n = 1) and non-visualized thyroid lobe resulting from adjacent abscess (n = 1). None of the children developed thyroid dysfunction or malignancy.

CONCLUSION

There is a spectrum of incidental thyroid abnormalities in children. These US findings should be interpreted cautiously, avoiding unnecessary referrals and investigations. Intrathyroid ectopic thymus is more common than previously thought, occurs much more frequently in younger boys and should be considered if the lesion has US characteristics of thymus.

Management of thyroid nodules and surgery for differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades. Whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains unclear. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients. Level 1 evidence is lacking, and there are limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. This overview focuses on the major issues associated with the investigation of thyroid nodules and the extent of surgery. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. The onus is on the physician to avoid treatment-related complications from thyroid surgery and to offer the most efficient and cost-effective therapeutic option.

Thyroid incidentalomas: to treat or not to treat

Incidental lesions of the thyroid gland are an increasing problem facing clinicians. While asymptomatic palpable lesions are detected in only 4-7% of the population, currently available imaging modalities are sensitive enough to detect lesions in 20-30% of the population. Guidelines for managing these incidentalomas are limited, largely due to lack of well-powered prospective studies. This review will address the currently available data on thyroid incidentalomas, detected through clinical examination, cross-sectional imaging, ultrasound, and PET scans. We will focus on the modalities of detection and risk of malignancy, further investigation and management options and the deficiencies therein. We propose a pragmatic algorithm when faced with this clinical dilemma under differing circumstances.

Controversies and challenges in the management of well-differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades, although whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains undetermined. Nonetheless, this rising incidence has fuelled an interest in early diagnosis, treatment and follow-up of thyroid cancer along with greater public awareness. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients, and there is limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. The major controversies are related to diagnostic work-up, extent of surgery and postoperative management including the role of radioactive iodine. There are also differences in opinion regarding management of nodal metastases and follow-up protocols. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. There needs to be a concerted effort on the part of a multidisciplinary team to recognise the nuances in treating well-differentiated thyroid cancer.