Incidental Thyroid Lesions Research Articles

Ultrasound and cytological evaluation of PET-CT positive incidental thyroid lesions

Ultrasound and cytological evaluation of PET-CT positive incidental thyroid lesions

Characteristics of malignant thyroid lesions on [18F] fluorodeoxyglucose (FDG)-Positron emission tomography (PET)/Computed tomography (CT)

ObjectivesTo determine the imaging variables that can best differentiate malignant from benign thyroid lesions incidentally found on F-18 FDG PET/CT scans. MethodsAll F-18 FDG PET/CT studies starting from 2011 to end of 2016 were reviewed for incidental thyroid lesions or metabolic abnormalities. Only patients who were found to have FNAB or histopathology were included. Patients with known thyroid malignancy were excluded. Patients were analyzed for age, sex, SUVmax, non-enhanced CT tissue density in mean Hounsfield units (HU), uptake pattern (focal or diffuse) and gland morphology (MNG or diffuse). A control group of 15 patients with normal thyroid glands were used to assess the tissue density in HU for normal thyroid tissue. Sensitivity, specificity, PPV, NPV and accuracy to detect malignancy were calculated. Pearson Chi-square test was used to compare categorical variables while unpaired T-test and one way ANOVA test were used to compare means of continuous variables. ROC analysis was used to assess the best cut off points for SUVmax and HU. Regression analysis was used to detect the independent predictors for malignant lesions. ResultsBiopsy was unsatisfactory or indeterminate in 4/48 patients (8%). Only 44 patients (mean age 55.2 ± 14.7; 30 females (68 %)) with unequivocal FNAB or histopathology were included for further analysis. MNG was noted in 17/44 patients (38.6 %). Thyroid malignancy was found in 16/44 (36.4 %), benign thyroid lesions in 28/44 (63.6 %). Thyroid malignancies were 12 papillary, 1 follicular, 1 Hurthle cell neoplasm and 2 lymphoma. Benign lesions were 23 benign follicular or colloid nodules and 5 autoimmune thyroiditis. Focal FDG uptake pattern was more frequently associated with malignant lesions compared to benign lesions (75 % vs. 43 %; p = 0.039). The mean SUVmax and tissue density (HU) were both higher in malignant than benign lesions (8.8 ± 8.3 vs. 3.6 ± 1.9, p = 0.024) and (48.9 ± 12.7 vs. 32.9 ± 17.5, p = 0.003) respectively. The mean HU in the control group with normal thyroid tissue was 90 ± 7.4 significantly higher than in both the benign and malignant lesions (p < 0.001). ROC analysis revealed SUVmax cutoff of >4.7 and HU cutoff of >42 to best differentiate malignant from benign lesions. The sensitivity, specificity, PPV, NPV and accuracy to detect malignancy for SUVmax>4.7 were 68.8 %, 78.6 %, 64.8 %, 81.5 & 75.0 % (p = 0.002), for HU > 42 were 81.3.0 %, 75.0 %, 65.0 %, 87.5 & 77.3 % (p = 0.0003) and for both parameters combined were 87.5 %, 60.7 %, 56.0 %, 89.5 % and accuracy of 70.5 % (p = 0.002) respectively. Only HU > 42 and SUVmax>4.7 were independent predictors for malignancy with odd ratios 8.98 and 4.93 respectively. ConclusionA higher tissue density (HU > 42) and SUVmax>4.7 as well as tendency for focal uptake pattern are the most significant characteristics associated with malignant thyroid lesions occasionally detected on PET/CT.

Audit of carotid doppler sonography: Spectrum of findings at a tertiary hospital in Northwestern Nigeria.

Introduction:Doppler sonography of the cervical segment of the carotid arteries is becoming a popular tool for evaluating atherosclerosis of the carotid artery. We present the audit of findings on carotid ultrasound examination among patients with clinical suspicion and risks for cerebrovascular disease and possible correlates in Northern Nigeria.Materials and Methods:We performed carotid ultrasound examination on all patients referred for screening and clinical suspicion of cerebrovascular disease within the year 2017. The patients' characteristics, risk factors, presence of atheroma and characteristic of the atheroma, degree of stenotic disease as well as the presence of incidental ultrasound findings were reviewed and documented.Results:Out of the 62 patients, 55 (88.7%) of them had various degrees and types of atheromatous plaques in different segments of the cervical carotid arteries, whereas 7 (11.3%) were normal. The predominant risk factor was smoking followed by diabetes mellitus, whereas the highest indication for the scan was transient ischemic attack. Incidental thyroid lesions such as nodules and cysts were encountered in 14 (22.6%) of the patients. There is a statistically significant difference between sex and age with the side of lesion, degree of stenosis, segment involved, and type of atheromatous plaque.Conclusion:There is a statistically significant difference between sex and age with the side of lesion, degree of stenosis, segment involved, and type of atheromatous plaque. About one-fifth of our patients had incidental thyroid lesions. Therefore, routine screening of population at risk is highly recommended.

Evaluation of Incidental Thyroid Findings Detected by Positron Emission Tomography/Computed Tomography

AbstractBackground: Thyroid incidenteloma detected on 18F-FDG PET/CT carries a high risk of malignancy. This high risk of malignancy supports the performance of a further diagnostic procedure, such as ultrasonography and fine needle aspiration biopsy.Aim of Study: To determine the role of PET/CT in evalu-ation of incidental thyroid lesions detected in patients being studied for lymphomas and/or cancers other than of thyroid.Material and Methods: This study included thirty four patients with incidental abnormal increased FDG uptake. All patients were subjected to ultrasound examination and patients with focal increased tracer uptake were subjected to fine needle aspiration biopsy.Results: This study included a total of 1263 consecutive patients who underwent a FDG PET/CT study for staging of an advanced cancer of any site of the body other than the thyroid gland during the period. An incidental abnormal increase in FDG uptake in the thyroid gland was observed in 39 (3.08%) patients. Out of these patients, 26/39 (66.6%) presented with a focal and 13/39 (33.4%) with a diffuse thyroid uptake giving a prevalence of 2.06% for focal uptake and 1.03% for diffuse uptake. Six patients out of 23 patients with focal abnormal thyroid uptake were proven to have thyroid malignancy (Four patients with papillary thyroid carcinoma, one patient with follicular thyroid carcinoma and the remaining patient with atypical Hurthle cells). Thus the malignancy rate in patients with thyroid incidentalomas which proceeded to tissue biopsy was about 26%.Conclusion: An incidental focal uptake of 18F-FDG in the thyroid gland is of significant risk of malignancy. A high value of SUVmax increases the risk of malignancy and SUVmax does not correlated with the diameter of malignant lesions, so FDG-PET/CT can detect malignancy in small thyroid lesions.

The assessment of incidental thyroid lesions on 18F-fluorodeoxyglucose positron emission tomography/computed tomogrophy: A single centre experience

Abstract Objective The aim of the present study was to evaluate the prevalence of thyroid lesions detected by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) incidentally, determine malignancy risk and its relationship with maximal standardized uptake value (SUVmax) and FDG uptake pattern. Methods Between February 2009 and February 2014, a total of 12713 patients underwent 18F-FDG PET/CT. Incidental thyroid uptake was seen in 710 patients and further diagnostic evaluation was performed on 147 patients with focal or diffuse FDG uptake. The 18F-FDG PET/CT findings of these patients and their association with malignancy were retrospectively reviewed. Results The prevalence of thyroid incidentalomas detected by 18F-FDG PET/CT was 5.6% (710/12713). Of the 147 patients who underwent biopsy or thyroid surgery, histology was benign in 99 and malign in 48 patients. The malignancy risk of incidental thyroid lesions was calculated as 32.7% (48/147). The median SUVmax was 2.9 (0.6–27.4) in benign group, whereas 11.8 (2.4–72.9) in malign group and the difference between these groups was statistically significant (p Conclusion The malignancy risk of incidental thyroid lesions on 18F-FDG PET/CT is high. Although it is obvious that higher SUVmax values are tended to be malign, an overlap between benign and malign groups is still remaining. In case of absence of clinical contraindications, further examination should be recommended.

The Incidental Thyroid Lesion in Parathyroid Disease Management.

ObjectiveThe 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 DesignFive-year retrospective database review.SettingTertiary care medical center.Subjects and MethodsThe 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.ResultsA 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.ConclusionsIn 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.

Prevalence of incidental thyroid pathology: Preliminary results of a post-mortem study

Introduction Incidental thyroid lesions are diagnosed with increased frequency by sophisticated imaging techniques; however, Sri Lanka lacks data on the prevalence of incidental thyroid pathology. The objective of this study was to determine the prevalence of incidental thyroid pathology in Sri Lanka. Methodology Consecutive autopsies of which the death was due to undiagnosed acute diseases or trauma, conducted at the Institute of Forensic Medicine and Toxicology, Colombo, from 2014-2016 were included. Informed written consent and a brief history were obtained from next of kin. Gross examination and microscopic examination of grossly normal and adequately sampled abnormal thyroid tissue was done by a histopathologist. Results Data was obtained from 248, including 174(70.2%) males and 74(29.8%) females of which eight were excluded due to unavailability of the thyroid. The mean age was 52.6 years (SD=16.9). None had a history of thyroid disease. One had a family history of thyroid carcinoma. At least one pathology was seen in 136/240(56.7%): papillary microcarcinoma (PMC) in 25(10.4%), colloid nodules in 72(30%), hyperplastic nodules in 6(2.5%), chronic autoimmune thyroiditis (CAT) in 52(21.7%). PMC was equally prevalent in males (10.5%) and females(10%) with no association with age (p>0.05). CAT was diffuse in 31(12.9%) and focal in 21(8.8%). Prevalence of CAT among females (63.4%, 33/52) was significantly higher than males (36.6%- 19/52)(p Discussion and Conclusion The commonest pathology found was colloid nodules. The prevalence of undiagnosed papillary microcarcinoma and chronic autoimmune thyroiditis was considerably high. Similar to other studies, prevalence of chronic autoimmune thyroiditis was significantly higher in females than males. Prevalence of papillary microcarcinoma falls in between the lowest, 0.01% in USA and highest, 35.6% in Finland, reported in literature.

Thyroid Nodules Detected by Contrast-Enhanced Magnetic Resonance Angiography: Prevalence and Clinical Significance

Background and PurposeIncidental thyroid lesions are frequently found on contrast-enhanced magnetic resonance (CE-MR) angiography. The purpose of this study is to determine the prevalence of thyroid incidentalomas detected by CE-MR angiography and to evaluate their clinical significance by correlation with ultrasound (US) and cytopathological results.Materials and MethodsWe retrospectively reviewed 3,299 consecutive CE-MR angiography examinations performed at our institution between January 2010 and March 2013. Two radiologists evaluated the CE-MR angiography imaging in consensus regarding the presence, location, and vascularity of thyroid incidentaloma. We correlated these findings with follow-up US and cytopathologic results.ResultsThe prevalence of thyroid incidentalomas detected by CE-MR angiography was 4.6% (152/3,299 patients). CE-MR angiography showed hypervascularity in 86.8% (145/167), isovascularity in 8.4% (14/167), and hypovascularity in 4.8% (8/167) of thyroid nodules compared to vascularity of thyroid parenchyma. Among the patients with thyroid incidentaloma, 34 patients (22.4%) were followed by US examination, and all 36 nodules on CE-MR angiography were detected on follow-up US. Of these nodules, 9 (25%) nodules were classified as probably benign, 26 (72.2%) as indeterminate, and 1 (2.8%) as suspicious malignant nodule. Among the 16 nodules with available cytopathologic results, 12 nodules were benign, 2 nodules were follicular neoplasm, and 2 nodules showed non-diagnostic results.ConclusionIncidental thyroid nodules were found in 4.6% of CE-MR angiography examinations. Because the high incidence of indeterminate US feature among thyroid incidentaloma, when a thyroid incidentaloma is detected on CE-MR angiography, further evaluation with US should be performed.

Diagnosis of incidental thyroid nodules on 18F-fluorodeoxyglucose positron emission tomography imaging: are these significant?

To determine the prevalence of thyroid malignancy in the first UK case series of patients with incidentally detected thyroid lesions on 18F-fluorodeoxyglucose positron emission tomography imaging. A total of 235 patients were evaluated with 18F-fluorodeoxyglucose positron emission tomography imaging. Incidental focal uptake in the thyroid gland was identified in nine patients (3.8 per cent). A retrospective review of their case notes was conducted. The rate of malignancy was 55 per cent. The mean and standard deviation of the maximum standardised uptake value was 13.1 ± 7.3 in those patients with malignancy and a nodule identified as positive on positron emission tomography. This value was 2.8 ± 1.2 in those patients without malignancy but with a nodule identified as positive on positron emission tomography (p = 0.01). A palpable thyroid nodule was more likely in those with malignant lesions (p = 0.14). The prevalence of incidental thyroid lesions found on 18F-fluorodeoxyglucose positron emission tomography in patients with other primary malignancies is low, but the incidence of malignancy in these patients is high. Patients with a palpable thyroid nodule, focal uptake on 18F-fluorodeoxyglucose positron emission tomography and an increased maximum standardised uptake value require further investigation.

Thyroid Lesions Visualized on CT: Sonographic and Pathologic Correlation

There are no definitive guidelines for the management of incidental thyroid lesions on computed tomography (CT). The objectives of our study were to assess the association between CT and ultrasound (US) characteristics of thyroid lesions and identify CT predictors of benignity or malignancy. Two hundred fifty-nine patients who had undergone both CT of the chest or neck and thyroid US had at least one thyroid lesion visible on CT; both incidentally detected and palpable or symptomatic lesions were included. The CT and US examinations were retrospectively reviewed and lesions characterized. Pathologic results from fine-needle aspiration (FNA) and surgical excision were used to classify lesions as benign or malignant. Thyroid lesions without pathologic correlation were classified as either benign or indeterminate based on US evaluation. Lesions that were cystic, predominantly cystic, solid and cystic with features consistent with a colloid nodule, or stable for at least 1 year were considered benign. Fisher exact tests, Spearman correlations, and logistic regression models were used to evaluate the associations between CT and US characteristics and CT predictors of benignity or malignancy. Multivariable logistic regression analyses were performed to examine the joint associations between the CT features and sonographically assessed benignity. Of 259 patients, 168 (64.9%) patients had incidentally detected thyroid lesions, 49 (18.9%) patients had palpable/symptomatic lesions, and 116 (44.8%) patients underwent surgical resection and/or FNA biopsy. The malignancy prevalence was 1.8% (3 of 168) for incidental thyroid lesions and 10.2% (5 of 49) for palpable/symptomatic lesions. The malignancy prevalence of incidental lesions initially detected on CT was 1.6% (2 of 125). Of the 143 patients without pathologic data, 58 (40.6%) were classified as benign and 85 (59.4%) were categorized as indeterminate based on US evaluation. Statistically significant associations were found between CT and US with regard to lesion number, dominant lesion size, lesion consistency/composition, and associated calcifications. No CT characteristics of thyroid lesions predicted malignancy. However, there were statistically significant associations on multivariate analysis between indeterminate/benign nodules and CT characteristics of smaller lesion size, lower mean attenuation, and homogeneous composition. Recommending sonographic evaluation of all incidentally detected thyroid lesions is likely not the appropriate strategy, given the high prevalence of thyroid incidentalomas, low probability of malignancy, and cost effectiveness of workup. Small, homogeneous, low-attenuation lesions have a high probability of being benign.

Incidental Thyroid Abnormalities on Carotid Color Doppler Ultrasound: Frequency and Clinical Significance

Background Thyroid nodules are often incidentally detected during physical examination, Doppler ultrasound of carotid artery, and other imaging modalities and there are many controversies about the management of these incidentalomas. We focused on incidental thyroid lesions during carotid ultrasound and evaluated their importance and suspected malignant features. Patients and methods The thyroid gland was evaluated for any nodule(s) following carotid Doppler ultrasound in 290 patients. If there was an abnormal finding in the thyroid ultrasound, the patient was referred to an endocrinologist and after clinical and laboratory evaluation, fine-needle aspiration (FNA) biopsy was done if required. Results We found an abnormal thyroid in 63 (21.8%) patients and 57 (19.6%) of patients had incidental thyroid nodules; these were mainly in women and older patients. Based on size and ultrasound findings of the nodules, 28 (44.4% of abnormal thyroids) patients were referred for fine-needle aspiration biopsy and 15 patients agreed with this procedure. Aspiration cytology showed two nondiagnostic samples (13.3%), 10 benign lesions (66.6%), two follicular cell lesions (13.3%), and one (6.6%) Hurthle cell neoplasm lesion. Conclusion Thyroid evaluation during carotid ultrasound has little benefits.

Prevalence of incidental thyroid nodules in ultrasound studies of dogs with hypercalcemia (2008-2013).

Ultrasound is commonly used to evaluate the cervical region in dogs with hypercalcemia due to suspected hyperparathyroidism. Incidental thyroid nodules may be detected during these studies, however little information has been published to guide clinical decision-making when this occurs. The purpose of this cross-sectional study was to determine the prevalence of incidental thyroid nodules in hypercalcemic dogs undergoing cervical ultrasound at our hospital during the period of 2008-2013. Dogs with a palpable neck mass were excluded. Cervical ultrasound images for each dog were retrieved and reviewed by a board certified veterinary radiologist who was unaware of patient outcome. Presence, number, and dimensions of thyroid nodules were recorded. Results of thyroid nodule aspirate, biopsy or necropsy were recorded from medical records when available. Ninety-one dogs met inclusion criteria. Of these, 14/91 (15%) dogs had at least one thyroid nodule. Mean (± standard deviation) thyroid gland nodule length, width, and height were 1.51 ± 0.74, 0.96 ± 0.73, and 0.75 ± 0.36 cm, respectively. A histologic diagnosis was available for the incidental thyroid lesions in eight dogs, including one dog with two nodules. Confirmed diagnoses for these nodules were thyroid cyst (3/9, 33%), thyroid adenoma (3/9, 33%), thyroid adenocarcinoma (2/9, 22%) and nodular hyperplasia (1/9, 11%). Findings indicated that incidental thyroid nodules may be present in hypercalcemic dogs with no palpable neck mass and no clinical signs of thyroid disease. Some of these nodules may be malignant and therefore a recommendation for cytology or biopsy may be justified.

The Proportion of Malignancy in Incidental Thyroid Lesions on 18-FDG PET Study: A Systematic Review and Meta-analysis.

To evaluate through a systematic review and meta-analysis the malignancy rates of thyroid incidentalomas identified in adults by 18-fluorodeoxyglucose positron emission tomography, computed tomography (18-FDG PET-CT) imaging studies. The literature search was conducted using OVID Medline, EMBASE, the Cochrane Library, Google Scholar, Pubmed, and reference list review (inception to April 2013) by 2 independent review authors. Studies with adults undergoing 18-FDG PET scan identifying a thyroid incidentaloma with definitive histological or cytological results reported were included. Thirty-one studies with a total of 197,296 PET studies and 3659 focal thyroid incidentalomas were identified with 1341 having definitive cytopathology or histopathology. The pooled proportion of malignancy was calculated as 19.8% (95% confidence interval [CI], 15.3%-24.7%) with 15.4% (95% CI, 11.4%-20.0%) of the total cases being papillary thyroid cancer. Distant metastases represented 1.1% (95% CI, 0.6%-1.8%) of the total cases. Our systematic review and meta-analysis suggests that the incidence of malignancy is high in thyroid incidentalomas identified through 18-FDG PET imaging studies. Thyroid incidentalomas identified through 18-FDG PET require thorough investigation.

Incidental Thyroid Lesions Detected on18F-Fluorodeoxyglucose Positron Emission Tomography/CT in Patients with Non-Thyroidal Cancer: Clinical Implications and the Value of Ultrasound

Incidental Thyroid Lesions Detected on¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/CT in Patients with Non-Thyroidal Cancer: Clinical Implications and the Value of Ultrasound

The Clinical Role of Dual-Time-Point (18)F-FDG PET/CT in Differential Diagnosis of the Thyroid Incidentaloma.

Thyroid incidentalomas are common findings during imaging studies including 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for cancer evaluation. Although the overall incidence of incidental thyroid uptake detected on PET imaging is low, clinical attention should be warranted owing to the high incidence of harboring primary thyroid malignancy. We retrospectively reviewed 2,368 dual-time-point 18F-FDG PET/CT cases that were undertaken for cancer evaluation from November 2007 to February 2009, to determine the clinical impact of dual-time-point imaging in the differential diagnosis of thyroid incidentalomas. Focal thyroid uptake was identified in 64 PET cases and final diagnosis was clarified with cytology/histology in a total of 27 patients with 18F-FDG-avid incidental thyroid lesion. The maximum standardized uptake value (SUVmax) of the initial image (SUV1) and SUVmax of the delayed image (SUV2) were determined, and the retention index (RI) was calculated by dividing the difference between SUV2 and SUV1 by SUV1 (i.e., RI = [SUV2 - SUV1]/SUV1 × 100). These indices were compared between patient groups that were proven to have pathologically benign or malignant thyroid lesions. There was no statistically significant difference in SUV1 between benign and malignant lesions. SUV2 and RI of the malignant lesions were significantly higher than the benign lesions. The areas under the ROC curves showed that SUV2 and RI have the ability to discriminate between benign and malignant thyroid lesions. The predictability of dual-time-point PET parameters for thyroid malignancy was assessed by ROC curve analyses. When SUV2 of 3.9 was used as cut-off threshold, malignancy on the pathology could be predicted with a sensitivity of 87.5 % and specificity of 75 %. A thyroid lesion that shows RI greater than 12.5 % could be expected to be malignant (sensitivity 88.9 %, specificity 66.3 %). All malignant lesions showed an increase in SUVmax on the delayed images compared with the initial images. But in the group of benign lesions, 37.5 % (6/16) showed a decrease or no change in SUVmax. Dual-time-point 18F-FDG PET/CT, obtaining additional images 2 h after injection, seems to be a complementary method for the differentiation between malignancy and benignity of incidental thyroid lesions.

Incidental thyroid lesions identified by ultrasound in patients with non-thyroidal head and neck cancer

Thyroid cancer is one of the common head and neck malignancies and may be found incidentally with other head and neck cancers. To evaluate the prevalence and risk of malignancy in incidental thyroid lesions identified by ultrasound (US) in patients with head and neck cancer. We retrospectively reviewed medical records of all patients with head and neck cancer other than of thyroid origin between January 2004 and December 2011. A total of 690 patients (537 men and 153 women; mean age, 58.9 ± 12.9 years) underwent US of the neck for the evaluation of cervical lymph node status (including thyroid gland). We evaluated the prevalence of patients with incidental thyroid lesions identified by US and the risk of malignancy in these patients. Of the 690 patients with head and neck cancer, 234 (33.9%) had incidental thyroid lesions on US. Based on US findings, 61 patients underwent fine-needle aspiration, with 39 eventually undergoing thyroidectomy. Among these thyroid lesions, 24 incidental thyroid lesions of 22 patients were histologically proven to be malignant (23 papillary and 1 follicular carcinomas). The risk of malignancy was 9.4% on a patient-by-patient basis. Screening of the thyroid gland should be included in the preoperative US examination for cervical lymph node metastases in patients with non-thyroidal head and neck cancer.

Simultaneous laryngeal squamous cell carcinoma and thyroid carcinoma in the contralateral lobe of a nonsmoker woman

AbstractWe report a 60-year-old nonsmoker woman with laryngeal squamous cell carcinoma for which total laryngectomy and right conservative neck dissection was decided. Right hemithyroidectomy is usually a part of this procedure, but in this case, because of inadvertent ligation of the left inferior thyroid artery, total thyroidectomy was performed. A small nodule 0.5 cm of papillary microcarcinoma in the left lobe that was not diagnosed preoperatively was discovered in the final pathological examination. Therefore, ultrasound evaluation of the thyroid gland should be added to the work-up of all cases undergoing total laryngectomy and there is a need for new guidelines to treat incidental thyroid lesions in the context of laryngeal cancer.

The Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in the Diagnosis of Incidental Thyroid Lesions

Objective: The aim of this study was to determine the diagnostic accuracy of incidental FDG-PET/CT uptake in the thyroid in patients with cancers of nonthyroidal origin, in order to reduce the number of thyroidectomies performed on nodules that subsequently proved to be benign. Material and methods: From January to September 2011 a total of 2510 patients were evaluated at our institution with whole-body FDG-PET. The studies were done for a variety of diagnoses including metastatic work-up for lymphoma, head and neck cancer, and other nonthyroidal malignant nodules. 30 patients were identified with incidental focal or diffuse uptake in thyroid bed. All patients underwent measurement of serum level of thyroid hormones and ultrasonography (US). While the patients with focal uptake underwent fine needle aspiration biopsy, FNAB. Results: PET incidentaloma was observed in 30 patients (0.12% of the whole population) with normal thyroid functions and there weren’t known clinical manifestations of thyroid disease. FDG PET uptake pattern was diffuse in 8 patients (26.7%) and focal in 22 patients (73.3%). SUVmax was included between 2.5 and 20. The patients with focal uptake underwent FNAB which demonstrated 4 patients with TIR1 (18.2%), 3 patients with TIR2 (13.6%), 11 patients with TIR3 (50%), 2 patients with TIR4 (9.1%), 1 patient with TIR5 (4.5) and 1 patient with TIR6 (4.5%). All 4 patients with TIR4, TIR5 and TIR6 underwent to thyroidectomy and the final diagnosis was papillary carcinoma. Conclusions: The results of this study suggest that incidentally found thyroid lesions by FDG-PET/CT, especially a focal FDG uptake and a high SUV, have a high probability of thyroid malignancy.

Does Routine Use of Ultrasound Result in Additional Thyroid Procedures in Patients with Primary Hyperparathyroidism?

Minimally invasive parathyroidectomy for primary hyperparathyroidism depends on accurate preoperative imaging. Cervical ultrasound is commonly used to localize parathyroid adenomas, but can lead to discovery of concomitant thyroid gland pathology requiring modification of the operative approach. How the identification of incidental thyroid lesions affects patient management is unclear. A prospective database of patients undergoing parathyroidectomy was analyzed for thyroid pathology discovered by ultrasound. Lesions were biopsied if indicated, and operative management was adjusted accordingly. Clinical data were correlated with operative decision-making. Between July 2002 and November 2009, 310 patients with primary hyperparathyroidism underwent ultrasound. Concomitant thyroid pathology was noted in 89 (29%) patients. Thirty-seven patients (42% of pathology) underwent fine-needle aspiration of a thyroid nodule. Thirteen patients (4% of all patients) underwent a thyroid operation not related to parathyroid disease: 9 thyroid lobectomies for presumably benign nodules and 4 total thyroidectomies for malignancy. Two were for confirmed papillary thyroid cancer, and the other 2 were for an indeterminate biopsy that later proved to be papillary thyroid cancer. One lobectomy discovered microscopic papillary thyroid cancer independent of the biopsied nodule. In total, 5 (2% of all patients) malignancies were discovered. Twenty-nine percent of patients with primary hyperparathyroidism had concomitant thyroid pathology on ultrasound. Forty-two percent of these patients underwent biopsy, and 2% had malignant pathology. Routine use of ultrasound in patients with primary hyperparathyroidism leads to discovery of unrecognized thyroid pathology and cancer.

Incidental thyroid lesions detected by FDG-PET/CT: prevalence and risk of thyroid cancer

BackgroundIncidentally found thyroid lesions are frequently detected in patients undergoing FDG-PET/CT. The aim of this study was to investigate the prevalence of incidentally found thyroid lesions in patients undergoing FDG-PET/CT and determine the risk for thyroid cancer.MethodsFDG-PET/CT was performed on 3,379 patients for evaluation of suspected or known cancer or cancer screening without any history of thyroid cancer between November 2003 and December 2005. Medical records related to the FDG-PET/CT findings including maximum SUV(SUVmax) and pattern of FDG uptake, US findings, FNA, histopathology received by operation were reviewed retrospectively.ResultsTwo hundred eighty five patients (8.4%) were identified to have FDG uptake on FDG-PET/CT. 99 patients with focal or diffuse FDG uptake underwent further evaluation. The cancer risk of incidentally found thyroid lesions on FDG-PET/CT was 23.2% (22/99) and the cancer risks associated with focal and diffuse FDG uptake were 30.9% and 6.4%. There was a significant difference in the SUVmax between the benign and malignant nodules (3.35 ± 1.69 vs. 6.64 ± 4.12; P < 0.001). There was a significant correlation between the SUVmax and the size of the cancer.ConclusionThe results of this study suggest that incidentally found thyroid lesions by FDG-PET/CT, especially a focal FDG uptake and a high SUV, have a high risk of thyroid malignancy. Further diagnostic work-up is needed in these cases.