Hürthle cell neoplasms of the thyroid: are there factors predictive of malignancy?

Unraveling the Enigma: A Five-Year Comprehensive Analysis of Hurthle Cell Tumors in South India's Tertiary Care Center

BACKGROUND

Hurthle cell tumors of the thyroid gland constitute a rare and enigmatic group of neoplasms, characterized by the presence of Hurthle cells exhibiting abundant eosinophilic cytoplasm and numerous mitochondria. Despite their low incidence, they pose diagnostic challenges and display diverse clinical outcomes. This study aims to provide a comprehensive analysis of the clinicopathological profile of Hurthle cell tumors within a tertiary care center in South India.

METHODS

Through a retrospective approach, we analyzed cases of Hurthle cell tumors diagnosed and treated at a tertiary care center over a five-year period. Clinical, radiological, and histopathological data were meticulously collected and scrutinized. The study focused on examining demographic details, presenting symptoms, imaging features, cytological findings, surgical management, and postoperative outcomes of the patients.

RESULTS

A total of 32 cases of Hurthle cell tumors were identified during the study period. The majority of patients were female (84%), with a mean age of 49.6 years for Hurthle cell carcinoma. Thyroid enlargement and neck mass were the most common presenting complaints. Fine-needle aspiration cytology showed characteristic features suggestive of Hurthle cell tumors in 33% of cases. Total thyroidectomy remains the mainstay surgical approach. Histopathological evaluation confirmed 62.5% of cases as benign adenomas and 37.5% as malignant carcinomas. Among malignant cases, 67% showed capsular invasion and 33% demonstrated vascular invasion. Of the patients, 33.3% received adjuvant radiotherapy. The overall survival rate was 100%. In our study, we found that thyroid nodules larger than 3 cm demonstrated a higher propensity for Hurthle cell carcinoma.

CONCLUSION

Our findings support the multidisciplinary approach in managing Hurthle cell tumors, with a focus on tailored treatment plans for each patient based on individual characteristics. By recognizing the female predominance, assessing nodule size, and employing a combination of thyroidectomy and ablative therapy, clinicians can optimize patient care and contribute to better long-term prognosis and quality of life for those affected by Hurthle cell tumors. Continued research and collaborative efforts are necessary to advance our understanding and refine treatment strategies, paving the way for improved outcomes and enhanced patient management in the future.

Somatostatin Receptor Type 2 and Thyroid-Stimulating Hormone Receptor Expression in Oncocytic Thyroid Neoplasms: Implications for Prognosis and Treatment

Somatostatin receptor type 2 (SSTR2) and thyroid-stimulating hormone receptor (TSHR) display variable expression in primary thyroid tumors and have been implicated as theranostic targets. This study was designed to explore the differential expression of SSTR2 and TSHR in oncocytic (Hurthle cell) carcinoma (OC) vs oncocytic adenoma (OA). We performed a retrospective review for oncocytic neoplasms treated at our institution from 2012 to 2019. Formalin-fixed paraffin-embedded tissue blocks were used for tissue microarray construction. Tissue microarray blocks were cut into 5-μm sections and stained with anti-SSTR2 and anti-TSHR antibodies. Immunostains were analyzed by 3 independent pathologists. χ2 and logistic regression analysis were used to analyze clinical and pathologic variables. Sixty-seven specimens were analyzed with 15 OA and 52 OC. The mean age was 57 years, 61.2% were women, and 70% were White. SSTR2 positivity was noted in 2 OA (13%) and 15 OC (28%; 10 primary, 4 recurrent, and 1 metastatic) (P = .22). TSHR positivity was noted in 11 OA (73%) and 32 OC (62%; 31 primary and 1 metastatic) (P = .40). Those who presented with or developed clinical recurrence/metastasis were more likely to be SSTR2-positive (50% vs 21%; P = .04) and TSHR-negative (64.3% vs 28.9%; P = .02) than primary OC patients. Widely invasive OC was more likely to be SSTR2-positive compared to all other OC subtypes (minimally invasive and angioinvasive) (P = .003). For all patients with OC, TSHR positivity was inversely correlated with SSTR2 positivity (odds ratio, 0.12; CI, 0.03-0.43; P = .006). This relationship was not seen in the patients with OA (odds ratio, 0.30; CI, 0.01-9.14; P = .440). Our results show that recurrent/metastatic OC was more likely to be SSTR2-positive and TSHR-negative than primary OC. Patients with OC displayed a significant inverse relationship between SSTR2 and TSHR expression that was not seen in patients with OA. This may be a key relationship that can be used to prognosticate and treat OCs.

Thyroid Hürthle Cell Carcinoma: Clinical, Pathological, and Molecular Features

Simple Summary

Hürthle cell carcinoma (HCC) represents 3–4% of thyroid carcinoma cases. It is characterized by its large, granular and eosinophilic cytoplasm, due to an excessive number of mitochondria. Hürthle cells can be identified only after fine needle aspiration cytology biopsy or by histological diagnosis after the surgical operation. Published studies on HCC indicate its putative high aggressiveness. In this article, current knowledge of HCC focusing on clinical features, cytopathological features, genetic changes, as well as pitfalls in diagnosis are reviewed in order to improve clinical management.

Abstract

Hürthle cell carcinoma (HCC) represents 3–4% of thyroid carcinoma cases. It is considered to be more aggressive than non-oncocytic thyroid carcinomas. However, due to its rarity, the pathological characteristics and biological behavior of HCC remain to be elucidated. The Hürthle cell is characterized cytologically as a large cell with abundant eosinophilic, granular cytoplasm, and a large hyperchromatic nucleus with a prominent nucleolus. Cytoplasmic granularity is due to the presence of numerous mitochondria. These mitochondria display packed stacking cristae and are arranged in the center. HCC is more often observed in females in their 50–60s. Preoperative diagnosis is challenging, but indicators of malignancy are male, older age, tumor size > 4 cm, a solid nodule with an irregular border, or the presence of psammoma calcifications according to ultrasound. Thyroid lobectomy alone is sufficient treatment for small, unifocal, intrathyroidal carcinomas, or clinically detectable cervical nodal metastases, but total thyroidectomy is recommended for tumors larger than 4 cm. The effectiveness of radioactive iodine is still debated. Molecular changes involve cellular signaling pathways and mitochondria-related DNA. Current knowledge of Hürthle cell carcinoma, including clinical, pathological, and molecular features, with the aim of improving clinical management, is reviewed.

[Analysis of diagnosis and treatment of 100 patients with Hürthle cell adenoma]

OBJECTIVE

To summarize and analyze the clinical data and prognosis of the patients with Hürthle cell tumor (HCT) in order to raise the clinicians' awareness of the disease.

METHODS

The clinical data on patients with histopathologically proven HCT, without other thyroid carcinomas, were collected retrospectively in Peking University First Hospital from January 2001 to February 2017. All the patients underwent surgery due to thyroid nodules. The follow-up information was also collected.

RESULTS

A total of 100 patients were enrolled in the current study. All of them were diagnosed with Hürthle cell adenoma (HCA). There were 77 females and 23 males, with the male-to-female ratio of 1 : 3.3. The average age of these patients was (52±14) years at the time of operation. Fifty-one patients were found their thyroid nodules accidentally by ultrasonography during their health check-ups. 69.4% of the 49 symptomatic patients presented with painless cervical nodules. 83.0% HCA patients were combined with multinodular goiters (MNGs). 88.4% (76/86) patients were euthyroid and 53.8% (21/39) had increasing thyroglobulin levels. The mean longest diameter of HCAs was (3.2±1.5) cm (range: 0.9-7.3 cm) on ultrasonography. There were a series of sonographic features of HCA, such as larger, solidity, hypoecho, a smooth outline, intranodular vascularization, perinodular vascularization, absence of calcification in nodules and absence of enlarged cervical lymph nodes. Compared with the histological diagnosis, the diagnostic accuracy by frozen section (FS) during operation was 97.4%. Twenty-nine patients were followed up with an average period of (49.2±22.1) months and none of them had local recurrence or cervical lymph node metastasis. Six patients accepted thyroid hormone replacement treatment and one had thyrotoxicosis due to over-dose.

CONCLUSION

HCA is more common in women. It is often found accidentally by ultrasonography during their health check-ups or presented with painless cervical nodules. It is combined with MNG frequently. HCA exhibits numerous sonographic features but not unique. FS during operation is a reliable method to identify HCA with high diagnostic accuracy. Patients with thyroid hormone administration should be monitored for thyroid function after thyroid surgery.

Hurthle cell carcinoma in childhood: A retrospective analysis of five cases and review of pediatric literature

BACKGROUND

the available studies on Hurthle cell carcinoma (HCC) in pediatric age are scarce and based on isolated case reports. Aims of the present study were to review the available pediatric literature on HCC (2000-2019), to describe the cohort of children with this cancer histotype, and to estimate its relative prevalence in pediatric age.

PROCEDURE

We retrospectively reconstructed an HCC course in five patients < 19 years who were identified in our departments during the period 2000-2019, and we reviewed the available pediatric studies on this differentiated thyroid cancer (DTC) variant.

RESULTS

HCC occurred with a relative prevalence of 5.8% at a median chronological age of 12.5 years. None of HCC patients exhibited, at diagnosis, thyroid dysfunction, extensive lateral neck disease, or distant metastases, and all showed a persistent remission over time. Three patients showed, at diagnosis, antecedents of other diseases (Hashimoto's thyroiditis, neurofibromatosis type 1, and osteosarcoma).

CONCLUSIONS

(1) In childhood, the relative prevalence of HCC among different thyroid cancer histotypes is 5.8%, that is close to the one previously reported both in the general population and in other less numerous children's cohorts; (2) HCC may develop even early, at the age of 7; (3) in childhood, HCC does not seem to have a more aggressive behavior when compared with other DTC histotypes; (4) antecedents of other diseases are not infrequent in the history of children with HCC.

Clinical impact of follicular oncocytic (Hürthle cell) carcinoma in comparison with corresponding classical follicular thyroid carcinoma

PURPOSE

There are controversial debates if patients with Hürthle cell carcinoma, also known as oxyphilic or oncocytic cell follicular thyroid carcinoma, have a poorer outcome. In this study, we systematically evaluated the clinical outcome in a large patient cohort following thyroidectomy and initial I-131 radioactive iodine therapy (RIT).

METHODS

We retrospectively evaluated a total of 378 patients with diagnosed oncocytic follicular Hürthle cell carcinoma (OFTC) (N = 126) or with classical follicular thyroid carcinoma (FTC) (N = 252). Patients received thyroidectomy and complementary I-131 RIT. Clinical data regarding basic demographic characteristics, tumor grade, persistent disease and recurrence during follow-up, and disease-free, disease-specific, and overall survival were collected during follow-up of 6.9 years (interquartile range 3.7; 11.7 years). Univariate and multivariate analyses were used to identify factors associated with disease-related and overall survival.

RESULTS

Before and after matching for risk factors, recurrence was significantly more frequently diagnosed in OFTC patients during follow-up (17% vs. 8%; p value 0.037). Likewise, OFTC patients presented with a reduced mean disease-free survival of 17.9 years (95% CI 16.0-19.8) vs. 20.1 years (95% CI 19.0-21.1) in FTC patients (p value 0.027). Multivariate analysis revealed OFTC (HR 0.502; 95% CI 0.309-0.816) as the only independent prognostic factor for disease-free survival. Distant metastases of OFTC patients were significantly less iodine-avid (p value 0.014). Mean disease-specific and overall survival did not differ significantly (p value 0.671 and 0.687) during follow-up of median 6.9 years (3.7; 11.7 years).

CONCLUSIONS

Our study suggests that recurrence is more often seen in OFTC patients. OFTC patients have a poorer prognosis for disease-free survival. Thus, OFTC and FTC behave differently and should be categorized separately. However, patients suffering from OFTC present with the same overall and disease-specific survival at the end of follow-up indifferent to FTC patients after initial RIT.

Is thyroid nodule volume predictive for malignancy?

OBJECTIVE

We aimed to determine the roles of preoperative thyroid nodule diameter and volume in the prediction of malignancy.

SUBJECTS AND METHODS

The medical records of patients who underwent thyroidectomy between January 2007 and December 2014 were reviewed. The nodule diameters were grouped as < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, and volume was grouped as > 5 cm3, 5-9.9 cm3 and > 10 cm3. ROC (Receiver Operating Characteristic) curve analysis was performed to find the optimal cutoff value of diameter and volume that can predict malignancy.

RESULTS

There were 5561 thyroid nodules in 2463 patients. Five hundred and forty (9.7%) nodules were < 1 cm, 2,413 (43.4%) were 1-1.9 cm, 1,600 (28.8%) were 2-3.9 cm and 1,008 (18.1%) were ≥ 4 cm. Malignancy rates were 25.6%,10.6%, 9.7% and 8.5% in nodules < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, respectively. When classified according to volume, 3,664 (65.9%) nodules were < 5 cm3, 594 (10.7%) were 5-9.9 cm3 and 1,303 (23.4%) were ≥ 10 cm3. The malignancy rates were 12.7%, 11.4% and 7.8% for the nodules < 5 cm3, 5-9.9 cm3 and ≥ 10 cm3, respectively (p < 0.001). In ROC curve analysis, an optimal cutoff value for diameter or volume that can predict malignancy in all thyroid nodules or nodules ≥ 4 cm could not be determined.

CONCLUSION

In this surgical series, malignancy risk did not increase with increasing nodule diameter or volume. Although the volume of malignant nodules ≥ 4 cm was higher than that of benign nodules ≥ 4 cm, there was no optimal cutoff value. The diameter or volume of the nodule cannot be used to predict malignancy or decide on surgical resection.

Ultrasonic diagnosis for thyroid Hürthle cell tumor

OBJECTIVE

This study aims to evaluate the diagnostic value of ultrasound in thyroid Hürthle cell tumors.

METHODS

A retrospective analysis was carried out on 27 patients with thyroid Hürthle cell tumors, in terms of the size, shape, boundary, echo, aspect ratio, cystic degeneration, calcification, peripheral halo sign and blood supply of the tumor, through surgical pathological validation. Then, these were compared with postoperative pathological results.

RESULTS

The maximum diameter of the thyroid Hürthle cell tumors is between 0.6 cm and 4.6 cm. It had an oval nodule with clear boundaries, an aspect ratio > 1, and peripheral low-echo halos. Furthermore, 29.6% of tumors have even low-echo nodules without cystic changes, 48.1% and 22.1% have even medium or medium-low mixed echo nodules, and 44.4% have cystic changes in varying degrees. One nodule appeared with "micro-calcification", but pathological results confirmed that it was local collagen. Color Doppler blood flow imaging revealed that 88.8% of the nodules were surrounded with blood flow, filled with rich blood inside, and only 12.2% of the nodules had a little blood inside.

CONCLUSION

Thyroid Hürthle cell tumors have nodules with even or uneven echoes on the background of the normal echoes of the thyroid, with an aspect ratio of > 1, clear boundaries and peripheral acoustic halos. Cystic changes, colloid crystallization and fibrosis can be seen inside in varying degrees. Ultrasonography has no significant value for the differential diagnosis of benign and malignant Hürthle cell tumors.

Size of thyroid carcinoma by histotype and variants: A population-based study in a mildly iodine-deficient area

BACKGROUND

Data relating the size of thyroid cancer with histological types and variants are scarce.

METHODS

All incident thyroid cancer diagnosed between 2003 and 2012 in a mildly iodine-deficient area were derived from a population-based tumor registry. Undifferentiated/anaplastic thyroid cancer and incidental cases were excluded. Major diameter of thyroid cancer, as assessed by pathological examination, was stratified in classes: ≤10 mm; 11-20 mm; 21-40 mm; and >40 mm. For each class, absolute and relative frequencies of histological types were calculated.

RESULTS

Tumors >20 mm were more frequent among follicular thyroid carcinoma (FTC) and Hürthle cell carcinoma than in other histotypes, with median size of 22.50 mm (95% confidence interval [CI] 16.71-28.29) and 25.00 mm (95% CI 17.04-32.96) in FTC and Hürthle cell carcinoma, respectively. Odds ratio for tumors >20 mm was significant for FTC and Hürthle cell carcinoma only (P < .0001).

CONCLUSION

Among the histotypes and variants of differentiated thyroid cancer, FTC and Hürthle cell carcinoma are characterized by the largest size.

A Unique Case of Bilateral Hürthle Cell Adenoma in an Adolescent

BACKGROUND

Hürthle cell (HC) neoplasms are rare among pediatric thyroid cancers. HC adenomas (HCA) are typically benign and localized unilaterally without recurrence, and they are thus treated by hemithyroidectomy. HC carcinomas (HCC) can be bilateral and are more aggressive, necessitating total thyroidectomy. Diagnosis relies upon surgical histopathology demonstrating invasion for classification as HCC or lack of invasion in HCA, since fine needle aspiration fails to differentiate between the two.

METHODS

We report a case of a 14-year-old adolescent female with bilateral HCA. She had an initial left hemithyroidectomy for a large nodule measuring 2 × 1.5 × 1.2 cm3 in the left lobe, while smaller subcentimeter nodules remained under surveillance in the right. One year later, a nodule in the right lobe doubled in size, necessitating a right hemithyroidectomy which also revealed HCA.

CONCLUSION

To our knowledge, this is the first reported case of bilateral HCA in pediatrics. It highlights the importance of close surveillance of persistent small nodules, even in patients with previously documented benign lesions such as HCA, which are typically thought to be unilateral and localized. Both HCA and HCC remain unpredictable in behavior, and treatment of HCA should be individualized.

Hürthle cell carcinoma: current perspectives

Hürthle cell carcinoma (HCC) can present either as a minimally invasive or as a widely invasive tumor. HCC generally has a more aggressive clinical behavior compared with the other differentiated thyroid cancers, and it is associated with a higher rate of distant metastases. Minimally invasive HCC demonstrates much less aggressive behavior; lesions <4 cm can be treated with thyroid lobectomy alone, and without radioactive iodine (RAI). HCC has been observed to be less iodine-avid compared with other differentiated thyroid cancers; however, recent data have demonstrated improved survival with RAI use in patients with HCC >2 cm and those with nodal and distant metastases. Patients with localized iodine-resistant disease who are not candidates for a wait-and-watch approach can be treated with localized therapies. Systemic therapy is reserved for patients with progressive, widely metastatic HCC.

Implications of oncocytic change in papillary thyroid cancer

OBJECTIVE

Although the presence of oncocytic change in less than 75% of a tumour is not considered to indicate oncocytic variants of papillary thyroid carcinoma (PTC), we frequently observe partial oncocytic change, especially in obese PTC patients. Thus, we sought to investigate the relationship between the presence of oncocytic change of PTC and its prognosis.

DESIGN, SETTING AND PARTICIPANTS

We retrospectively studied 142 patients with PTC who had undergone surgery between 2000 and 2005, and re-evaluated their PTC slides to record the proportion of oncocytic change in 10% increments from 0% to 100%.

MAJOR OUTCOME MEASURE

We analysed the relationship between the proportion of oncocytic change and clinicopathological prognostic factors.

RESULTS

Oncocytic change was found in 45·8% (65/142) of PTC patients. The proportion of patients with oncocytic change was higher in obese patients than in lean patients and showed a significant correlation with the BMI (r = 0·195, P = 0·020). The PTC patients with oncocytic change showed a higher recurrence rate than PTC patients without oncocytic change (30·8% vs 11·7%, respectively; P = 0·005). The presence of oncocytic change in PTC patients was associated with a shorter disease-free survival in a Kaplan-Meier analysis after a mean follow-up of 8·9 years.

CONCLUSION

The patients with PTC with oncocytic change presented with a higher recurrence rate and were more likely to be obese. These findings suggest that presence of oncocytic change is a poor prognostic factor in PTC patients, even if the oncocytic change involves less than 75% of a tumour.

Clinicopathological factors increased the risk of malignancy in thyroid nodules with atypical or follicular lesions of undetermined significance (AUS/FLUS) risk factor of malignancy in thyroid nodule with AUS/FLUS

PURPOSE

Ultrasound-guided fine needle aspiration (US-FNA) in thyroid nodules is presently most commonly used to identify whether these nodules are benign or malignant. However, atypical or follicular lesions of undetermined significance (AUS/FLUS), as categorized in the Bethesda System for reporting the results of FNA, cannot be classified as benign or malignant. Therefore, several clinical factors should be considered to assess the risk of malignancy in patients with AUS/FLUS. The purpose of the present study was to determine which clinical factor increased the risk of malignancy in patients with AUS/FLUS.

METHODS

A retrospective study was done on 129 patients with fine needle aspiration categorized as AUS/FLUS from January 2011 through April 2015. Univariate and multivariate analyses were performed to assess the independent effect of risk factors such as age, sex, size of nodule, atypical descriptors, and ultrasonography criteria for malignancy.

RESULTS

We identified that the presence of spiculated margin (odds ratio [OR], 5.655; 95% confidence interval [CI], 2.114-15.131; P = 0.001), nuclear grooving (OR, 3.697; 95% CI, 1.409-9.701; P = 0.008), irregular nuclei (OR, 3.903; 95% CI, 1.442-10.560; P = 0.001) were shown to be significantly related to malignancy on univariate and multivariate analyses.

CONCLUSION

We recommend that surgical resection of thyroid nodules be considered in patients with AUS/FLUS showing the histologic findings such as nuclear grooving, irregular nuclei along with spiculated margin of ultrasonographic finding.

Malignancy risk of oncocytic changes in thyroid nodules: who should we offer surgery to?

Background Oncocytic (Hürthle) cell in fine-needle aspiration biopsy (FNAB) remains challenging for surgeons. Surgical treatment is recommended for oncocytic change in FNAB, since it can sometimes be a struggle to determine the nature of thyroid nodules. We aimed to investigate the clinical significance of oncocytic changes in FNAB in terms of management of patients. Methods The FNAB samples of 172 patients with thyroid nodules were reviewed. Of these, 39 patients with cytologic findings of oncocytic changes on FNAB [POC: predominance of oncocytic cells; SFON-H: suspicious for follicular or oncocytic neoplasm (Hürthle cell type), SM-O: suspicious for malignancy-papillary or follicular carcinoma; oncocytic variant)] were included. Results FNAB demonstrated POC in 14 (35.8%), SFON-H in 15 (38.4%), and SM-O in 10 (25.6%) patients. The overall malignancy rate was 35.8% (n = 14). Clinical and laboratory data were not found to be associated with thyroid cancer while nodule size was significantly higher in patients with thyroid malignancy (15.2 versus 23.3 mm, p = 0.032). Regarding FNAB results including oncocytic changes, the rate of malignancy was significantly different and almost three-fold higher in nodules classified as SFON-H and SM-O [48% versus 14.2% with POC, p = 0.044]. Besides, there was a positive correlation between SFON-H and SM-O cytology and malignancy (p = 0.036, r = 0.337). Conclusions It is hard to discern the significance of oncocytic changes in FNAB report and to determine an optimal approach as a surgeon. We recommend surgery for the patients with an FNAB showing SFON-H and SM-O whereas POC should be better to be followed-up.

Hurthle Cell Lesion: Controversies, Challenges, and Debates

Hurthle cell lesion is one of the most questionable clinico-pathological entities in most of its aspects. Literature has used the terms oncocytic, oxyphilic, Hurthle, and Ashkanazy interchangeably; what does each term denote? Who first described these cells? What is the cell of origin? How much Hurthle cells should be present to define the lesion as Hurthle cell one? Is it possible to differentiate hyperplastic from neoplastic and benign from malignant Hurthle cell lesion on a non-histopathologic ground? Does it belong to follicular or to papillary neoplasms or should it be classified separately? Can we anticipate its clinical behavior or predict its outcome? How can we manage? We will try to answer these questions in light of the ongoing relevant arguments with the aim of resolving some uncertainties and suggesting how to solve others.

Cytomorphologic features and ultrasonographic characteristics of thyroid nodules with Hurthle cells

This study was designed to evaluate the ultrasonographic and histopathologic features of nodules composed predominantly of Hurthle cells detected during cytological examination. Fifty-seven patients with thyroid nodules composed predominantly of Hurthle cells on fine needle aspiration cytology were retrospectively analyzed. Patients were evaluated by thyroid ultrasonography (US), and biopsy samples taken by US-guided fine needle aspiration cytology were assessed histopathologically. There were 57 patients and 57 nodules with Hurthle cells in cytological examination; 49 (86%) were classified as Bethesda 1, and 8 (14%) were classified as Bethesda 3. Histopathologically, 45 (78.9%) nodules were benign and 12 (21.1%) were malignant. Nuclear groove, transgressing blood vessel, and absence of colloid were observed with a higher frequency in malignant nodules compared to benign nodules (P < .05). There were no specific morphological features (nodule echogenity, presence of microcalsification, presence of cystic areas, absence of halo, margin irregularity, and increased blood flow) predicting malignancy in the US evaluation of nodules including Hurthle cells. Nuclear groove, transgressing blood vessel, and absence of colloid on cytomorphological evaluation are indicative of malignancy in nodules containing Hurthle cells.

Preoperative serum thyroglobulin concentration as a predictive factor of malignancy in small follicular and Hürthle cell neoplasms of the thyroid gland

BACKGROUND

Cytologic examination of a fine-needle aspiration biopsy specimen cannot distinguish between benign and malignant follicular or Hürthle cell neoplasms. Serum thyroglobulin (Tg) concentrations are higher in follicular and Hürthle cell carcinomas than in benign follicular or Hürthle cell tumors, but preoperative measurement of Tg is not recommended for initial evaluation of thyroid nodules. The aim of this study was to find out whether preoperative serum Tg concentration is a predictive factor of malignant disease in patients with a follicular or Hürthle cell neoplasm with a diameter of 2 cm or less.

METHODS

From 1988 to 2013, a total of 244 patients (214 female, 30 male, age range 9 to 82 years, median age 52 years) had a surgical procedure at our institute because of follicular or Hürthle cell neoplasms with a tumor diameter of 2 cm or less. In these patients a preoperative concentration of Tg was determined and Tg-autoantibodies were negative. The risk factors for malignancy were identified by a chi-square test and multivariate logistic regression.

RESULTS

The histopathologic diagnoses were carcinoma, adenoma, and benign goiter in 62 (25.5%), 115 (47%), and 67 (27.5%) patients, respectively. The median preoperative Tg concentration in benign tumors, papillary carcinomas, follicular carcinomas, and Hürthle cell carcinomas was 41, 87, 72, and 106 ng/ml (P = 0.05), respectively. The predictive factors for carcinoma shown by the chi-square test were: sex, thyroid volume, and preoperative Tg concentration. The independent predictors of malignancy as shown by multivariate logistic regression were: male sex (odds ratio, 2.57; P = 0.02), and a Tg concentration of more than 80 ng/ml (odds ratio, 2.35; P = 0.005).

CONCLUSION

The independent predictors of malignancy in follicular or Hürthle cell neoplasms are sex and preoperative Tg concentration.

Surgery for thyroid cancer

The incidence of thyroid cancer, particularly papillary thyroid cancer, is rising at an epidemic rate. The mainstay of treatment of most patients with thyroid cancer is surgery. Considerable controversy exists about the extent of thyroid surgery and lymph node resection in patients with thyroid cancer. Surgical experience in judgment and technique is required to achieve optimal patient outcomes.

Clinical characteristics as predictors of malignancy in patients with indeterminate thyroid cytology: a meta-analysis

Indeterminate thyroid nodules (ITN) constitute the gray zone of thyroid fine-needle aspiration cytology (FNAC). About 70-80 % of ITN are later diagnosed as benign; therefore, it is very important to identify the predictors of malignancy. Aim of the study was to summarize published data about clinical risk factors for malignancy in patients with ITN and thereby provide more robust estimates of the effect of these risk factors. Sources comprised studies published through December 2012. Original articles that investigated clinical parameters as potential predictors of malignancy in ITN were identified. Two authors performed the data extraction independently. A meta-analysis of 19 relevant studies was conducted that included 3,494 patients with ITN according to FNAC. The pooled prevalence of malignancy was 28 % (95 % CI 23-33), 26 % in females and 34 % in males. The pooled OR was 1.51 (95 % CI 1.2-1.83) for males and 0.68 (95 % CI 0.53-0.88) for females. Regarding the nodule's size, the pooled OR was 2.10 (95 % CI 1.26-3.50) for nodules >4 cm in diameter. Analysis of the patient age as a risk factor was not feasible because of marked difference found between the studies. In patients with indeterminate thyroid nodules diagnosed at FNAC, the pooled rate of malignancy from 19 studies was 28 %. Patients that are male and have ITN greater than 4 cm in diameter should be considered at higher risk of cancer.

The frequency of malignancy and the relationship between malignancy and ultrasonographic features of thyroid nodules with indeterminate cytology

Various approaches are available for the management of nodules that are evaluated to be indeterminate according to the results of thyroid fine needle aspiration biopsy. The present study aimed to determine the rate of malignancy and the ultrasonographic features that could be used as predictor of malignant pathologies at the nodules with indeterminate cytology. A total of 201 patients who underwent total thyroidectomy and whose fine needle aspiration biopsy results were evaluated to be Hurthle cell lesion (n = 99), follicular neoplasm (n = 61) and [corrected] suspicious for malignancy (n = 41) were enrolled in this study. Of these patients, 178 were females (88.6 %) and 23 were males (11.4 %). The rates of malignancy were found to be 33.3 % in the Hurthle cell lesion group, 23.0 % in the follicular neoplasm group and 53.7 % in the suspicious for malignancy group (p = 0.006). The comparison of the ultrasonographic characteristics of the malignant and benign nodules revealed hypoechogenicity and microcalcification to be more common in malignant nodules (34.3 vs. 16.9 %, p = 0.005; 27.1 vs. 13.1 %, p = 0.014; respectively). While 92.3 % of the malignant nodules were ≥1 cm, 82.9 % of the benign nodules were ≥1 cm (p = 0.042). We believe that as the patients at Hurthle cell lesion group have higher risk of malignancy than the patients with Follicular Neoplasia so total thyroidectomy will be suitable for these patients. [corrected]. In addition, microcalcification and hypoechoic nodules at patients with indeterminate cytology can be related with increased risk of malignancy. [corrected].

New developments in the diagnosis and treatment of thyroid cancer

Thyroid cancer exists in several forms. Differentiated thyroid cancers include those with papillary and follicular histologies. These tumors exist along a spectrum of differentiation, and their incidence continues to climb. A number of advances in the diagnosis and treatment of differentiated thyroid cancers now exist. These include molecular diagnostics and more advanced strategies for risk stratification. Medullary cancer arises from the parafollicular cells and not the follicular cells. Therefore, diagnosis and treatment differs from those of differentiated thyroid tumors. Genetic testing and newer adjuvant therapies have changed the diagnosis and treatment of medullary thyroid cancer. This review will focus on the epidemiology, diagnosis, workup, and treatment of both differentiated and medullary thyroid cancers, focusing specifically on newer developments in the field.

Does Hürthle cell carcinoma of the thyroid have a poorer prognosis than ordinary follicular thyroid carcinoma?

BACKGROUND

Hürthle cell carcinoma (HCC) is a rare form of thyroid carcinoma and is considered an oxyphilic variant of follicular thyroid carcinoma. However, little is known about its biological characteristics or clinical behavior. We conducted a retrospective study to determine whether the prognosis of HCC differs from that of ordinary follicular thyroid carcinoma (OFC).

METHODS

The subjects were the 558 patients with follicular thyroid carcinoma who underwent initial surgery at our institution between 1989 and 2010 and consisted of 73 patients with HCC and 485 patients with OFC. There were 410 females and 148 males, and their median age was 51 years. A univariate analysis was conducted in relation to cumulative cause-specific survival (CSS) according to the Kaplan-Meier method for the following variables: age at the time of initial surgery, gender, tumor size, invasiveness, distant metastasis at presentation, and histological type (HCC vs OFC). Differences between groups were analyzed for significance by the log-rank test. Multivariate analysis was performed by using the Cox proportional hazard model.

RESULTS

A total of 4 patients (5.5%) in the HCC group had distant metastasis compared with 106 patients (21.9%) in the OFC group. Significant factors in relation to CSS in the univariate analyses were age, tumor size, and invasiveness, but there were no significant differences between the HCC group and the OFC group. Multivariate analysis showed that age, tumor size, and distant metastasis at presentation were significant factors.

CONCLUSIONS

HCC does not have a poorer prognosis than OFC.

Surgeon-performed ultrasound predictors of malignancy in patients with Hürthle cell neoplasms of the thyroid

BACKGROUND

Fine-needle aspiration cannot reliably determine malignancy in patients with Hürthle cell neoplasms (HCNs) of the thyroid. Thyroid nodule size and characteristics determined by surgeon-performed ultrasound (SUS) may be useful for predicting malignancy in HCN preoperatively. This study examined whether tumor size and features by SUS can reliably predict malignancy in patients with HCN.

MATERIALS AND METHODS

We performed a retrospective review of 84 patients with HCN by fine-needle aspiration, who underwent SUS and thyroidectomy from 2002 to 2010. All patients underwent thyroid lobectomy with isthmusectomy unless there was a history of radiation exposure, familial thyroid cancer, obstructive symptoms, bilateral nodules, and/or patient preference, in which case total thyroidectomy was performed. Tumor size and malignant features by SUS were correlated with final histopathology using multivariate regression analysis.

RESULTS

On final histopathology, 29 patients had malignant thyroid nodules and 55 patients had benign ones. There were no statistically significant differences in terms of age, race, ethnicity, or gender between HCN patients who revealed malignant or benign nodules on final pathology. Tumor size ≥ 4 cm measured by SUS did not predict malignancy in HCN. Hypoechogenicity and hyperechogenicity were significantly associated with malignancy, whereas isoechogenicity was predictive of benignity (P = 0.044). No other ultrasonographic features were predictive for thyroid carcinoma by multivariate analysis.

CONCLUSIONS

Tumor size and features determined by SUS do not reliably predict malignancy in patients with HCN. Such patients at risk for malignancy should initially undergo thyroid lobectomy for definitive diagnosis.

Hemithyroidectomy is the preferred initial operative approach for an indeterminate fine needle aspiration biopsy diagnosis

BACKGROUND

Fine needle aspiration biopsy represents the critical initial diagnostic test used for evaluation of thyroid nodules. Our objectives were to determine the cytological distribution, the utility of clinicopathologic characteristics for predicting malignancy and the true proportion of cancer among individuals who presented with indeterminate cytology and had undergone thyroid surgery for suspicion of cancer.

METHODS

We retrospectively reviewed 1040 consecutive primary thyroid operations carried out over an 8-year period at a tertiary care endocrine referral centre. Follicular neoplasm (FN), Hürthle cell neoplasm (HN), neoplasms suspicious for but not diagnostic of papillary carcinoma (IP) and neoplasms with cellular atypia (IA) were reviewed.

RESULTS

In all, 380 individuals presented with cytologically indeterminate thyroid nodules. Of these, 252 (66%) patients had FN, 47 (12%) HN, 44 (12%) IP, 26 (7%) IA and 11 (4%) had mixed diagnoses. Biopsied lesions were found to be malignant on pathological evaluation in 102 (27%) patients: 49 (19%) with FN, 11 (23%) HN, 28 (64%) IP and 9 (35%) with IA. Hemithyroidectomy was adequate definitive treatment in 196 of 225 (87%) patients with FN and 39 of 42 (93%) with HN. Significant associations with a cancer diagnosis were identified for smaller tumour size in patients with FN (p = 0.004) and right thyroid lobe location in patients with IP (p = 0.012), although these factors were nonsignificant in the corrected analyses for multiple comparisons.

CONCLUSION

In a review of the experience at a Canadian centre, 4 operations were carried out to identify each cancer, and hemithyroidectomy was the optimal initial and definitive surgical approach for most patients.

Can abundant colloid exclude oncocytic (Hürthle cell) carcinoma in thyroid fine needle aspiration? Cytohistological correlation of 127 oncocytic (Hürthle cell) lesions

OBJECTIVE

The objective of the present study was to find out whether the presence or absence of certain cytological features can exclude oncocytic (Hürthle cell) carcinoma in thyroid fine needle aspiration (FNA) to minimize unnecessary surgery.

METHODS

Over a 17-year period, 127 hypercellular, oncocyte-exclusive, lymphocyte-absent aspirates obtained via ultrasound-guided FNA with on-site assessment had histology slides for review. The presence or absence of six cytological features (microfollicular arrangement, discohesive single cells, small cell dysplasia, large cell dysplasia, transgressing blood vessels and colloid) and one histological feature (macrofollicular component) were determined for each case independently by two cytopathologists.

RESULTS

Histology showed 12 (9.4%) cases of Hashimoto thyroiditis, 23 (18.1%) oncocytic adenomatoid nodules in nodular goitre, 66 (52.0%) oncocytic adenomas and 26 (20.5%) oncocytic carcinomas (13 minimally invasive without angioinvasion, six minimally invasive with angioinvasion, seven widely invasive). Histologically, a macrofollicular component was present in seven of 26 (26.9%) oncocytic carcinomas, including one case with abundant thin colloid. A microfollicular arrangement, discohesive single cells, small cell dysplasia, large cell dysplasia and transgressing vessels were present in oncocytic carcinoma, oncocytic adenoma and oncocytic adenomatoid nodules in nodular goitre.

CONCLUSIONS

A macrofollicular component is frequently present in oncocytic carcinoma, oncocytic adenoma and oncocytic adenomatoid nodules in nodular goitre. None of the cytological features studied, including abundant colloid, can exclude oncocytic carcinoma. Oncocytic carcinoma can only be excluded by thorough histological examination of thyroidectomy specimens. A molecular marker is needed to triage oncocytic lesions in thyroid FNA.

The significance of hurthle cells in thyroid disease

Hürthle cells (HCs) and HC change, along with the frequently employed synonyms "oncocytes/oncocytic change" or "oxyphils/oxyphilic change," are not infrequently described on fine-needle aspiration biopsy (FNAB) reports of thyroid lesions. The description of HCs on FNAB reports may cause significant concern to the clinician; however, placing the finding in the appropriate clinical context may alleviate some anxiety. Not all oxyphilic cells are true HCs and not every aspirate containing HCs is or should be considered equivalent to an HC neoplasm (HCN). There are many benign thyroid lesions associated with HCs or HC change. For clinicians, it may be difficult to discern the significance of these findings and to determine an appropriate course of action. A skilled and experienced cytopathologist is invaluable in discriminating the subtle features that distinguish these lesions from those warranting a more aggressive approach. The diagnosis of HC carcinoma relies on histopathologic scrutiny and evidence of capsular and/or vascular invasion or metastasis to lymph nodes or distant organs. Many investigators have sought clinical, radiographic, cytological, genetic, and other factors to attempt to discriminate preoperatively between benign and malignant HCNs. To date, none have been definitively proven to be reliable. For now, because of the inability to determine the benign or malignant nature of such neoplasms based on cytology alone, a surgical approach is warranted.

Multi-targeted approach in the treatment of thyroid cancer

While accounting for only 1% of solid organ malignancies (9% in women), thyroid carcinoma is the most common malignancy of the endocrine system. Although most patients have a favorable prognosis, over 1,500 people will die from thyroid carcinoma each year. The spectrum of disease types range from papillary thyroid cancer, which is a well-differentiated indolent tumor, to anaplastic carcinoma, a poorly differentiated fulminant cancer. With advances in diagnostic methods, surgical techniques, and clinical care of patients with thyroid carcinoma, the current management of thyroid cancer demands a multidisciplinary approach. The majority of patients with well-differentiated thyroid carcinoma of follicular cell origin are cured with adequate surgical management; however, some thyroid malignancies such as medullary thyroid carcinoma (MTC) or poorly differentiated thyroid carcinomas frequently metastasize, precluding patients from a curative resection. As such, novel palliative and therapeutic strategies are needed for this patient population. Here, we explore the current management of thyroid carcinoma, including surgical management of the primary tumor, lymph node disease, and locoregional recurrence. Likewise, we explore the application of current molecular techniques, reviewing nearly two decades of data that have begun to elucidate critical genetic pathways and therapeutic drug targets which may be important in specific thyroid tumor types.

Fine needle aspiration of the thyroid: correlation with final histopathology in a surgical series of 797 patients

BACKGROUND

Fine needle aspiration (FNA) is accepted as the diagnostic procedure of choice in the management of patients with thyroid nodules. Follicular/Hürthle cell neoplasms have traditionally been grouped under the category of indeterminate FNA results. This study examined the experience with FNA in a large cohort of patients undergoing thyroidectomy before adoption of the Bethesda system for reporting thyroid cytopathology (BSTC) at a single academic medical center.

STUDY DESIGN

A retrospective review of prospectively collected data of 797 consecutive patients with dominant nodules >1 cm who underwent FNA and thyroidectomy from 2003 to 2009 was performed. Patients were categorized into groups based on FNA results: malignant, benign, indeterminate, and nondiagnostic. The indeterminate group had FNA results that included follicular neoplasm, Hürthle cell neoplasm, and suspicion of papillary thyroid cancer. FNA results were compared with final histopathology after thyroidectomy.

RESULTS

FNA results included 147 (18%) positive for malignancy, 255 (32%) benign, 358 (45%) indeterminate, and 37 (5%) nondiagnostic. The overall malignancy rate on final histopathology was 369 of 797 (46%). Overall, there was a false positive rate of 2% and false negative rate of 8.6%. Among the 358 indeterminate FNA results, carcinoma was found in 81 (36%) of 223 follicular neoplasms, 18 (36%) of 50 Hürthle cell neoplasms, and 78 (92%) of 85 that were suspicious for papillary thyroid cancer. When FNA was nondiagnostic, cancer was present in 9 of 37 (24%). Among 39 patients with benign FNA who had cancer on final histopathology, 22 of 255 (8.6%) had cancer in the index thyroid nodule, and 81% of cancers were >1 cm.

CONCLUSIONS

Patients with FNA and dominant nodules >1 cm, who underwent thyroidectomy, had an overall rate of thyroid malignancy of 46%. There was a cancer prevalence of 8.6% in patients with benign FNA results referred for surgical resection. Despite not yet implementing the BSTC at this medical center, the majority of thyroidectomies were adequately performed for indeterminate FNAs with underlying malignancy.

Predictors of Malignancy in Patients with a Thyroid Nodule That Contains Hürthle Cells

Objective. Fine needle aspiration cytology of a thyroid nodule with Hürthle cells can be present in both benign and malignant diseases of the thyroid. The aim of this study was to identify the factors that predict malignancy in patients who underwent thyroidectomy with a preoperative fine needle aspiration cytology that contains a predominance of Hürthle cells.

Study Design. Retrospective data collection.

Setting. Tertiary referral center.

Subjects and Methods. Medical records of 70 consecutive patients were reviewed between March 2005 and August 2010. Predictive factors, as well as age, gender, preoperative serum thyroid-stimulating hormone level, the microscopic findings of fine needle aspiration, ultrasonographic appearance, and size and number of nodules in the pathology report, were correlated with final histopathologic diagnosis of benign or malignant disease.

Results. Patients’ final pathology showed that 21 patients (30%) had malignant disease, of whom 15 patients (71.4%) had papillary carcinoma and 6 patients (28.6%) had Hürthle cell carcinoma. Forty-nine (70%) patients had benign disease (hyperplastic/adenomatoid nodule in 24 patients, Hashimoto thyroiditis in 18 patients, Hürthle cell adenoma in 5 patients, and follicular adenoma in 2 patients). The rate of malignancy was higher in male patients (42.9% vs 28.6%), with nodules measuring ≥2 cm (36.7% vs 25.0%), the presence of a solitary nodule (34.3% vs 27.7%), and the presence of metaplasia in fine needle aspiration (36.4% vs 27.1%), although none was found to be significant ( P > .05).

Conclusion. Thyroid nodules that are reported in cytology as Hürthle cell lesions require surgery to differentiate benign from malignant disease.

Hurthle cell carcinoma of the thyroid

A 63-year-old man consulted for a non-toxic thyroid nodule of 2 years' duration. Fine needle aspiration revealed cell findings consistent with papillary thyroid carcinoma. He eventually underwent total thyroidectomy. Microscopic examination revealed histologic features of Hurthle cell carcinoma of the thyroid. He received radioactive iodine therapy and suppressive levothyroxine treatment. Post-therapy whole body iodine-131 scan revealed thyroid tissue remnants limited to the anterior neck. Four months after radioactive iodine therapy, thyroglobulin level is low and the patient remains to have no evidence of disease.

Tumor size and age predict the risk of malignancy in Hürthle cell neoplasm of the thyroid and can therefore guide the extent of initial thyroid surgery

BACKGROUND

The majority of patients having a diagnosis of Hürthle cell neoplasm (HCN) on fine-needle aspiration (FNA) of a thyroid nodule have a diagnostic thyroid lobectomy to make the final diagnosis. If the nodule is malignant, they require a completion thyroidectomy. The objective of this study was to devise a simple clinical scheme capable of predicting malignancy in patients with cytologic diagnosis of HCN and, therefore, guide the extent of initial thyroid surgery.

METHODS

A total of 57 patients who underwent thyroid surgery after an FNA diagnosis of HCN were retrospectively studied. The patients were examined for clinical features, preoperative imaging studies, and pathology reports. The risk of malignancy was calculated using a multiple logistic regression model.

RESULTS

The overall rate of malignancy in patients with HCN was 46% (26/57). The predictors of malignancy based on multiple logistic regression analysis were tumor size >1.5 cm (odds ratio [95% confidence interval] = 8.0 [1.9-33.4]) and patient age >45 years (odds ratio [95% confidence interval] = 2.3 [0.6-8.6]). In patients with nodules larger than 1.5 cm, the predicted probability of malignancy was greater in patients over 45 years than in younger patients (65% for >45 years vs. 44% for ≤45 years). In patients with a nodule 1.5 cm or less, the probability of malignancy was relatively low and not significantly different between the two age categories (18% for >45 years vs. 10% for ≤45 years).

CONCLUSIONS

This study suggests that tumor size and age can be integrated into decision making for patients with an FNA diagnosis of HCN to facilitate patient selection for surgical referral and, particularly, to determine in which patients a thyroidectomy rather than a lobectomy should be the initial surgery.

Age and tumor size predicts lymph node involvement in Hürthle Cell Carcinoma

Introduction: Hürthle cell carcinoma (HCC) is a rare tumor that tends to metastasize to the lymph nodes. Some studies have correlated size of Hürthle cell tumors with the risk of malignancy. Whether the size of HCC correlates with the risk of lymph node (LN) metastases, to our knowledge has not been addressed.

Methods: A retrospective analysis was performed on all patients diagnosed with HCC on final pathology between 1997 and 2008. The tumor size and lymph node status was obtained for each patient. The data were analyzed utilizing Student's t-test and the Fisher's exact test to calculate the two-tailed p-value.

Results: Out of 39 patients diagnosed with HCC 3(8%) had LN metastases; 1 had ipsilateral central LN metastasis and 2 had ipsilateral central and lateral LN metastasis. LN dissection was performed in patients with known metastasis (2 were evident on preoperative ultrasound and 1 intraoperatively). Patients with LN metastasis were older than those without (mean age: 86.7 and 56.4 years, respectively), had larger tumors (mean size: 6 and 4 cm) and were commonly male (2 of 3). No tumor < 5cm presented with lymph node involvement (3/15 with >5cm cancer had node metastasis, 0/24 with <5cm cancer had node metastasis).

Conclusions: Similar to what has been found in patients with papillary thyroid cancer, older male patients with Hürthle cell carcinomas greater than 5cm are more likely to have lymph node metastasis. Our data suggest that these patients may benefit from a prophylactic ipsilateral central neck dissection at the time of their initial operation.

Ultrasonographic evaluation of thyroid nodules: comparison of ultrasonographic, cytological, and histopathological findings

Thyroid ultrasonography (US) and fine needle aspiration biopsy (FNAB) are the most important tools in evaluating thyroid nodules. A total of 3,404 nodules in 2,082 cases referred to our clinic between 2005 and 2008 were analyzed retrospectively. Considering US features of nodules, risk factors predicting malignancy were: margin irregularity as the most important predictor, hypoechoic pattern and microcalcification (Odds ratios: 63.2, 13.3, 7.03, respectively). Cytologic results of the patients were as follows: 1,718 (82.5%) benign, 196 (9.4%) suspicious, 68 (3.3%) nondiagnostic, and 100 (4.8%) malignant. In histopathologic examination, we determined a malignancy rate of 7.59% (158/2082). We calculated the sensitivity of FNAB as 89.16%, specificity as 98.77%, positive predictive value as 96.10%, negative predictive value as 96.39%, and accuracy as 96.32%. In cytologic examination, the malignancy rate of subcentimetric (≤1 cm) nodules was higher than supracentimetric (>1 cm) nodules (5.1% vs. 1.5%, P = 0.001). In postoperative histopathologic examination, although the malignancy rate of subcentimetric nodules was higher than that of supracentimetric nodules, the difference was statistically insignificant (5.5%, 4.4%, respectively; P > 0.05). Cytologically diagnosed malignancy was detected in 4.5% of patients with multiple nodules, while it was present in 6% of patients with solitary nodule indicating no significant difference. However, postoperative histopathologic examination revealed a significantly higher malignancy rate in patients with solitary nodule compared to in patients with multiple nodules (11.7%, 6.5%; respectively, P < 0.001). The malignancy rate of patients operated for suspicious cytology was found to be 46.15%; for nondiagnostic cytology, it was 64.29%. In conclusion, ultrasonographically, hypoechoic pattern, microcalcification and margin irregularity of thyroid nodules are important features in determining the malignancy risk. The nodule size alone still remains inadequate to exclude malignancy risk.

Hurthle cell tumours of the thyroid. Personal experience and review of the literature

Hurthle cell carcinoma represents about 5% of differentiated thyroid carcinomas. The prognosis of the malignant type of the tumour is still under debate as some Authors have reported that Hurthle cell adenoma occasionally behaves like Hurthle cell carcinoma. Aim of the present study was to evaluate previously reported data and personal experience on the clinical and pathological features of patients affected by Hurthle cell tumour that may predict disease progression and death. In the literature, factors potentially associated with decreased survival were identified and include: age, disease stage, tumour size, extra-glandular invasion, lymph node disease, distant metastases, extensive surgery, radioiodine treatment. From 1992 to 2003, the Authors identified 28 patients affected by Hurthle cell tumour, 9 with Hurthle cell adenoma and 19 with Hurthle cell carcinoma. Of these, 22 were females and 6 males. Mean age of patients affected by adenoma was 49.7 years (range 30-72) vs. 49.3 years (range 15-72) in Hurthle cell carcinoma patients. In all patients, total thyroidectomy was performed. At histology, 9 adenomas, 5 "minimally invasive" and 14 invasive carcinomas were found. Post-operatively, in Hurthle cell carcinoma patients, TNM staging showed 9 patients with stage I, 5 stage II, 4 stage III and one stage IVa (UICC, 2002). All invasive carcinomas underwent (131)I therapy (91-585 mCi). One Hurthle cell carcinoma patient received external beam radiotherapy. The mean follow-up period was 62 months (range 6-324). Relapse was not observed in any of the cases with adenoma. Only one Hurthle cell carcinoma patient showed distant lung metastases at 60 months' follow-up. In conclusion, Hurthle cell carcinoma was not found to present a more aggressive behaviour than follicular carcinoma, when risk factors, including extent of tumour invasion, were taken into account. None of the patients with Hurthle cell adenoma showed a relapse or death caused by the tumour.

Clinical efficacy of fine-needle aspiration biopsy of thyroid nodules in males

BACKGROUND

It has recently been suggested that the use of fine-needle aspiration (FNA) biopsy of thyroid nodules in male patients is associated with an unacceptably high false-negative rate in the detection of thyroid malignancy. We hypothesize that FNA biopsy is an accurate preoperative tool for detecting thyroid cancer in men, and that false negative rates are significantly lower than recently reported.

MATERIALS AND METHODS

A retrospective database analysis was performed on all male patients who underwent thyroid surgery from May 1994 through January 2007 at a single institution. The results of preoperative FNA biopsies were compared with final surgical pathologic results. FNA biopsy results were reported as benign, malignant, inconclusive (i.e., follicular neoplasm), or nondiagnostic; final surgical pathology was reported as benign or malignant.

RESULTS

Of 1205 patients who underwent thyroidectomy, 273 (23%) were male. Preoperative FNA biopsy results were obtained in 60% of these male patients and were read as benign in 45/165 (27%) patients, malignant in 47/165 (28%) patients, inconclusive in 66/165 (40%) patients, and nondiagnostic in 7/165 (4%) patients. In male patients with cytology reported as benign, 3/45 (6.7%) FNAs were determined to be malignant on final pathology.

CONCLUSIONS

Our study determined that FNA biopsy of thyroid nodules in male patients has an acceptably low false-negative rate of 6.7% and is, therefore, an accurate and useful diagnostic tool. We recommend preoperative FNA biopsy for all male patients presenting with thyroid nodules as a standard of practice.

A meta-analysis of comparing fine-needle aspiration and frozen section for evaluating thyroid nodules

The literature on comparing fine-needle aspiration (FNA) and frozen section for evaluating thyroid nodules was reviewed. Publications on this subject were divided into three groups (follicular lesions, non-follicular lesions and thyroid lesions, not otherwise specified). A meta-analysis was done to compare sensitivity, specificity, and positive and negative predictive values between FNA and frozen section diagnoses. For follicular lesions, FNA was much more sensitive but less specific, with lower positive predictive value than frozen section. FNA and frozen section are virtually identical in all parameters of accuracy in evaluating thyroid nodules that are not follicular lesions. The third group of publications that did not separate/specify follicular lesions from non-follicular lesions was non-contributory.

Comparison of malignancy rate in thyroid nodules with cytology of indeterminate follicular or indeterminate Hürthle cell neoplasm

BACKGROUND

Thyroid nodules that are read on cytology as follicular or Hürthle cell neoplasms (FN and HN, respectively) and indeterminate for malignancy require surgery to differentiate benign from malignant nodules. We analyzed FN and HN with indeterminate cytology to determine if there were differences in the rate and types of thyroid malignancy and if the rate of thyroid malignancy was influenced by age or sex.

METHODS

We analyzed 463 nodules with an indeterminate cytological diagnosis of FN and 140 nodules with an indeterminate cytological diagnosis of HN. The histopathological diagnosis after thyroidectomy was the method for establishing the diagnosis and type of malignancy.

RESULTS

For the entire series of 603 patients there were 106 (17.6%) with thyroid cancer; 80 of these had a cytology reading of FN and 26 had HN. Extrathyroidal invasion in the grouped HN and FN patients who had papillary thyroid carcinoma (PTC) was more common in females than in males (62% vs. 25 %, p < 0.05). The rate of thyroid cancer was similar in FN (17.3%) and HN (18.6%). The rate of Hürthle cell thyroid cancer was significantly higher in HN than in FN (5.0% vs. 0.7%, p < 0.01) and the rate of the oncocytic variant of PTC was also significantly greater in HN compared to FN nodules (23.1% vs. 1.7%, p < 0.05). The rate of follicular thyroid carcinoma was almost identical in patients with HN and FN (19.2% vs. 18.8 %).

CONCLUSIONS

There is little difference in the rate of malignancy between thyroid nodules with a cytological reading of FN indeterminate for malignancy and HN indeterminate for malignancy but there is a difference in the types of thyroid cancers in these groups. Hürthle cell thyroid cancer and the oncocytic variant of PTC is more common in nodules with an HN indeterminate for malignancy cytology reading than in nodules with a FN indeterminate for malignancy cytology reading. Since Hürthle cell thyroid cancer and the oncocytic variant of PTC are more aggressive than other thyroid cancers, it is likely that patients with an HN indeterminate for malignancy cytology will, as a group, have more aggressive thyroid cancers than those with an FN indeterminate for malignancy cytology.