Thyroid Fine Needle Aspiration Cytology Research Articles

THE LEARNING CURVE AND PERFORMANCE OF A NEWLY ESTABLISHED THYROID FINE-NEEDLE ASPIRATION CENTER.

Thyroid fine-needle aspiration (FNA) cytology is the best tool for preoperative diagnosis of thyroid carcinoma; however, its learning curve is poorly described. Our aim was to assess the learning curve of a new thyroid FNA center involving unexperienced operator and pathologist. We retrieved from our tertiary endocrinology center database all thyroid FNA procedures done by a single operator (endocrinologist with no experience in FNA) between 2018 and 2021. Cytology was assessed by two pathologists with limited or no experience in thyroid cytology. We also got the corresponding sex, age, nodule diameter, EU-TIRADS score, Bethesda category and final pathology report. There were 1872 FNA in 1618 patients. Proportion of Bethesda 1 nodules decreased significantly (p for trend=0.003) from 17% in the first 100 FNA procedures to 4% in the 401-500 group of procedures, and remained constant between 9% and 4% (p for trend=NS) for the rest of the study. Proportion of Bethesda 2 rose steady from 26% in the first 100 nodules to 80.1% in the last 241 nodules (p for trend<0.001). Indeterminate lesions (Bethesda 3 and 4) decreased significantly (p for trend=0.001) from 16% and 35% in the first 100 nodules to 2.5% and 5.8% in the last 241 lesions. Proportions of Bethesda 5+6 categories varied non-significantly over time. There were no time trends in the malignancy rate of surgically removed nodules. At least 300 procedures are needed to reach the standard performance. A steadily state for the whole center is obtained after about 500 procedures.

Utility of White Blood Cell Diluting Fluid (Turk’s Fluid) in Evaluation of Haemorrhagic Thyroid Cytology Smears in a Tertiary Care Centre- A Novel Study

Introduction: Fine Needle Aspiration Cytology (FNAC) has been one of the safest and accurate diagnostic technique in diagnosing thyroid lesions. But due to the vascularity of thyroid tissue, diagnostic cells get entrapped in blood clot unless rapid smearing is done.This results in repeat FNAC which is inconvenient to the patient as well as time consuming to pathologist. Therefore, an alternative is required to avoid repeat FNAC procedure. Aim: To evaluate the role of Turk's fluid in haemorrhagic thyroid FNAC smears in comparison to conventional haemorrhagic smears. Materials and Methods: The present study was a prospective observational study, which was conducted for the period of six months (March-August 2021). A total of 30 cases were included in the study. FNA sampling was done on patients with thyroid swelling. After the needling was done on the swelling, four smears. One was stained using (H &amp; E). Rest of all the smears were stained by Conventional Giemsa (CG) method. One of these CG stained smears was immediately treated with Turk's fluid for 10-20 seconds. The CG stained smears were compared with the Turk's fluid Treated Giemsa (TTG) smears and evaluated for retention of Red Blood Cells (RBCs), visibility of nuclear and cytoplasmic details of thyroid follicular cells. Results: A total of 30 cases were included in the study. The retention of RBC was lesser in TTG compared to CG which was statistically significant (p-value&lt;0.05). The visibility of cytoplasmic and nuclear morphology on TTG was better than that of CG which was statistically significant (p-value&lt;0.05). Conclusion: TTG smears improves visibility of cytomorphological features by reducing background RBCs and hence avoids repeat FNAC.

Malignancy Rates in Thyroid Nodules Classified as Bethesda III and IV; Correlating Fine Needle Aspiration Cytology with Histopathology.

Fine needle aspiration cytology (FNAC) is an integral part in the diagnostic work up of thyroid nodules. FNAC reports are based on Bethesda system for thyroid cytopathology which is one of the most commonly used systems worldwide. The main objective of the present study was to evaluate the malignancy rates in Bethesda category III and IV thyroid nodules over a six-year period. 642 thyroid FNAC were performed over a six-year period. The medical records of all these patients were reviewed using electronic patient records. Cases reported to have Bethesda category III and IV were included in the study. Data for these patients were reviewed to determine the relationship between these categories and thyroid cancer. There were 41 cases of category III of which 19 underwent surgery and the malignancy rates were found to be 26.3%. Category IV consisted of 50 cases of which 45 underwent surgery and the malignancy rates were 26.6%. The results from our study are similar to findings in larger multicentric studies which found that malignancy rates for Bethesda category III and IV were 10-30% and 25-40%, respectively.

Fine needle aspiration cytology of primary thyroid non-hodgkins lymphoma: Experience from a tertiary care center of North India.

Twelve cases of Primary Thyroid Non-Hodgkin's Lymphoma (PT-NHL) were retrieved from the records suspected or diagnosed as NHL on fine needle aspiration cytology (FNAC) over a period of nine years from 2010-2018. During this period 5236 patients underwent thyroid FNAC;of these 685 cases were diagnosed under Bethesda Caregory V and VI. Thyroid NHL constituted 0.23 % of all thyroid FNA (12/5236 cases)and 1.7% (12/685) of all thyroid malignancies. Patients ranged in age from 40-61 years with Female:Male 7:5. All patients presented with thyroid enlargement (5-14 cms), and were of two months to five years duration. Patients had history of tobacco intake (smoking/chewing)in nine cases (75%). Thyroid function tests showed hypothyroidism in four (33%), positive antithyroid antibodies in three (25%) and; two cases(16.7%) were known cases of Hashimotos thyroiditis with follow up. Eight cases (66.7%) had monomorphic large cell morphology,other four had mostly intermediate cell types (33.3%). A panel of immunocyto/ histochemistry (ICC/ IHC) showed CD 19 and CD 20 positivity in all cases;sixof these could be correlated on Flow cytometry (FC) with expression of FMC7, CD20, CD19 with kappa light chain restriction (5) and Lambda (1). FC findings corroborated completely with IHC on biopsy sections. The final diagnosis were Diffuse large B cell Lymphoma (DLBCL,8) and MALT- Lymphoma(4). The follow up was available in DLBCL (4) and MALT- Lymphoma (1). CHOP therapy were given in all patients followed by radiotherapy in DLBCL; one patient of DLBCL died following pulmonary complications, rest are well and alive on follow-up. PT-NHL is rare in India. DLBCL is the commonest histological type reported. In the present study, tobacco exposure has shown strong association. Combined FNAC-FC provide definitive diagnosis and thus can replace histopathology reducing turn around time. FNAC -FC provides a definitive diagnosis and thus can reduce turnaround time.

Appraisal of cytohistomorphology of papillary carcinoma thyroid and its variants with evaluation of discrepant cases

Background: Papillary carcinoma thyroid is the most commonly occurring thyroid neoplasm which can be diagnosed by its characteristic cytological features by fine-needle aspiration procedure. Due too few limitations in fine-needle aspiration cytology (FNAC) technique, there are false-positive and false-negative diagnoses in papillary carcinoma thyroid lesions. Aim: In our study, we would like to evaluate the accuracy of thyroid FNAC and to determine the reasons for cytopathological discrepancies. Materials and Methods: Two hundred and twenty-three cases were collected from archives of our Department of Pathology. Slides were retrieved for which cytohistopathology correlation differed and reviewed. Statistical analysis for False positive/ negative rates, positive predictive value, sensitivity and specificity were done. Results: For 170 cases, cytohistopathology correlation, 27 cases were discordant which accounted for 15.2% of false-negative rates. 87% sensitivity, 96.6% positive predictive value and 10.6% false positive were calculated. Conclusion: FNAC is a reliable screening procedure in spite of having few pitfalls. Awareness of these pitfalls, while reporting by cytopathologist can minimize false-positive and false-negative reporting on thyroid lesions.

Reproducibility of Cytomorphological Diagnosis and Assessment of Risk of Malignancy of Thyroid Nodules Based on the Bethesda System for Reporting Thyroid Cytopathology: A Tertiary Cancer Center Perspective.

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was introduced for unifying the terminology and morphologic criteria along with the corresponding risk of malignancy, leading to more consistent management approaches. The aim of this study was to study the utility and reproducibility of TBSRTC in reporting thyroid cytology in a referral cancer center. The fine-needle aspiration (FNA) of all thyroid nodules were included for a period of 5 years, from January 2016 to December 2021, in this cancer center. They were retrospectively reviewed and recategorized according to TBSRTC by two experienced pathologists. Cytohistopathological correlation was done for the cases which underwent surgical resection. 522 fine-needle aspiration cytology (FNAC) of thyroid swellings were evaluated and categorized according to TBSRTC. There was agreement in the cytological diagnosis of 512 cases, of which 260 (50.78%) were benign lesions, 189 (36.91%) were malignant, 5 (0.97%) were unsatisfactory/nondiagnostic, 41 (8.01%) were follicular neoplasm/suspicious for neoplasm, 13 (2.53%) were suspicious for malignancy, and 4 (0.78%) cases were reported as atypia of undetermined significance. Two cytopathologists were in agreement in 512 cases (98%) of cases. Almost complete concordance was noted in the malignant (99%) and benign categories (98%). Disagreement was seen in 10 cases. Histological follow-up was available in 201 cases with an overall malignancy rate of 62.68% (126/201). TBSRTC proved to be a very simple and effective reporting system for thyroid FNAC, especially in the setting of a cancer center. This enables proper triaging of cases with thyroid masses into those who require surgical intervention and those who can avoid it, thereby preventing unnecessary morbidity.

Fine-needle aspiration cytopathology correlation study of thyroid nodule with the postoperative histopathological reporting in a rural medical setup

Background: Fine-needle aspiration cytology (FNAC) is the examination of cells that are obtained through a fine needle under vacuum. Due to the superior diagnostic reliability and cost-effectiveness of FNAC, American thyroid association had setup some guidelines stating that FNAC must be used as a diagnostic test initially before the ultrasonography and thyroid scintigraphy. This present study was undertaken to categorize and correlate all the thyroid FNAC samples according to the Bethesda system and for assessing the efficacy of the Bethesda reporting system in the preoperative evaluation of thyroid lesions. The major aim of study is to identify the nodules which require surgery and those benign nodules that can be observed clinically, thereby reducing the overall rate of thyroidectomy among patients with benign disorders. Materials and Methods: The present prospective study was conducted among 428 patients with thyroid lesions at a tertiary care rural medical set up. All the specimens were fixed in 10% formalin, and detailed gross examination was done. 3–10 tissue bits were selected from representative areas and all the bits were processed and stained with H and E stain. Cytological diagnoses were correlated with histopathology and the efficacy of The Bethesda System for Reporting Thyroid Cytopathology for reporting FNAC was estimated. Discussion: Out of 428 patients with thyroid lesions, 96 cases of histopathological specimens were collected. The histopathology lesions were divided into benign nonneoplastic, benign neoplastic, and malignant to study the gender, age group affected with these lesions and to calculate the association of malignancy with gender and age. The result showed that diagnostic tests are not significantly different with respect to sensitivity. Hence, FNAC is a reliable test for histopathology in diagnosis of thyroid lesions. In the present study, although the malignancy rate was higher among males, no association of gender and malignancy was not significant (P > 0.05). Conclusion: The Bethesda standardized system for reporting cytopathology improved the communication between pathologists and clinician promoting an interlaboratory agreement.

Pre tibial myxedema associated with hypothyroid Hashimioto’s thyroiditis

Pretibial myxedema (PTM) is an infiltrative dermopathy due to accumulation of glycosaminoglycans in the dermis and sub cutis. It is commonly associated with Grave’s disease. However, it is infrequently associated with Hashimoto’s thyroiditis and primary hypothyroidism. It often presents as an asymptomatic diffuse non pitting edema, nodule or plaque involving both pretibial areas. Pretibial myxedema may undergo partial or complete remission and is primarily a cosmetic concern for the patient. Apart from treatment of the primary thyroid abnormality, topical or intralesional steroids remain the mainstay of treatment. We report a case of a 72-year-old lady who presented with non pitting edema on both legs. Her thyroid function tests were suggestive of hypothyroidism and thyroid auto antibody profile, ultrasonography and fine needle aspiration cytology favored Hashimoto’s thyroiditis. Histopathology of the pretibial skin was in consistent with pretibial myxedema. A paradox of pretibial myxedema in a patient with Hashimoto’s thyroiditis is a rare clinical entity.

Role of Fine Needle Aspiration Cytology (FNAC) in Surgical Intervention of Thyroid Lesions: in Correlation with Thyroid Hormone Profile

Abstract: Background: Fine needle aspiration cytology (FNAC) of the Thyroid is over half a century old and has been shown to be superior to clinical, radionucleotide or thyroid ultrasound assessment alone. It is the most accurate, cost-effective, and simplest screening test for rapid diagnosis of thyroid nodules. Evaluation of both cytomorphological pattern and thyroid hormone profile aids in early detection of various thyroid diseases there by reducing surgical intervention. Aims and Objectives: To correlate role of thyroid hormone profile (T3, T4 and TSH) with cytology results, in various thyroid disorders like diffuse nontoxic goiter, diagnosis of solitary/dominant thyroid nodule and thyroid malignancy. To evaluate the clinical correlation with Euthyroid, Hypo and Hyperthyroid picture in various disorders. To calculate the percentage of surgical intervention for various thyroid disorders in view of thyroid profile in correlation with FNAC findings. Material and methods: All patients who underwent thyroid FNAC from July 2017 to June 2018 have been included in the study only if Thyroid profile has been done. The various lesions have been categorised as Euthyroid, Hypothyroid and Hyperthyroid as per the hormone analysis results. The FNAC findings have been reported as per the Bethesda System and classified as per the latest WHO guidelines. Results: predominantly affected gender was females (91.25%), most common affected age group was 41-50 years (30%), 88.75% were euthyroid patients, most common benign lesion on FNAC was nodular goiter (33.75%), malignant lesion was papillary thyroid carcinoma (18.75%), thyroid profile in various thyroid lesions were euthyroid.

Comparison between sensitivity and specificity of thyroid elastography and fine needle aspiration cytology in differentiating the nature of thyroid nodules

Abstract Background Nodular goiter is the most frequent disease of the thyroid gland, it may affect up to 50% of adults and elderly people, Although malignancy only occurs in about 5% of thyroid nodules, the detection rate of papillary thyroid carcinoma has increased consistently both in women and men and in all ethnic groups Thus, the task of differentiating malignant from benign nodules is necessary. Ultrasound elastography (USE) is a non-invasive, completely painless for the patient and can be easily performed even during routine ultrasound examinations. It assesses lesion stiffness by evaluating tissue distortion in response to stress. Objective Study the role of strain elastography in the characterization of benign and malignant nature of the thyroid nodule Compare the sensitivity and specificity of ultrasound elastography (USE) and fineneedle aspiration cytology (FNAC) as preoperative predictor of malignancy in order to decrease the need for FNAC. Cytology report is the gold standard/ histopathology report if available. Patients and Methods Type of Study: Cross-sectional study. Study Setting: The study was conducted at Ain Shams University Hospitals. Patients: 32 patients, 16 benign, and 16 malignant Patients with thyroid nodules proven by FNAC referred to Ain Shams University Radiology Unit. Results After analysis of strain index (SI) and the elasto score with FNAC we found the cut of point for thyroid malignancy was &amp;gt;1.4 and &amp;gt;2 respectively. The sensitivity and specificity of strain index (SI) for thyroid malignancy diagnosis were 100% and 75%, respectively. The positive and negative predictive values were 80% and 100%, respectively its p-value was 0.000, being a highly significant test.The US-elastography score’s sensitivity and specificity for thyroid malignancy diagnosis both were 81.25%. The positive and negative predictive values both were 81.2%, its pvalue was 0.000, being a highly significant test. After the Postoperative histopathology which is done to only ten patients of the 32 patients with available results (31.3%), 4 of them were benign (12.5%), and six were malignant (18.8%), We conclude that the Elasto ratio is the most sensitive diagnostic test with NPP (negative predictive value) of 100 % being the best screening test while the FNAC is the most specific test with PPV(positive predictive value) of 100 % being the best diagnostic test while the elasto score’s p-value was 0.065, being a a non-significant test. Despite this good diagnostic performance, USE with SI assessment not yet meets all requirements for an optimal diagnostic tool as its specificity is only 75%, while that of FNAC is almost reaching 100% compared to the postoperative histopathology Conclusion Strain elastography was highlighted as a good tool for pre-operative differentiation of benign from malignant lesions showing high sensitivity and moderate specificity compared to other studies, thus further decreasing thyroid biopsies and surgeries. The most reliable tool in our study was the elasto ratio having the highest sensitivity. Ultrasound examination in combination with elastography is a well-tolerated, non-invasive, and cost-effective diagnostic tool in the pre-operative assessment of thyroid nodules, which is able to enhance the accuracy of assessing the risk of malignancy in thyroid nodules and for selecting nodules for FNAC, thus can be used to postpone the FNAC to decrease the amount of the unnecessary FNAC.

TERT Promoter Mutation in Indeterminate Thyroid Fine Needle Aspiration Cytology: An Indicator of Unfavorable Disease?

TERT Promoter Mutation in Indeterminate Thyroid Fine Needle Aspiration Cytology: An Indicator of Unfavorable Disease?

Diagnostic accuracy of fine needle aspiration cytology in neoplasms of solitary nodule in thyroid gland: a retrospective study

Background: Common endocrine disorders like thyroid nodule may represent thyroid neoplasm either benign or malignant and are important to be diagnosed as they may progress and lead to thyroid dysfunction. Fine needle aspiration cytology (FNAC) has emerged as an economic, rapid, effective, simple and accurate strategy for diagnosing neoplastic thyroid nodules. The basic aim of the current investigation was to evaluate the diagnostic accuracy of FNAC in neoplasms of solitary thyroid nodules.Methods: Current investigation was a retrospective diagnostic test evaluation study conducted on 60 patients who underwent total thyroidectomy for solitary nodule for a duration of one year. Routine blood investigation, thyroid function test, FNAC, chest X-ray, indirect laryngoscopy and ultrasound scanning of neck were done for all the patients. Collected data was coded and entered in excel sheets and was statistically analyzed using SPSS.Results: Mean age of the participating patients was 45.51±7.2 years and age range was 24 to 68 years. Female patients were observed to be more than male patients. In majority of the patients duration of nodule was less than or equal to one to three years. Maximum number of patients underwent either total or hemi thyroidectomy. FNAC diagnostic findings revealed patients with NCG, FN, LT, PC and MC. The results of FNAC findings resembled and were supported by HPR findings.Conclusions: Current investigation findings revealed that fine needle aspiration cytology can be considered as potential, accurate, rapid and efficient diagnostic technique for rapid primary investigation of neoplasms of solitary nodules in thyroid gland.

Cytomorphological Profile of Thyroid Lesions on Fine Needle Aspiration Cytology

Background and Objectives: Fine needle aspiration cytology (FNAC) of thyroid offers an alternative, as an immediate, preliminary procedure associated with low cost, little trauma and complications. Being superficial and easily accessible it is an ideal organ for FNAC. It is useful in diagnosis of inflammatory, infectious and neoplastic conditions. The aim of this study was to evaluate the cytomorphological profile of thyroid lesions on FNAC with application of Bethesda system for reporting and perform cyto-histopathology correlation whenever possible with regards to age and sex distribution. Methodology: This two-year prospective study was conducted in the Cytology section of Pathology Department &amp; included 243 cases of thyroid gland enlargement. The detailed history of the patient including age, sex, presenting symptoms and duration of thyroid gland enlargement along with any other significant findings was note. FNAC was performed as per the protocol using a 23-gauge needle and smears stained using Haematoxylin &amp; Eosin (H&amp;E) and Papanicolaou stain, while air-dried smears were stained with Giemsa stain. Results: The study period included a total of 243 FNACs of thyroid enlargement. The age of patients ranged from 10 to 80 years with male to female ratio of 1.4. The diagnosis on FNAC was as follows Colloid Goitre (54.7 %), Lymphocytic Thyroiditis (9.54%), Follicular Neoplasm (7.05%), Hashimoto Thyroiditis (5.80 %), Benign Thyroid Lesions (3.31%) and Multinodular Goitre (2.90%). Conclusion: Thyroid fine needle aspiration cytology has proven to be a first line tool to evaluate the thyroid lesions because of its cost effectiveness and high patient acceptance. Fine needle aspiration cytology is highly successful in triaging patients with thyroid nodules into operative and non-operative groups and enables surgeons to take an early decision regarding mode of treatment. The Bethesda system for reporting of thyroid lesions aims at standardization of reports. It makes the cytology report unambiguous and clinically relevant. Keywords: Fine needle aspiration cytology, thyroid lesions.

Correlation between thyroid fine needle aspiration cytology and post-operative histology: A 10-year single-centre experience

Correlation between thyroid fine needle aspiration cytology and post-operative histology: A 10-year single-centre experience

Subclassification of the Bethesda Category III (AUS/FLUS): A study of thyroid FNA cytology based on ThinPrep slides from the National Cancer Center in China.

The atypia of an undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category in the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is a heterogeneous category, which includes various cell patterns. The subclassification of AUS/FLUS was suggested in the 2017 TBSRTC. However, the risk of malignancy (ROM) associated with different subgroups remains unresolved. Herein, AUS/FLUS aspirates were subclassified, from which the ROM of each subgroup was determined. All cases undergoing fine-needle aspiration (FNA) from July 2013 to December 2018 were reviewed. Of 12,913 thyroid FNAs, 1053 (8.2%) were AUS/FLUS. The slides of 222 patients with AUS/FLUS with surgical follow-up were reviewed and subclassified according to the recommendations of the 2017 TBSRTC. There were 195 aspirates consistently diagnosed as AUS/FLUS and subclassified as cytologic atypia 1 (AUS-C1); cytologic atypia 2 (AUS-C2); architectural atypia (AUS-A); cytologic and architectural atypia (AUS-C&A); Hürthle cell aspirates (AUS-H); atypia, not otherwise specified (AUS-NOS); and atypical lymphoid cells, rule out lymphoma (AUS-L). Malignancy was identified in 83.3% (185 of 222) of the AUS/FLUS nodules. The AUS-C1 group was the most common (62.1%), followed by the AUS-C&A (12.8%), AUS-C2 (10.8%), AUS-H (6.7%), AUS-NOS (5.6%), AUS-L (1.5%), and AUS-A (0.5%) groups. AUS-C1 had the highest ROM (92.6%) among the groups and varied significantly from that of the AUS-C&A (P = .171), AUS-C2 (P = .001), AUS-H (P = .001), and AUS-NOS (P < .001) groups. As a heterogeneous category of TBSRTC, the ROM for AUS/FLUS varies greatly among medical centers. Subclassification of AUS/FLUS might be helpful in identifying nodules with a high ROM in this category and improving the management of such nodules.

Thyroid FNA terminology: The case for a single unified international system for thyroid FNA reporting.

The use of reporting terminologies for thyroid FNA cytology enables standardisation and international alignment of the reporting of thyroid cytology results, which is essential. There are currently three major internationally recognised systems: Bethesda (TBS), UK RCPath (Thy), and Italian (TIR). A fourth terminology system used in Japan has identical categories to TBS but with different nomenclature. The aim of this review is to discuss the strengths and weaknesses of the TBS, UK RCPath, and TIR systems, and to make the case for international terminology harmonisation and standardisation.

How limited molecular testing can also offer diagnostic and prognostic evaluation of thyroid nodules processed with liquid-based cytology: Role of TERT promoter and BRAF V600E mutation analysis.

Mutational analysis contributes to the diagnosis and prognosis of thyroid nodules analyzed with fine-needle aspiration cytology (FNAC). Although several advanced molecular tests based on multiple molecular markers are available for clinical use and have increased their impact on clinical management of patients, they are not widely available. Among them is BRAF V600E, one of the most studied mutations. Other genetic alterations, such as TERT promoter mutations, may coexist in thyroid carcinomas. Previous studies have demonstrated that this duet might be involved in the aggressiveness of thyroid cancer, although its prognostic value related to mortality remains undefined. The detection of such genetic alterations in thyroid liquid-based cytology (LBC) thus may assist with patient management. From January 2013 to June 2014, 356 thyroid FNAC samples were processed by LBC, including 174 surgical follow-up samples. BRAF V600E and TERT mutation analyses were performed on both LBC and histopathology. The study included 119 samples categorized as atypia of undetermined significance, 42 categorized as follicular neoplasms, 61 categorized as suspicious for malignancy, and 34 categorized as positive for malignancy. BRAF V600E mutation was detected in 10.4% of all cases, whereas TERT promoter mutations were identified in 1.1%. TERT-mutated cases belonged to the positive for malignancy category, with a histologic diagnosis of tall cell variant of papillary thyroid carcinoma. These genetic alterations correlated with lymph node metastases (P = .0349) and higher disease stage. BRAF V600E and TERT analysis can be performed on LBC. TERT mutations are rarely identified in well differentiated thyroid carcinoma but are associated with higher stage. Although a larger molecular panel may offer more information, analyzing these few point mutations is still likely to be useful for managing potentially more aggressive thyroid carcinomas.

Is it possible to eliminate the number of inappropriate thyroid surgeries combining scintigraphy and cytology?

Objective: Although fine needle aspiration cytology (FNAC) is the most reliable, safe and accurate method for the clinical management of abnormal thyroid nodules, 5%-15% of cases lead to indeterminate diagnoses and surgery is the recommended practice for them as they may be malignant. Nevertheless, the majority of cases with indeterminate cytology are benign, so the risk of unnecessary surgery is significant. In our study we combined FNAC and scintigraphy in order to reduce the number of inappropriate surgeries. Subjects and Methods: From 219 patients with thyroid fine needle aspiration cytology 33(9 males and 24 females) aged 18-73 years, had indeterminate FNAC diagnoses and were referred for scintigraphy. Surgery was performed in all cases. The results of FNAC, scintigraphy and histology were collected and compared. Results: From 33 cases with indeterminate cytology 32 had a benign histological diagnosis and only one was malignant (follicular Ca). That case had a positive scan. All cases with negative thyroid scans (29/33) were benign. False positive scans were 3, whereas one scan was true positive with final diagnosis follicular carcinoma. Conclusion: This study showed that combining the FNAC with the thyroid scintigraphy in cases of thyroid nodules with indeterminate cytology it is possible to reduce the number of inappropriate surgeries from 32 to 3.

Malignancy Risk in 18F-FDG-Avid Thyroid Incidentalomas: Controversies and Limitations

Introduction: The prevalence of malignancy in thyroid incidentalomas (TI) discovered on 18F-FDG-PET or PET/CT varies between 0% and 63.6%. The pooled malignancy rate according to three systematic reviews is 33-35%. The 2015 American Thyroid Association (ATA) guidelines recommend that such nodules, when one centimeter or larger in size, should undergo further investigation with thyroid ultrasound (US) and fine-needle aspiration (FNA) cytology. Objectives: The objective of our study was to determine the rate of malignancy amongst TI discovered incidentally on 18F-FDG-PET or PET/CT, examine their clinicopathologic characteristics, and assess the usefulness of maximum standardized uptake values (SUVmax) in differentiating benign and malignant lesions. Methods: We performed an electronic medical record search looking at all 18F-FDG-PET or PET/CT reports during the study period of 12/01/2015 to 05/31/2019 that included the keyword ‘thyroid’ in the impression. Exclusion criteria included a history of thyroid disease or malignancy, known lesion(s) detected on previous clinical or radiological examinations and diffuse radiotracer uptake. Of the 476 reports reviewed, 136 cases were included in the study. Results: Common indications included initial staging or restaging of lymphoma (diffuse large B-cell, mantle-cell, T-cell types) (27.9%), lung adenocarcinoma (18.4%), head and neck cancer (16.9%) and breast cancer (11%). Fifty-eight (42.6%) patients had metabolically inactive lesions; five (8.6%) underwent further investigation with thyroid US and 3 subsequently with FNA (5%). All 3 had benign cytology. Seventy-seven (56.6%) patients had metabolically active lesions and 25 (32.5%) underwent imaging with thyroid US. Twelve (15.6%) had FNA; eight (66.7%) had benign cytology, two (16.7%) revealed atypia of undetermined significance and two (16.7%) were malignant. Biopsy for the two patients with malignant cytology showed follicular cell neoplasm of oncocytic hurtle cell type, and invasive follicular carcinoma with focal insular and papillary features and extensive capsular and vascular invasion. The mean SUVmax in malignant vs benign lesions was 9.05 and 6.41 respectively. Conclusion: The malignancy rate was 2.6% amongst all patients with 18F-FDG-avid TI and 8% amongst patients with metabolically active lesions who were investigated with thyroid US+/- FNA. This is significantly lower than malignancy rates previously reported in the literature. The evident inhomogeneity in the literature is likely multifactorial and may be explained in part by a dissimilarity among studies, and an informed decision by some to avoid invasive testing in the context of poor prognosis from underlying non-thyroidal cancer. Research is needed to determine the cohort of patients who could potentially benefit from further evaluation and treatment.

Analysis of intra-observer and inter-observer variability of pathologists for non-benign thyroid fine needle aspiration cytology according to Bethesda system categories.

To examine the intra- and inter-observer variability for non-benign thyroid cytological subcategories according to the Bethesda classification system after the second review. Between November 2018 and May 2019, thyroid fine needle aspiration biopsies of 381 nodules were retrospectively evaluated. Among them, 74 non-benign (category III-VI) thyroid biopsies, analyzed according to the Bethesda system (pathologist 1:40 vs pathologist 2:34) by two independent pathologists, were reassessed by the same pathologists and by a cytopathologist. In this observer-blinded study, weighted Cohen's kappa was used to assess the intra-observer agreement, and Krippendorff's alpha was used to assess the inter-observer agreement. At the first and second evaluations of pathologists 1 and 2, the percentage agreement was 62.5% for pathologist 1 and 58.8% for pathologist 2. The intra-observer agreement was substantial (κ=0.705) for pathologist 1, and moderate (κ=0.447) for pathologist 2. In the second evaluation of pathologist 1 and 2, which was compared with the cytopathologist, the agreement percentage of pathologist 1 with the cytopathologist was 50.0%, and that of pathologist 2 was 56.8%. The inter-observer agreement was below the lowest acceptable limit for an overall agreement (α=0.634) among the three raters. The inter-observer agreement was only acceptable between the cytopathologist and the second pathologist, while it was low between the other raters. In the evaluation of the non-benign nodules, the mean category score of the cytopathologist was 3.22 and lower than both pathologists (3.73 and 3.58, respectively). The intra-observer agreement of pathologists was moderate-to-substantial in the evaluation of non-benign thyroid biopsies according to the Bethesda reporting system. However, the inter-observer agreement was below the lowest acceptable limit when the cytopathologist was taken as a reference.