Endocrine tumors: evaluation of the thyroid nodule

Comparison between Fine Needle Aspiration Cytology with Histopathology in the Diagnosis of Thyroid Nodules

BACKGROUND

Accurate diagnosis of thyroid nodules is crucial for avoiding unnecessary surgeries and enabling timely treatment. Fine needle aspiration cytology (FNAC) and ultrasound are commonly employed diagnostic techniques, but their reliability is debated. This study aimed to compare the diagnostic accuracy of FNAC and ultrasounds using histopathology as the reference standard.

METHODS

A retrospective review was conducted on 344 patients who underwent thyroidectomy between January 2017 and May 2022. An ultrasound and FNAC were performed before surgery, and histopathological findings were compared. Statistical analyses were conducted to calculate sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), false positive rate, false negative rate, and overall accuracy for each diagnostic method.

RESULTS

Among the study population, 38.67% of thyroid tumors were malignant. Ultrasound showed a sensitivity of 68.18%, specificity of 76.55%, PPV of 64.74%, NPV of 79.20%, and overall accuracy of 73.31%. FNAC had a sensitivity of 89.31%, specificity of 48.44%, PPV of 78%, NPV of 68.89%, and accuracy of 75.89%. The correlation coefficient between ultrasound and FNAC was 0.512 (p < 0.0000001). Ultrasound correlated with histopathology with a coefficient of 0.408 (p < 0.0000001), while FNAC with histopathology had a coefficient of 0.304 (p < 0.00001). The correlation coefficient between these three diagnostic methods was 0.423 (p < 0.0001).

CONCLUSION

In the diagnosis of thyroid nodules, both FNAC and ultrasound demonstrated moderate diagnostic accuracy. Ultrasound showed a higher specificity, while FNAC exhibited a higher sensitivity. Combining these techniques may improve diagnostic accuracy. Further research and the development of more reliable diagnostic methods are warranted to optimize the management of thyroid nodules and avoid unnecessary surgeries.

Post-radiotherapy cribriform-morular thyroid carcinoma

BACKGROUND

According to the new 2022 World Health Organization classification of endocrine tumors, thyroid malignancy, formerly known as the cribriform-morular variant of papillary thyroid carcinoma, is now categorized as differentiated thyroid malignancy; it is, at present, called cribriform-morular thyroid carcinoma and classified as a tumor of unknown histogenesis.

CASE REPORT

In this case report, we report on a 15-year-old patient who underwent external radiotherapy to the neck for Hodgkin's disease and developed cribriform-morular thyroid carcinoma 5 years after radiotherapy.

CONCLUSIONS

We believe that cribriform-morular thyroid carcinoma with diffuse nuclear beta-catenin expression has exciting and unresolved uncertainties that may affect disease prognosis and follow-up for cytopathologists and endocrinologists.

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

Environmental factors are established contributors to thyroid carcinomas. Due to their known ability to cause cancer, exposure to several organic and inorganic chemical toxicants and radiation from nuclear weapons, fallout, or medical radiation poses a threat to global public health. Halogenated substances like organochlorines and pesticides can interfere with thyroid function. Like phthalates and bisphenolates, polychlorinated biphenyls and their metabolites, along with polybrominated diethyl ethers, impact thyroid hormones biosynthesis, transport, binding to target organs, and impair thyroid function. A deeper understanding of environmental exposure is crucial for managing and preventing thyroid cancer. This review aims to investigate the relationship between environmental factors and the development of thyroid cancer.

Molecular Testing of Atypical Thyroid Nodules with Corresponding Surgical Correlation: Five-Year Retrospective Review in Veterans Population

Objective

We report the results of a retrospective five-year study within a veteran population aimed at correlating abnormal thyroid fine-needle aspiration (FNA) diagnosis with associated molecular testing to the histology of the surgical resection.

Methods

A retrospective analysis of abnormal thyroid FNAs with associated molecular testing and surgical outcome was conducted from January 1, 2015 to December 31, 2020. Aspirates were classified using the Bethesda system for reporting thyroid cytopathology, including atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), suspicious for malignancy (SM), and malignant. Pertinent data, including patient demographics, imaging, and ancillary testing were reviewed. A thyroid cancer mutation panel assessing the most common mutations and rearrangements associated with neoplasia was utilized. The results of molecular testing were directly compared and correlated with final cytological and histological diagnosis.

Results

A total of 1850 thyroid aspirates were performed, 200 of which were given an abnormal cytologic diagnosis. Thirty-six samples were submitted for molecular testing and subsequent surgical follow-up. Four were called malignant on cytology. 32 were placed in an indeterminate category (89%). Within indeterminate cases: 53% exhibited positive molecular mutations (n=17), 34% no mutation detected (n=11), and 13% insufficient quantity for testing (n=4). Upon surgical resection in the mutation-positive group: 18% had no malignancy (n=3), and the remaining 82% were positive for malignancy (n=14). Mutations in the histologically malignant group included: 57% BRAF (n=8), 21% NRAS (n=3), 7% HRAS (n=1), 7% KRAS (n=1), and 7% PAX8/PPAR gamma (n=1). In indeterminate cases with no mutation detected, 10 cases were found to be benign, and one case of malignancy was diagnosed. The probability of indeterminate diagnosis in combination with no mutation yielded a 91% chance of benign entity and 9% chance of malignancy. We demonstrated 93% sensitivity and 91% negative predictive value (NPV) for the risk of malignancy in indeterminate cytology specimens with ancillary molecular testing. There was 77% specificity and 82% positive predictive value (PPV) for our data set.

Conclusions

In indeterminate samples, the detection of a mutation was highly predictive of malignancy and a strong indicating factor for surgery with a high sensitivity and NPV. Molecular testing refined or established the diagnosis in 89% of the cases. Our results indicate that molecular testing of thyroid nodules enhances the accuracy of FNA cytology and the subsequent surgical outcome.

Impact of ultrasonographic features, cytomorphology and mutational testing on malignant and indeterminate thyroid nodules on diagnostic accuracy of fine needle cytology samples: A prospective analysis of 141 patients

OBJECTIVE

Fine needle cytology (FNC) is the first-line diagnostic method to determine the benign or malignant nature of thyroid nodules. The gray zone of cytological classifications remains, however, a crucial and challenging area for cytopathologists.

DESIGN, PATIENTS AND MEASUREMENTS

In the present study, 141 thyroid cytological samples, with ultrasonographic suspicious features, have been prospectively analysed. Molecular analyses were performed by an innovative technology using two multiplex PCRs for the amplification of BRAF, N-H-K-RAS and RET exon genes. RNA samples were studied for RET/PTC1 and RET/PTC3 rearrangements by PCR amplification, and the conditions were set-up to study, with a single experiment, both wild-type PAX8 and PAX8/PPARɣ rearrangements. In total, 111 samples were examined for BRAF, N-H-KRAS and RET genes. An ultrasonographic, cytological and molecular correlation was also carried out in an attempt to suggest a possible way to manage the patients with thyroid nodules. Cyto-histological correlation was available in 115 cases, and it was used to verify the global diagnostic accuracy of this combined approach.

RESULTS

According to the histopathological diagnosis, FNC accuracy was 100% for TIR5 and metastases; 89% for TIR4; 84% for TIR3A and 58% for TIR3B. About 11% of the studied samples showed either RET-PTC1 or RET/PTC3 chromosomal rearrangements, and only one sample simultaneously presented RET/PTC1 and RET/PTC3 rearrangements. PAX8/PPARɣ rearrangement was found in 6% of the samples.

CONCLUSIONS

A multidisciplinary approach to the thyroid is therefore necessary to develop innovative methods suitable for an improved diagnostic and prognostic definition of thyroid cancer.

The Effect of Fine needle aspiration on Detecting Malignancy in Thyroid Nodule

Introduction The prevalence of thyroid nodules is 4-7% in adults. Although less than 5% of nodules in adults are malignant, most nodules are non-neoplastic or benign. Fine needle aspiration (FNA) is a diagnostic technique for evaluation of non-toxic nodules, which has been widely accepted. Its primary objective is the patient triage in order to identify those who need surgery and aid in the decision of the appropriate surgical procedures. Materials and Methods This retrospective study was conducted on 116 patients who underwent thyroidectomy in Semnan's Kowsar Hospital during 2011-2018 in Iran. The data were recorded before and after the surgery in the checklist. The data were compared and the sensitivity, specificity and diagnostic accuracy of FNA were calculated. Data were analyzed by SPSS software (version 18.0) and analyzed by Chi-Square test and Independent Samples test. Results The sensitivity of FNA was 96.9%; its specificity was 81.7%; its positive predictive value (PPV) was 73.8%; its negative predictive value (NPV) was 98%; and its diagnostic accuracy was 86.9%. For the nodules smaller than 4 cm, FNA was calculated with higher sensitivity, specificity, PPV, NPV, and diagnostic accuracy compared to nodules larger than 4 cm. Conclusion FNA is a reliable screening method for preoperative assessment that can accurately detect malignant cases from benign cases, especially if the size of the nodule is smaller than 4 cm.

Thyroid Imaging Reporting and Data System Score Combined with the New Italian Classification for Thyroid Cytology Improves the Clinical Management of Indeterminate Nodules

The new Italian cytological classification (2014) of thyroid nodules replaced the TIR3 category of the old classification (2007) with two subclasses, TIR3A and TIR3B, with the aim of reducing the rate of surgery for benign diseases. Moreover, thyroid imaging reporting and data system (TI-RADS) score appears to ameliorate the stratification of the malignancy risk. We evaluated whether the new Italian classification has improved diagnostic accuracy and whether its association with TI-RADS score could improve malignancy prediction. We retrospectively analyzed 70 nodules from 70 patients classified as TIR3 according to the old Italian classification who underwent surgery for histological diagnosis. Of these, 51 were available for cytological revision according to the new Italian cytological classification. Risk of malignancy was determined for TIR3A and TIR3B, TI-RADS score, and their combination. A different rate of malignancy (p = 0.0286) between TIR3A (13.04%) and TIR3B (44.44%) was observed. Also TI-RADS score is significantly (p = 0.003) associated with malignancy. By combining cytology and TI-RADS score, patients could be divided into three groups with low (8.3%), intermediate (21.4%), and high (80%) risk of malignancy. In conclusion, the new Italian cytological classification has an improved diagnostic accuracy. Interestingly, the combination of cytology and TI-RADS score offers a better stratification of the malignancy risk.

Nodular thyroid disease in the elderly: novel molecular approaches for the diagnosis of malignancy

Epithelial thyroid cancers (TC) comprise two differentiated histotypes (DTC), the papillary (PTC) and the follicular (FTC) thyroid carcinomas which, following dedifferentiation, are assumed to give rise to the poorly differentiated thyroid carcinomas and the rare, but highly aggressive and invariably fatal, anaplastic thyroid carcinomas. Although thyroid cancer mortality has not been changed, its annual incidence has increased over the last two decades, mainly because of the improved ability to diagnose malignant transformation in small non-palpable thyroid nodules. Despite DTC patients have a favorable prognosis, aggressive disease is more frequently observed in the elderly showing a higher disease-specific mortality. Of relevance is the high prevalence of nodular thyroid disease in aged patients being higher than 90%, in women older than 60 year, and 60% in men older than 80 year. This implies a careful evaluation of thyroid nodules in this group of patients in order to exclude malignancy. In fact, despite the tremendous progress in the comprehension of the underlying molecular mechanisms deregulated in DTC progression, several aspects of their clinical management remain to be solved and novel diagnostic strategies are sorely needed. Here, we will attempt to review new molecular approaches, which are currently being exploited in order to ameliorate the diagnosis of thyroid nodules.

Management of Thyroid Nodular Disease: Current Cytopathology Classifications and Genetic Testing

Preoperative diagnosis and operative planning for patients with thyroid nodules has improved over the last decade. The Bethesda criteria for cytopathologic classification of thyroid nodule aspirate has enhanced communication between pathologists and clinicians. Multiple genetic tests, including molecular markers and the Afirma gene expression classifier, have been developed and validated. The tests, along with clinical and radiologic information, are most useful in the setting of indeterminate cytology. The development of an updated diagnostic and treatment algorithm incorporating all available tests will help standardize the management of patients with nodular thyroid disease and reduce variation and inefficiencies in care.

Diagnostic efficacy and importance of fine-needle aspiration cytology of thyroid nodules

Background:

Fine-needle aspiration cytology (FNAC) in the diagnosis of thyroid nodules is an easy and cost-effective method. The increase in malignancy rates of the excised nodules due to the high sensitivity and specificity rates of the FNAC is remarkable.

Aim:

The aim of this study was to assess the effectiveness of FNAC in the evaluation of thyroid nodules by comparing the results with histopathologic evaluation and comparing the consistency of the results with the literature.

Materials and Methods:

In this study, 1607 FNACs of 1333 patients which were classified according to the Bethesda system and 126 histopathological evaluations obtained from this group were evaluated. The mean age of the patients was 51.24 (range: 17-89, 17% male and 83% female). The sensitivity, specificity, positive and negative predictive values, and accuracy rates were evaluated.

Results:

The sensitivity was 87.1% and specificity was 64.6%. The positive and negative predictive value and accuracy rates were 76.1%, 79.5%, and 77.3%, respectively.

Conclusions:

In our study, the evaluation of thyroid FNAC samples with Bethesda system highly correlated with the results of histopathological diagnosis. However, combination of additional and advanced diagnostic methods such as immunocytochemical studies and molecular pathology techniques enhance the prognostic value of FNAC in patients with atypia of undetermined significance or follicular lesion of undetermined significance, lesions suspicious for malignancy, and suspected follicular neoplasm.

Emerging molecular markers for the prognosis of differentiated thyroid cancer patients

Epithelial thyroid cancers are represented by the differentiated papillary and follicular thyroid carcinomas which, following dedifferentiation, are thought to give rise to the highly aggressive and incurable anaplastic thyroid carcinomas. Although derived from the same cell type, the different thyroid tumors show specific histological features, biological behavior and degree of differentiation as a consequence of different genetic alterations. Over the last few years, our knowledge regarding the molecular alterations underlying thyroid cell malignant transformation and cancer progression has considerably increased; however, the prognosis of differentiated thyroid cancer patients still relies on high-risk clinic-pathological variables. In particular, the actual staging systems provides only a rough prediction for cancer mortality and risk of recurrences, including in each risk group patients with highly different tumor-specific progression, disease-free interval and survival time. In order to improve DTC patient's risk stratification, both the European and the American Thyroid Associations proposed practical guidelines to integrate the actual staging systems with additional clinical features such as the tumor histological variant, the results of post-ablative whole body scan and the serum thyroglobulin levels. Despite that, patients within the same risk group still show a very heterogeneous behavior in terms of disease-free interval. As a consequence, the identification of new prognostic molecular biomarkers able to testify tumor aggressiveness is highly required. Here we'll review recently characterized new molecular markers potentially able to ameliorate the prognosis in DTC patients.

The dosimetric impact of supraclavicular nodal irradiation on the thyroid gland in patients with breast cancer

PURPOSE

The thyroid is not routinely considered an organ at risk in supraclavicular (SC) nodal radiation therapy (RT) for breast cancer. We compared the dosimetric impact of the following 2 RT planning techniques on the thyroid: (1) conventional single anterior field to encompass the SC nodal volume defined clinically; and (2) 3-dimensional conformal radiation therapy (3DCRT) planning to encompass the computed tomography (CT)-contoured SC nodal volume.

METHODS AND MATERIALS

The thyroid, SC nodal volumes, and organs at risk were contoured on the planning CT of 20 patients who received 50 Gy in 2-Gy daily fractions to the breast or chest wall, and SC nodes. Comparisons of dosimetric parameters between the techniques were performed: thyroid, mean and maximum dose, V5, V30, and V50 (percentage of thyroid receiving ≥5 Gy, ≥30 Gy, and ≥50 Gy, respectively); SC nodal volume, homogeneity index (HI, percentage volume receiving 95%-107% of prescribed dose); and maximum doses of spinal cord and brachial plexus. Anatomic characteristics that influenced the dose distributions were investigated.

RESULTS

The 3DCRT planning technique significantly increased all thyroid dosimetric measures (mean dose 17.2 Gy vs 26.7 Gy; maximum dose 48.5 Gy vs 51.9 Gy; V5 45.7% vs 64.9%; V30 33.7% vs 48%; and V50 0.6% vs 26.7%; P < .001). It improved HI for the SC nodal volumes (P < .001) but resulted in higher maximum doses to the spinal cord (6.1 Gy vs 30 Gy) and brachial plexus (43.2 Gy vs 51.4 Gy). The thyroid volume and depth of SC nodes did not influence the thyroid dose distribution. The depth of SC nodes impacted on the HI of SC nodal volumes in the conventional technique (P = .004).

CONCLUSIONS

The 3DCRT planning improved dosimetric coverage of the SC nodal volume but increased thyroid radiation doses. The potential adverse effects of incidental thyroid irradiation should be considered while improving dosimetric coverage in SC nodal irradiation for breast cancer.

Q-elastography in the presurgical diagnosis of thyroid nodules with indeterminate cytology

Quantitative ultrasound (US) elastography (Q-USE), able to evaluate tissue stiffness has been indicated as a new diagnostic tool to differentiate benign from malignant thyroid lesions. Aim of this prospective study, conducted at the Department of Surgical Sciences, of the “Sapienza” University of Rome, was to evaluate the diagnostic accuracy of Q-USE, compared with US parameters, in thyroid nodules with indeterminate cytology (Thy3).The case study included 140 nodules from 140 consecutive patients. Patient’s thyroid nodules were evaluated by Q-USE, measuring the strain ratio (SR) of stiffness between nodular and surrounding normal thyroid tissue, and conventional US parameters prior fine-needle aspiration cytology. Those with Thy3 diagnosis were included in the study. Forty of the nodules analyzed harbored a malignant lesion. Q-USE demonstrated that malignant nodules have a significant higher stiffness with respect to benign one and an optimun SR cut-off value of 2.05 was individuated following ROC analysis. Univariate analysis showed that hypoechogenicity, irregular margins and SR >2.05 associated with malignancy, with an accuracy of 67.2%, 81,0% and 89.8%, respectively. Data were unaffected by nodule size or thyroiditis. These findings were confirmed in multivariate analysis demonstrating a significant association of the SR and the irregular margins with thyroid nodule’s malignancy. In conclusion, we demonstrated the diagnostic utility of Q-USE in the differential diagnosis of thyroid nodules with indeterminate cytology that, if confirmed, could be of major clinical utility in patients’ presurgical selection.

[Thyroid disorders associated with external radiation in children and adolescents]

The effects of ionizing radiation on the thyroid have been studied for several decades, and nuclear accidents are the major source of information about the subject. There is an association of hypothyroidism, hyperthyroidism, thyroid nodules and cancer with radiation, but the threshold dose, mechanism of injury, and some risk factors have not been fully established. Children are more susceptible to thyroid injury caused by radiation and require prolonged follow-up after exposure. This issue is especially relevant nowadays, since a large number of people treated with radiation for childhood cancer survive and may have sequelae. Diagnostic radiology tests also represent a source of exposure to radiation in the pediatric population. In this review, we analyze different clinical and pathological changes, and the mechanisms of thyroid lesions caused by radiotherapy and computed tomography in children and adolescents. It is important to understand these data for prevention, early detection, and treatment of thyroid dysfunction.

Diagnostic accuracy of fine needle aspiration cytology in thyroid lesions

PURPOSE

Evaluation of accuracy of fine needle aspiration cytology (FNAC) in the diagnosis of different thyroid lesions.

PATIENTS AND METHODS

This is a retrospective study of 296 diagnosed cases of thyroid nodules referred to cytology unit, pathology department, NCI, who underwent FNAC for diagnosis. The results were categorized according to the recent Bethesda classification into: insufficient for diagnosis, benign, atypical follicular lesion of undetermined significance, follicular neoplasm, suspicious for malignancy, and malignant sampling. The final histologic diagnosis and/or clinico-radiologic follow-up assessment for non-neoplastic lesions were considered the gold standard.

RESULTS

The study included 296 cases presented with thyroid nodules who underwent diagnostic thyroid FNAC. Female to male ratio was 5.2:1, and the median age was 44years. Ninety-eight cases (33.1%) were diagnosed as benign, 40 cases (13.5%) as follicular lesion of undetermined significance, 49 cases (16.5%) as follicular neoplasm, 30 cases (10.1%) as suspicious for malignancy, 58 cases (19.5%) as malignant, and 21 cases (7.1%) as unsatisfactory. Nodular hyperplasia represented the majority of benign cases (89.8%), while papillary carcinoma was the most frequent malignant lesion (72.4%). Cytologic diagnoses were compared with their corresponding final histologic ones. FNAC achieved a sensitivity of 92.8, a specificity of 94.2%, a positive predictive value of 94.9%, a negative predictive value of 91.8%, a false positive rate of 7.2%, a false negative rate of 5.8%, and a total accuracy of 93.6%.

CONCLUSION

FNA cytology is a sensitive, specific, and accurate initial diagnostic test for the evaluation of patients with thyroid swellings.

Should we use ultrasound features associated with papillary thyroid cancer in diagnosing medullary thyroid cancer?

In thyroid nodule management, ultrasound (US) features, such as hypoechogenicity of the lesion, irregular margins, microcalcifications, and intralesional vascular signal, alone or combined, have to be considered as suggestive for malignancy. Because of the low prevalence of medullary thyroid cancer (MTC), a few papers analyzed US characteristics associated with this cancer in small series, with controversial results. Aim of this study was to evaluate in MTC the US risk factors of thyroid nodule. In this order, a series of nodules histologically proven as MTC and a group of nodules with histology of papillary cancer (PTC) were retrospectively compared with a control group of benign nodule. Fifty percent MTC were solid hypoechoic and 16% showed microcalcifications with significant difference with respect to the benign group (p<0.05 for both parameters), while no significant difference was recorded regarding margins nor nodular vascularization. The presence of at least one US risk feature was almost equal in MTC (58.3%) and controls (55.5%). On the contrary, at least one US risk factor was significantly (p<0.001) more frequent in PTC than in benign group or MTC series. This study showed low frequency of ultrasound features associated to PTC when analyzed in medullary cancer. Because of the poor literature focusing on this topic, and the herein used design, these data contribute to the knowledge about presentation of MTC at US. We advice for further prospective studies on larger series to define the US presentation of this cancer type.

Aryl hydrocarbon receptor interacting protein mutations seem not to associate with familial non-medullary thyroid cancer

BACKGROUND

Over 95% of all thyroid malignancies are non-medullary thyroid carcinomas (NMTC). Familial NMTC are more aggressive and mortality is higher as compared with sporadic carcinomas. Known genetic factors do not explain all familial NMTC. Recently, thyroid disorders have been observed in families with germline mutations in aryl hydrocarbon receptor interacting protein (AIP) but, due to frequent occurrence of these conditions in the population, the significance of this co-occurrence is not clear. AIM, SUBJECTS AND METHODS: To examine whether AIP is involved in familial NMTC, we performed AIP mutation screening in 93 familial NMTC cases. In addition, the AIP status was studied in one follicular thyroid adenoma patient with a known AIP mutation from an additional cohort.

RESULTS

No potentially pathogenic changes were identified, but two likely rare polymorphisms were detected. AIP mutation-positive patient's follicular thyroid adenoma showed no loss of heterozygosity or lack of immunohistochemical AIP staining.

CONCLUSION

Our study indicates that germline AIP mutations are rare or do not exist in familial NMTC.

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.

Association of sonographically detected calcification with thyroid carcinoma

BACKGROUND

Calcification can be detected in both benign and malignant nodules and is often neglected by clinical physicians. The purpose of this study was to investigate the association of thyroid nodule calcification detected on ultrasound with thyroid carcinoma.

METHODS

One hundred seven cases of thyroid carcinoma and 215 cases of benign thyroid nodules were selected from the records of inpatients of our hospital who had high-resolution ultrasonography preoperatively and pathologic diagnosis postoperatively between 2001 and 2004. The case numbers and percentage of calcification, fine stippled psammomatous (FSP), and non-FSP calcification in benign nodules and thyroid carcinoma, sex, and age groups (<45 years and >or=45 years) were retrospectively reviewed. Statistical analysis was performed using chi-square test and odds ratio. Sensitivity and specificity of calcification and FSP calcification on ultrasonography were also calculated.

RESULTS

The incidence of calcification, non-FSP calcification, and FSP calcification were significantly higher in thyroid carcinoma than in the benign group (p < .001, p = .03, and p < .001, respectively). However, FSP calcification was more significant than the non-FSP calcification (p = .001) for predicting thyroid cancer. The incidence of non-FSP calcification and FSP calcification did not differ significantly between the sexes (p = .50 and p = .83, respectively). The relative risk of malignancy incidence was significantly higher in those younger than 45 years old with FSP calcification (p < .001). The incidence of non-FSP calcification was significantly higher in the older group (p = .03). The sensitivity of calcification and FSP calcification for the detection of malignancy was 63.55% and 24.30%, respectively; the specificity was 69.77% and 96.77%, respectively.

CONCLUSIONS

The detection of calcification on ultrasonography should increase the clinical index of suspicion for thyroid carcinoma and alert the physician. FSP calcification is valuable and has a very high specificity for predicting thyroid carcinoma, particularly for those younger than 45 years old or with calcified regional lymph nodes. To increase the sensitivity for the diagnosis of thyroid carcinoma, tests such as fine-needle aspiration cytology should also be performed. The use of these modalities could result in earlier detection of thyroid carcinoma. The use of ultrasound to detect calcification and FSP calcification is as efficient as thyroid papillary macrocarcinoma in predicting microcarcinoma.

Telomerase activity in “suspicious” thyroid cytology

BACKGROUND

Telomerase activity (TA) has been detected in most malignant neoplasms, including thyroid carcinomas. The authors studied the utility of TA detection as an ancillary tool to thyroid fine-needle aspiration (FNA) for patients with nonconclusive cytologic diagnoses.

METHODS

Material obtained by FNA from palpable thyroid nodules in 167 consecutive patients was processed for conventional cytologic studies and simultaneously for TA study. Another 8 patients were excluded from TA because of the presence of lymphocytes. All patients with negative results cases were followed for > 1 year, and those who had tumors that were suspicious or positive by FNA or TA underwent resection for pathologic study of nodules. TA was analyzed by telomere repeat amplification protocol-polymerase chain reaction analysis.

RESULTS

After excluding 20 patients because of insufficient material for cytologic study, 120 patients had negative results for malignant cells in cytology material, and the remaining 27 patients had results that were either suspicious (n = 21 patients) or positive (n = 6 patients). Histopathologic confirmation was obtained in 23 patients, including 18 with suspicious cytology (1 with scanty material) and 5 with positive FNA. The histopathologic diagnoses were nodular hyperplasia in 5 patients, follicular adenoma in 3 patients, papillary carcinoma in 11 patients, follicular carcinoma in 1 patient, medullary carcinoma in 2 patients, and lymphoma in 1 patient. TA was detected in 6 of 18 histologically confirmed thyroid neoplasms (1 of 3 follicular adenomas, 3 of 11 papillary carcinomas, 0 of 1 follicular carcinoma, 1 of 2 medullary carcinomas, and 1 of 1 lymphoma), including 1 neoplasm with scanty atypical cells.

CONCLUSIONS

The detection of TA helped to confirm neoplasia in 6 of 23 suspicious thyroid nodules. Although it was less sensitive than FNA, TA specificity was 100% for neoplasia and 87.5% for malignancy. The sensitivity of thyroid FNA increased with the use of TA detection when cytology was nonconclusive for malignancy.

The thyroid incidentaloma: an increasingly frequent consequence of radiologic imaging

Incidentally discovered thyroid lesions have become increasingly common with the development and more frequent utilization of highly sensitive imaging modalities throughout the clinical practice of medicine. Determining the most appropriate management of these "incidentalomas" has presented a significant challenge to both endocrinologists and endocrine surgeons. Algorithms with which to accurately identify those malignant lesions hidden amongst the overwhelming majority of those which are benign have not yet been established. This article will review the existing literature concerning the subject of thyroid incidentalomas and recommend a methodical approach to evaluating these patients such that the greatest number of malignancies may be detected while subjecting the fewest patients with benign lesions to unnecessary testing. Additionally, the role of the radiologist as an integral part of the multidisciplinary team of surgeons, endocrinologists, and cytologists working together to identify those patients with the highest risk of malignancy will be explored.

Expression of matrix metalloproteinases and their specific inhibitors in normal and different human thyroid tumor cell lines

In the present study we investigated, by means of zymography and reverse transcription-polymerase chain reaction (RT-PCR), the expression of different matrix metalloproteinases (MMPs) and of the specific tissue inhibitor of metalloproteinases [TIMPs] in human cell lines derived from normal thyrocytes (HTU5), follicular adenoma (HTU42), and follicular (FTC-133), papillary (B-CPAP), and anaplastic (CAL-62, 8305C) thyroid carcinomas. We demonstrated that normal thyrocytes constitutively express MMP-1, MMP-2, MMP-10, MMP-14, and TIMP-1, TIMP-2, TIMP-3, and TIMP-4, and this pattern of expression is profoundly modified in all thyroid tumor-derived cell lines. Analysis of the gelatinolytic activity in the different cell supernatants showed that the expressions of MMP-2 and MMP-9 are, respectively, increased or induced in all the neoplastic cell lines, except in CAL-62. Caseinolytic activity was found only in the supernatants of the 8305C and B-CPAP cells. Using RTPCR analysis we detected an increased expression of MMP-1 in cell lines derived from papillary and from one (8305C) of the two anaplastic carcinomas. MMP-13 mRNA was expressed only in the 8305C, FTC-133, and BCPAP cells. Among stromelysins, MMP-3 mRNA could not be detected in any cell line, while MMP-10 mRNA was expressed in all of them, although at variable levels. MMP-11 mRNA was absent in normal and follicular adenoma derived thyrocytes and induced in all carcinoma cell types. The expression of MMP-14 (MT1-MMP) mRNA was found significantly increased in all thyroid tumor cell lines with respect to HTU5 and HTU42 cells. The expression of TIMP-1 and TIMP-2 mRNAs was maintained in all cell lines tested, while that of TIMP-3 was lost in both anaplastic carcinoma cell lines and that of TIMP-4 was absent in the CAL-62. In conclusion, our data demonstrated a differential expression of MMPs and TIMPs in different thyroid tumor cell types with respect to normal thyrocytes. In particular, the induction of MMP-11 in all thyroid-derived carcinoma cell lines studied and of MMP-13 in all but one may represent, if confirmed in other thyroid tumor-derived cell lines and in thyroid tumor tissues, a new marker of thyrocyte transformation.

Management of thyroid incidentalomas

The discovery of a thyroid incidentaloma warrants a systematic approach for those nodules most likely to be cancerous. An optimal management strategy for thyroid incidentalomas should be guided by four questions: (1) Does the incidentally detected thyroid nodule put the patient at risk for an adverse outcome; (2) Can those individuals with malignant thyroid nodules be identified; (3) Is the treatment of thyroid malignancy more effective in presymptomatic patients; and (4) Do the beneficial effects of presymptomatic detection and treatment in these patients justify the costs incurred Physicians caring for patients with thyroid disease should participate in data acquisition in national databases and properly randomized studies, to address the optimal management strategy in the treatment of incidentally-detected thyroid nodules.

Radiotherapy-induced thyroid disorders

Despite their specific functional consequences, radiotherapy-induced thyroid abnormalities remain under-estimated and underreported. These sequelae may include primary or central hypothyroidism, thyroiditis, Graves' disease, euthyroid Graves' ophthalmopathy, benign adenomas, multinodular goitre and radiation-induced thyroid carcinoma. Primary hypothyroidism, the most common radiation-induced thyroid dysfunction, affects 20-30% of patients administered following curative radiotherapy to the neck region, with approximately half of the events occurring within the first 5 years after therapy. The relative risk of radiation-induced cancer (mainly well-differentiated tumours) is 15-53-fold higher than in non-irradiated population. The aetiology of radiation-induced thyroid injury includes vascular damage, parenchymal cell damage and auto-immune reactions. Total radiotherapy dose, irradiated volume of the thyroid gland, and the extent of prior thyroid resection are among the most important factors associated with the risk of hypothyroidism. The contribution of other treatment modalities (chemotherapy, endocrine therapy) as well as patient- and tumour-related factors is less clear. Reduction in radiation dose to the thyroid gland and hypothalamic/pituitary complex should be attempted whenever possible. New radiotherapy techniques, such as stereotactic radiosurgery, three-dimensional conformal irradiation, intensity modulated radiotherapy and proton therapy allow generally better dose distribution with lower dose to the non-target organs. The diagnostic approach to thyroid radiation injury includes baseline thyroid function assays in all patients undergoing thyroid or parasellar irradiation. Recommended follow-up procedures include at least annual evaluation with a history for symptoms of thyroid dysfunction, clinical examination, and measurement of thyroid hormones and thyrotropin. Management of overt hypothyroidism is based on hormone replacement therapy. Thyroid hormone therapy is also recommended in cases of subclinical hypothyroidism. Treatment of other radiation-induced thyroid disorders (thyroiditis, Graves' disease, thyroid cancer) is similar to that employed in spontaneously occurring conditions. Further improvements in radiotherapy techniques and progress in endocrine diagnostics and therapy may allow better prevention and management of radiation-related thyroid injury.

Fine-needle aspiration of the thyroid and correlation with histopathology in a contemporary series of 240 patients

BACKGROUND

False-positive, false-negative, and indeterminate fine-needle aspiration (FNA) biopsy results complicate the management of patients with thyroid nodules.

METHODS

Thyroid FNA results from 240 consecutive patients (seen 1991 to 2002) were categorized into four groups: positive for malignancy, negative for malignancy, indeterminate for malignancy, and nondiagnostic. Indeterminate results included follicular neoplasm, Hürthle cell neoplasm, and suspicious for papillary carcinoma. The FNA results were compared with histopathologic analysis after thyroidectomy.

RESULTS

The FNA results were 76 (32%) positive for malignancy, 53 (22%) negative for malignancy, 100 (42%) indeterminate for malignancy, and 11 (5%) nondiagnostic. There were 3 (4%) false-positive and 2 (4%) false-negative FNA results. Among the 100 indeterminate FNA results, carcinoma was found in 11 (15%) of 73 follicular neoplasms, 2 (20%) of 10 Hürthle cell neoplasms, and 14 (82%) of 17 suspicious for papillary carcinoma. For the 73 patients with follicular neoplasms, nodule diameter >2 cm was associated with an increased risk of malignancy (P <0.03).

CONCLUSIONS

False-negative FNA results are uncommon, supporting the practice of observation in most of these patients. Among those with indeterminate biopsy results, high-risk subgroups include patients with FNA results suspicious for papillary carcinoma and follicular neoplasms >2 cm.