Thyroid incidentalomas in FDG-PET/CT: prevalence and clinical impact

To evaluate the prevalence of thyroid FDG-PET/CT incidentalomas and the risk of malignancy in focal findings. A retrospective study of 3,062 PET scans was performed between 05/2006 and 09/2009. Prevalence of thyroid incidentalomas, risk of malignancy and correlation between standard uptake value (SUV) and cancer risk were analysed. The overall prevalence of thyroid incidentalomas was 2.4%. 71% showed a focal and 29% a diffuse uptake. In the focal uptake group, the diagnosis was clarified in 79% with cytology/histology. In 23.8% of the patients with a focal uptake, a malignant lesion was found. Diffuse uptake was predominantly associated with autoimmune thyroiditis. There was no statistically significant difference in the SUV_max between benign and malignant focal lesions (p?=?0.0982). Patients with incidental focal uptake in the thyroid during FDG-PET/CT bear a considerable risk of malignancy and should undergo cytologic clarification of the diagnosis.     

FDG-PET prediction of head and neck squamous cell cancer outcomes

OBJECTIVE: To confirm that high pretreatment uptake of 2-deoxy-2[(18)F]fluoro-d-glucose (FDG) detected by positron emission tomography (PET) measured at the primary head and neck squamous cell carcinoma (HNSCC) and at metastatic nodal disease predicts poor outcomes for HNSCC. DESIGN AND PATIENTS: We enrolled 63 consecutive patients with a histological diagnosis of HNSCC (including tumors of the oral cavity, oropharynx, larynx, and hypopharynx) from September 2000 through June 2003, into a prospective institutional imaging trial. Fifty-four patients (86%) underwent a baseline FDG-PET scan before curative treatment and were eligible for analysis. RESULTS: A primary tumor standardized uptake value (SUV) of greater than 9.0 predicted inferior local recurrence-free survival (P = .02) and disease-free survival (P = .03). Nodal SUV dichotomized according to the cohort median of 6.1 did not predict for either disease outcome (P = .71 and P = .98, respectively). On proportional hazards analysis, local recurrence and disease event hazard ratios for a primary tumor SUV of 9.0 or greater remained significant or at borderline significance when adjusted for nodal SUV or other clinical covariates. CONCLUSIONS: Our findings support an association between baseline primary tumor FDG SUV and HNSCC outcomes. In contrast, nodal FDG SUV was not predictive. Primary tumor FDG SUV is a promising prognostic factor and may establish the need for intensified locoregional therapy in individual patients. Multi-institutional imaging trials and further characterization of the biology responsible for elevated FDG uptake in HNSCC will be necessary to confirm the prognostic utility of FDG-labeled PET.     

Mcm-2 and Ki-67 have limited potential in preoperative diagnosis of thyroid malignancy

OBJECTIVES: Minichromosome maintenance protein 2 (Mcm-2) is essential for DNA replication and serves as a useful biomarker of cell-cycle state in human tissue samples. Ki-67 is an established proliferation marker. Because Mcm-2 expression has not previously been assessed in thyroid tissue, the aim of this study was to assess the expression of both proteins in a range of thyroid lesions to determine their potential value as preoperative markers of thyroid malignancy. METHODS: Mcm-2 and Ki-67 protein expression were assessed by immunohistochemistry in formalin-fixed, paraffin-embedded thyroid tissues from 128 patients with histologic diagnoses of papillary carcinoma (n = 38), follicular carcinoma (n = 22), follicular adenoma (n = 33), and dominant nodules of multinodular goitre (n = 35). RESULTS: Mcm-2 and Ki-67-labeling indices (LIs) were both higher in follicular and papillary carcinomas than in follicular adenomas or dominant nodules. The Ki-67 LI discriminated better between follicular carcinomas and follicular adenomas (P < .0001) than Mcm-2 (P = .0273). However, the Mcm-2 and Ki-67 LIs overlapped widely between the four histologic groups, and the expression of these proteins was also noted to be heterogenous within these lesions. CONCLUSION: Neither Mcm-2 or Ki-67 can currently be reliably applied as preoperative markers to distinguish benign from malignant thyroid lesions.     

Frozen section in a cytological diagnosis of thyroid follicular neoplasm

OBJECTIVE/HYPOTHESIS: Fine-needle aspiration biopsy is the most accurate diagnostic test for thyroid nodules, its only limitation being the diagnosis of follicular neoplasm that does not distinguish between benign and malignant follicular lesions. STUDY DESIGN: To determine the utility of intraoperative frozen-section analysis in cases of a cytological diagnosis of follicular neoplasm, a retrospective review of 66 patients with a solitary thyroid nodule and follicular neoplasm who underwent thyroid surgery was carried out. METHODS: Fine-needle aspiration was classified following the Papanicolaou Society of Cytopathology Classification, and frozen section was defined as malignant or "deferred." If a malignant diagnosis was made by frozen-section analysis, a total thyroidectomy was carried out. The extension of thyroid surgery in the deferred cases was based on the definitive histological diagnosis. RESULTS: Sixty-four cases were classified as deferred, and two as suspect for malignancy. Among the 64 deferred cases, 15 were malignant in the final pathological findings, and 49 were benign. The two suspect cases were papillary carcinoma. Frozen-section analysis classified 2 of 17 (11.7%) cases as follicular variant of papillary carcinoma that could not be diagnosed by cytological study. However, these two cases had a strong clinical evidence of malignancy. CONCLUSION: The routine use of frozen-section analysis is useless in cases of cytological diagnosis of follicular neoplasm on fine-needle aspiration biopsy, because of the low probability of achieving the diagnosis of follicular carcinoma and the inability to provide additional information apart from the clinical and the cytological data.     

The cytological and clinical value of the thyroid "follicular lesion"

BACKGROUND: The main limitation of fine-needle aspiration (FNA) is its limited distinction between neoplastic and benign lesions. We summarize our experience with thyroid nodules that were defined as follicular lesions by comparing the clinical and cytological features of the thyroid follicular lesions that were examined histologically to define the most reliable criteria of malignancy. METHODS: The medical records of all patients who underwent thyroid aspiration at Rabin Medical Center from 1999 to 2000 were reviewed for a diagnosis of follicular lesion that warranted surgery (N = 58). The cytology and pathology reports of the patients who met these criteria were reviewed and compared with the original reports. RESULTS: The incidence of malignancy in follicular lesions of the thyroid is about 26%. There was a significant correlation between a histologic diagnosis of carcinoma and the cytologic findings of nuclear grooves (P =.041), solid arrangement (P =.019), hypercellularity (P =.01), and hypercellularity to colloid amount ratio (P =.016). Nodular size was predictive of malignancy. No correlation was found between patient age or gender and tendency toward malignancy. CONCLUSIONS: The combination of cytological characteristics and the size of the nodule aspirate are predictive values of malignancy. We believe that every follicular lesion should be excised to obtain a definitive histological diagnosis based on capsular or vascular invasion.     

A single-center multidisciplinary study analyzing thyroid nodule risk stratification by comparing the thyroid imaging reporting and data system (TI-RADS) and American thyroid association (ATA) risk of malignancy for thyroid nodules

ObjectivesThe thyroid imaging reporting and data system (TI-RADS) and 2015 American Thyroid Association (ATA) guidelines are two well-known risk stratification systems for classifying thyroid nodules based on cancer risk. This study aims to evaluate the diagnostic efficacy of these two systems in predicting malignancy in patients undergoing thyroid surgery.MethodsWe studied data on 120 individuals who were scheduled to undergo surgery for benign or malignant nodular diseases of the thyroid gland between October 2017 and October 2019. The TI-RADS category and ultrasound pattern based on ATA guidelines were assigned to dominant thyroid nodule categories by two experienced radiologists blinded to patients’ previous thyroid ultrasonography and fine-needle aspiration biopsy results. A pathologist with experience in thyroid diseases blinded to patients’ sonographic and clinical data reviewed the thyroidectomy specimens.ResultsA total of 120 patients, 88 women and 32 men, were included in our study. Final histopathological results were as follows: 50% (n=60) papillary thyroid carcinoma, 36.6% (n=44) benign nodular thyroid diseases, 4.1% (n=5) follicular adenoma, 2.5% (n=3) hurtle cell adenoma, 1.7% (n=2) follicular thyroid carcinoma, 1.7% (n=2) medullary thyroid carcinoma, 1.7% (n=2) hurtle cell carcinoma, and 1.7% (n=2) follicular tumor of uncertain malignancy potential. The sensitivity, specificity, positive predictive value, and negative predictive value for TI-RADS were 80%, 56%, 72%, and 67%, respectively, and that for ATA were 80%, 64%, 76%, and 69%, respectively.ConclusionThe TI-RADS and ATA showed similar rates of sensitivity, specificity, NPV, and PPV. Our observed risk of malignancy was higher than expected for the ACR TI-RADS 3–5 categories and the very low, low, and intermediate suspicion risk strata in the ATA guidelines. We found no difference between observed and expected malignancy risk for the ACR TI-RADS 2’s and ATA's high suspicion categories.     

Is there a role for fluorodeoxyglucose positron emission tomography/computed tomography in cytologically indeterminate thyroid nodules?

OBJECTIVE: The aim of this study was to determine the accuracy of the fluorine 18 ((18)F)-labeled fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scan in the evaluation of thyroid nodules in which the cytopathology of fine-needle aspiration (FNA) biopsies are classified as "indeterminate," ie, either follicular or Hürthle cell lesion. METHODS: At an academic medical center, we conducted a prospective pilot study of 15 patients with thyroid nodules in whom adequate FNA was diagnosed as indeterminate. All patients underwent a whole-body FDG-PET/CT scan followed by thyroidectomy. Preoperative FDG-PET/CT results and the histopathology of the surgical specimen were compared and statistically analyzed. RESULTS: The FNA demonstrated follicular cells in 11 (73%) patients, Hürthle cells in 3 (20%) patients, and both types of cells in 1 (7%) patient. The histopathology of the surgical specimen revealed thyroid cancer in 7 (47%) patients. The FDG-PET/CT scan was positive in 8 patients; 4 (50%) patients were found to have cancer. The FDG-PET/CT scan was negative in 7 patients. Four of these patients had benign lesions and 3 had thyroid carcinoma. Thus, 4 (27%) patients had false-positive FDG-PET/CT scans and 3 (20%) patients had false-negative studies. The sensitivity of FDG-PET/CT to detect a malignant focus was 57% with a specificity of 50%. The positive predictive value was 50% and the negative predictive value was 57%. CONCLUSIONS: In this pilot study of patients with cytologically indeterminate thyroid nodules, FDG-PET/CT was not a predictable indicator of benign or malignant disease. Although a larger series may elucidate a role for FDG-PET/CT, the relatively low predictability shown in this study should caution clinicians about using FDG-PET/CT to consider foregoing thyroidectomy for cytologically indeterminate nodules.     

The role of positron emission tomography and positron emission tomography/computed tomography in thyroid tumours: an overview

Positron emission tomography (PET) and PET/computed tomography (PET/CT) with different tracers have been increasingly used in patients with thyroid tumours. The aim of this article is to perform an overview based on literature data about the usefulness of PET imaging in this setting. The role of Fluorine-18-Fluorodeoxyglucose (FDG) PET and PET/CT in differentiated thyroid carcinoma (DTC) is well established, particularly in patients presenting with elevated serum thyroglobulin levels and negative radioiodine whole-body scan. Iodine-124 PET and PET/CT may serve a role in staging DTC and obtaining lesional dosimetry for a better and more rationale planning of treatment with Iodine-131. FDG-PET and PET/CT are useful in the post-thyroidectomy staging of high-risk patients with less differentiated histological subtypes. PET and PET/CT with different tracers seem to be useful methods in localizing the source of elevated calcitonin levels in patients with recurrent medullary thyroid carcinoma. Incorporation of FDG-PET or PET/CT into the initial workup of patients with indeterminate thyroid nodules at fine needle aspiration biopsy deserves further investigation. FDG-PET report should suggest further evaluation when focal thyroid incidentalomas are described because these findings are associated with a significant risk of cancer.     

Evaluation of the impact of addition of PET to CT and MR scanning in the staging of patients with head and neck carcinomas

The addition of whole body positron emission tomography (PET) to the investigation of patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC) was assessed over a 6-month period. Staging investigations included laryngoscopy, oesophagoscopy, CXR, CT and MRI. In addition, all patients had an extended-field (whole body) FDG-PET scan and were restaged. Standardised Uptake Values (SUV) were used to measure FDG uptake. SUV levels above 5 were considered indicative of the presence of tumour, values below 3 indicative of benign aetiology and values equal to and between 3 and 5 were considered equivocal. Forty-eight consecutive patients with biopsy proven HNSCC were included for study. Three patients presenting with neck disease had unknown primary tumours. Of the remaining 45 patients, CT scan correctly identified 40 of the primary tumours (89%). MRI and PET both identified 41 primary tumours (91%). Thirty-two patients underwent neck dissection. Of these patients 12 had pathologically N0 necks and 20 had positive nodal disease. CT scan and MRI each correctly staged pN0 necks in 10 of 12 patients (83%) whereas PET alone had a lower true negative rate of 8 out of 12 patients (67%). PET correctly staged the N+ necks in 14/20 patients (70%) versus 12/20 (60%) for MRI, and 8/20 (40%) for CT alone. All four patients who were judged to have distant metastases by PET had these metastases deemed negative by other investigation. None of the three imaging modalities was able to identify the tumour site in the three patients with unknown primaries. In conclusion, although PET has got a higher sensitivity in detecting nodal disease, it has only slightly improved the classification of N+ necks. The findings of this study cast doubt on the merit of routine addition of PET to the current investigative protocols for HNSCC patients.Presented at the Irish Otolaryngology Society annual meeting, Oct 2003     

FDG-PET scan in local follow-up of irradiated head and neck squamous cell carcinomas

We performed a prospective study to assess the value of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in the prediction of local control in irradiated head and neck squamous cell carcinomas (HNSCCs). Forty-two patients with irradiated HNSCCs underwent 49 FDG-PET scans between 3 and 6 months after the end of radiotherapy. The mean follow-up time after the first FDG-PET scan was 17 months. The result of the FDG-PET scan was true-positive in 6 patients, false-positive in 7 patients, and true-negative in 29 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET scanning were 100%, 81%, 46%, and 100%, respectively. We conclude that FDG-PET scanning is useful for prediction of therapy outcome in irradiated HNSCCs. No biopsy is needed for at least 1 year if an FDG-PET scan is negative. If the scan is positive and the biopsy is negative, decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.     

Management of thyroid carcinoma-an experience in Bangladesh

All patients (n=154) of thyroid malignancy admitted in the Otoluryngology Department of Bangabandhu Sheikh Mujib Medical University (former IPGMR) between 1986 and 2000 were retrospectively analyzed to find out the extent and result of surgery used for thyroid carcinoma. The other objectives were to find out the incidence of differentiated thyroid carcinoma among the thyroid malignancy and also to find out the age, sex and clinical presentation of papillary and follicular carcinoma. Among all the thyroid malignancy (n-154), Differentiated Thyroid Carcinoma (DTC) was seen in 130 (84.41%) cases, where as papillary carcinoma occurred in 98(63.64%), and follicular carcinoma in 32(20.77%)cases. On the basis of risk factors, the DTC were designated as low and high risk. The year-wise incidence of DTC revealed increasing trend from 1986 (3 cases) to 2000 (23 cases). Among the 98 papillary thyroid carcinoma highest number of cases (35.71%) were seen in 31-40 year age group. The male to female ratio was 1: 1.64. In follicular carcinoma, highest number (35.25%) of cases were also seen in 31-40 year age group. The male to female ratio was 1:1.66. The commonest presentation in papillary carcinoma was thyroid swelling (96.93%). The other presentations were occult thyroid (3.06%), Cervical lymph node metastasis (38.77%) and distant metastasis (2.04%). In Follicular carcinoma, the presentations were thyroid swelling (100%), Cervical lymph node metastasis (6.25%) and Distant metastasis (21.87%). In this series, low risk DTC were treated by Lobectomy & Isthmusectomy plus Thyroxin. In low risk group the rate of recurrence was 6.89% and the mortality was nil in five years follow-up. Except two inoperable cases, all high risk patients were managed by Total thyroidectomy (with or without neck dissection, plus removal of metastatic lesion when required) with Radioiodine ablation plus Thyroxin. . The rate of recurrence was 7.81% and mortality was 1.56% in high risk group in similar period of time. Vocal cord palsy were noted in 5 (3.84%) unilateral, and inane (0.76%) bilateral cases. Hypoparathyroidism was found in 4.61%.     

甲状腺细胞病理学Bethesda报告系统的临床应用:肿瘤专科医院5729例样本的回顾性分析

目的分析肿瘤专科医院甲状腺细胞病理学Bethesda报告系统的数据特点,评价甲状腺细针穿刺(fine needle aspiration,FNA)的诊断能力。方法回顾性分析2017年1月至2018年12月中国医学科学院肿瘤医院行甲状腺FNA检查的5729个组织的临床资料,来自5011例患者,其中男1174例,女3837例,年龄7~88岁,中位年龄45岁。以术后组织病理学结果为金标准,分析Bethesda分级系统各诊断级别的恶性风险和甲状腺FNA的诊断能力。结果5729个细胞学诊断包括:无法诊断或标本不满意(nondiagnostic or unsatisfactory,ND/UNS)456个(8.0%),良性(benign)1055个(18.4%),意义不明确的非典型病变或意义不明确的滤泡性病变(atypia of undetermined significance or follicular lesion of undetermined significance,AUS/FLUS)409个(7.1%),滤泡性肿瘤或可疑滤泡性肿瘤(follicular neoplasm or suspicious for a follicular neoplasm,FN/SFN)80个(1.4%),可疑恶性(suspicious for malignancy,SUS)982个(17.1%),恶性(malignant)2747个(47.9%)。3239个有术后病理结果,其中恶性者3109个(95.99%)。各诊断级别的恶性风险分别为:ND/UNS 75.00%,良性40.91%,AUS/FLUS 77.67%,FN/SFN 41.67%,SUS 96.86%,恶性99.96%。FNA诊断的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为98.8%、60.5%、97.7%、98.9%和59.1%。结论肿瘤专科医院甲状腺Bethesda报告系统的数据具有恶性诊断占比高和各诊断级别恶性风险高的特点。FNA诊断准确性高,且有较高的阳性预测值。     

甲状腺结节细针穿刺细胞学检查评估

目的 探讨甲状腺细针穿刺细胞学(fine-needle aspiration,FNA)检查的临床价值.方法 回顾性分析中国医学科学院肿瘤医院2005年10月至2011年1月行甲状腺细针穿刺的474例连续病例资料.B超引导下穿刺218例(46.0％),触诊穿刺256例(54.0％).细胞学诊断结果分为六级:无法诊断、良性、不典型细胞、滤泡样肿瘤、可疑恶性及恶性.将其中157例手术患者术前细胞学诊断结果与术后组织病理学诊断结果进行比较.结果 157例手术治疗患者中91例为恶性,术前FNA诊断为无法诊断2/7、良性16.7％ (9/54)、不典型细胞3/9、滤泡样肿瘤1/3、可疑恶性83.3％( 35/42)、恶性97.6％ (41/42).甲状腺细针穿刺鉴别甲状腺结节良恶性的敏感度为85.4％,特异度为86.9％.阳性预测值90.5％.结论甲状腺细针穿刺细胞学诊断能够为甲状腺疾病提供较为准确的术前诊断.六级诊断方法有助于临床治疗方案的选择.     

Variables predicting distant metastases in thyroid cancer

OBJECTIVES: Distant metastases from thyroid cancer are uncommon and have a variable prognosis. We present a series of patients with distant metastases to determine which patients are at risk of developing distant disease and to examine the significant prognostic variables. STUDY DESIGN: Retrospective chart review of 30 patients with distant metastases compared with 633 controls from the Mount Sinai Thyroid Cancer Database and literature review. METHODS: The prevalence of distant metastases was 4.5%, and median follow-up of survivors was 12.7 years. Histologic type was Hurthle cell carcinoma in 3, follicular in 3, papillary in 19, and 5 patients had focal anaplasia either in the primary site or regional metastases. Predictors for distant metastases, locoregional control, and survival were analyzed. RESULTS: Cumulative survival for patients with distant metastases was 49.5% at 10 years and 12.9% at 20 years. Site of metastases was lung in 26, bone in 11 and brain in 1 patient, with 8 patients having multiple sites. The median time to diagnosis of distant metastases was 3 months. Variables that predicted for development of distant disease were male sex, age, size, extrathyroidal extension, regional metastases, and elevated thyroglobulin. Survival in patients without distant disease was significantly better than those with distant metastases (P < .001). Variables that predicted poor outcome in patients with distant metastases on analysis were age greater than 45 years (P = .003) and histologic type of thyroid cancer (P = .009). CONCLUSION: Although patients with thyroid cancer and distant metastases may live prolonged periods with disease, it does significantly impact on patient survival. Age remains an important variable in both predicting for development of distant metastases and also influences long-term survival in patients with existing distant metastases.     

Follicular variant of papillary carcinoma: the diagnostic limitations of preoperative fine-needle aspiration and intraoperative frozen section evaluation

OBJECTIVE: Fine-needle aspiration (FNA) and frozen section (FS) have been widely reported in the literature as having high sensitivity in the diagnosis of papillary carcinoma. With the increased recognition of the follicular variant of papillary thyroid carcinoma (FVPTC), several reports have pointed out the difficulty in diagnosing this variant of papillary carcinoma owing to its overlapping cytomorphological features with benign and malignant follicular lesions. We undertook this study to determine the sensitivity of FNA and FS in the diagnosis of FVPTC. METHODS: Retrospective review of patients who underwent thyroidectomy from June 1994 to June 1999. Of the 63 patients found with a final pathological diagnosis of papillary thyroid carcinoma, only 47 had an adequate FNA and FS and were included in the study. These patients were divided into two groups, the usual type (n = 23) and the follicular variant (n = 24) of papillary carcinoma. Sensitivities of FNA and FS for these two groups of papillary carcinoma were then determined. RESULTS: The sensitivity of the FNA was 25% and of the FS was 29% for the follicular variant of papillary thyroid carcinoma. This is in contrast to the sensitivity of FNA and FS for the usual papillary carcinoma, which were 74% and 87%, respectively. CONCLUSION: FNA and FS have low sensitivity in the diagnosis of the FVPTC. High degree of suspicion may increase the accuracy in the diagnosis of this variant of papillary carcinoma before or during surgery. However, the thyroid surgeon needs to realize that, like follicular carcinoma, FVPTC is often diagnosed only on final pathological examination.     

Papillary thyroid carcinoma metastasis to parapharyngeal lymph nodes: interest of the PET scan

Thyroid cancer rarely metastasizes to the parapharyngeal space. A inconsistent lymphatic drainage pathway is involved, as described by Rouvière. OBJECTIVES: To demonstrate the interest of [18 F]-FDG PET in early diagnosis of metastasis and in the follow up of the patient. MATERIAL AND METHOD: 40 y.o. male with papillary carcinoma who had a secondary parapharyngeal metastasis. The diagnosis of recurrence was difficult, as the plasmatic thyglobulin was low, and the iodine scan was not informative. In this case, [18 F]-FDG PET-CT was informative (clear parapharyngeal fixation) and led to the diagnosis of recurrence. CONCLUSION: It appears that 18F FDG PET has a good diagnostic value and that its sensitivity is better than CT scan and MRI. Some authors recommend the use of [18 F]-FDG PET and scintigraphy with Iodine 131 to screen patients with thyroid cancer recurrences.     

Incidence of diffuse FDG uptake in the thyroid of patients with hypothyroidism

Positron emission tomography (PET) positive lesions are common in the thyroid. The uptake can be focal or diffuse. Diffuse thyroid uptake is thought to be indicative of autoimmune thyroiditis and not for lesions of malignant potential. Hashimoto’s thyroiditis as a cause for diffusely positive thyroid glands has been demonstrated. We determine the incidence of diffuse thyroid PET positivity in hypothyroid patients, presumed to have Hashimoto’s thyroiditis. The study design was retrospective database and electronic medical record review. The study setting includes tertiary care and academic health sciences center. The subjects were patients at our medical center who underwent positron emission tomography. Hypothyroid patients were identified who had total body PET imaging performed for any reason. Patients were excluded if they were not taking levothyroxine, had a history of neck surgery, neck irradiation, Graves’ disease, taking lithium, thalidomide, amiodarone or interleukin. Patients remaining after the application of these exclusion criteria were presumed to be hypothyroid from Hashimoto’s thyroiditis. Only 9.5% of PET scans of hypothyroid patients display diffuse thyroid activity. Only a small minority of presumed Hashimoto’s thyroiditis patients will display diffuse thyroid activity after PET imaging. The etiology of this effect is unknown. Diffuse thyroid activity rarely requires surgical intervention. Level of evidence: IV.     

Relationship between 18FDG-PET and different types of sinonasal malignancies

Conclusion: The sensitivity and specificity of a ¹⁸FDG-PET scan may be different according to the histology. The SUV_max and SUV ratio may reflect the tumor’s aggressive behavior.

Objectives: To describe the characteristics of PET/CT scans, including the maximum standard uptake values (SUV_max), at initial diagnosis according to six main types of sinonasal malignancies: sinonasal adenocarcinoma (SNAC), sinonasal undifferentiated carcinoma (SNUC), adenoid cystic carcinoma (ACC), sinonasal malignant melanoma (SMM), olfactory neuroblastoma (ONB), and sinonasal neuroendocrine carcinoma (SNEC).

Methods: A chart review of 50 patients who were diagnosed and treated for six sinonasal malignancy types over a period of 6 years was conducted. Any ¹⁸F-FDG PET/CT scans for each patient were searched using the hospital’s intranet. The SUV_max of the primary sinonasal site was recorded. The liver SUVs were utilized as reference SUVs. The SUV ratio was defined as the ratio of the SUV_max of the primary tumor and the SUV_liver.

Results: The most common malignancy was SNAC (32%), followed by SNUC (24%), ONB (14%), ACC (10%), SMM (10%), and SNEC (10%). The SUV_max and SUV ratio values were significantly different between tumor types (p?=?0.002 and 0.012, respectively). SNUC had the highest mean SUV_max (14.2), followed by SNAC (9.9). A similar mean SUV_max was observed for SMM, ONB, and ACC (～ 7.0). SNEC up-takes the least ¹⁸FDG among these six tumor types (mean SUV_max?=?4.7).     

Role of ultrasonography in patients with cytologically follicular thyroid tumor

Objective

The purpose of this study is to evaluate the role of ultrasonography (US) in the management of thyroid nodules when the cytology is indeterminate as follicular tumor on fine needle aspiration biopsy (FNAB).

Methods

In 2006, 6586 patients with thyroid nodules, which were detected on US underwent FNAB in our department. Of these patients, we extracted 438 patients (6.7%) whose nodules were cytologically diagnosed as indeterminate. Of them, 227 patients were diagnosed as follicular tumor were enrolled in this study. Surgery was performed according to our criteria for surgical indication. We compared the results of clinical findings including US classification and final histopathological diagnosis.

Results

One hundred thirty-seven of 227 underwent surgical treatment. Thirty-three (24%) were diagnosed as malignancy pathologically. Large nodule or high serum thyroglobulin level were not associated with an increased risk of malignancy. Ultrasonographic evaluation as malignancy was directly linked to pathological diagnosis as thyroid carcinoma (p < 0.0001).

Conclusion

US plays a crucial role in deciding whether surgical treatment is necessary for cytologically indeterminate thyroid nodules as follicular tumor.     

Clinical review of thyroid malignant tumor

We reviewed the files of 120 patients with thyroid malignant tumor treated in our department between July 1971 and December 1996. Clinical features, pathological diagnosis, radiographic findings, treatment and prognosis were studied. The number of patients treated gradually increased over time in both the otorhinolaryngology and surgery departments. Papillary carcinoma (n = 101) was the most common pathology, followed by follicular carcinoma (n = 16). Both 5- and 10-year survival rates were 92.7% for the entire group, 93.8% for cases of follicular carcinoma and 92.1% for cases of papillary carcinoma. Although thyroid tumor is undoubtedly one of the malignant head and neck tumors associated with an excellent prognosis, some patients remain resistant to cure in the long term. Some tumors are highly malignant and are difficult to control. The management of these patients is an important subject of future research.