Diagnosis of follicular lesions of undetermined significance in fine-needle aspirations of thyroid nodules

Cytomorphological categorization of thyroid lesions according to the bethesda system for reporting thyroid cytology and correlation with their histological outcome: An indian oncology centre experience

Objective:

Material and Methods:

Results:

Conclusion:

Galectin-3 and CD117 immunocytochemistry in the diagnosis of indeterminate thyroid lesions: A pilot study

BACKGROUND

Indeterminate thyroid lesions have always been a grey zone in the field of thyroid cytopathology. Immunocytochemistry (ICC) has emerged as a promising tool to correctly classify these indeterminate thyroid lesions into benign and malignant. Hence we planned to assess a panel of immune markers in the diagnosis of indeterminate thyroid lesions consisting of Galectin-3, considered positive for malignancy and CD117 which is positive in benign follicular epithelial cells and negative in malignant lesions.

METHODS

All the thyroid aspirates reported as indeterminate lesions over a period of 3 years were evaluated. Galectin-3 and CD117 immunocytochemistry was done in 50 alcohol fixed Pap stained smears of AUS/FLUS, FN/SFN and SM category lesions. The expression of both immune markers was assessed by semi-quantitative method and ICC score was calculated.

RESULT

Of 50 indeterminate lesions, 29 were positive for Galectin-3 and 21 were negative. CD117 was positive in 19 cases and rests 31 were negative. With the use of this ICC panel 29/30 indeterminate lesions in which histopathological correlation was available could be recategorized correctly into benign and malignant. The combined sensitivity and specificity of Galectin-3 and CD117 for categorising the indeterminate lesions into malignant category was 100%.

CONCLUSION

The combined use of positive and negative immune markers for thyroid malignancy increases the sensitivity and specificity of ICC to categorise the indeterminate thyroid lesions into benign and malignant. In cases with discordant ICC results we propose that inclusion of one additional positive and/or negative marker may resolve the diagnostic dilemma.

The Role of Cell Blocks and Immunohistochemistry in Thyroid Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance Bethesda Category

INTRODUCTION

Thyroid cytology is a widely accepted tool in the clinical triaging of nodular lesions. Cell blocks (CBs) can help in the diagnosis of atypical lesions, namely, thyroid Bethesda category of Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS).

METHODS

In a series of 224 AUS/FLUS thyroid samples with CB, we studied CB cellularity and feasibility of 3 immunohistochemical markers (cytokeratin 19 [CK19], HBME-1, and galectin-3) apart and in combination.

RESULTS

The CBs were non-diagnostic in 34 cases. Twenty-four CBs contained <10 cells, 45 CBs 10-50 cells, and 121 CBs >50 cells. Notably, more cellularity was found in CBs performed by plasma-thrombin and in-house techniques (p < 0.001). The diagnostic accuracy to detect malignancy was 65.1% for CK19, 72.1% for HBME-1, and 70.3% for galectin-3.

CONCLUSION

In conclusion, CB cellularity is essential for successful immunohistochemistry application and further diagnostic workup of AUS/FLUS cases.

Atypia of undetermined significance/follicular lesion of undetermined significance: Asian vs. non-Asian practice, and the Singapore experience

The Bethesda System for Reporting Thyroid Cytopathology has paved the way for comparisons of the practice of thyroid cytology in many different regions. However, there have been comparatively few studies documenting differences between Asian and non-Asian practice. Here, we aim to compare a few key parameters between the two regions, focusing on the indeterminate category of atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS). We compared its incidence, resection rates (RRs), risk of malignancy (ROM), rate of repeat fine needle aspiration (rFNA), ROMs of cytomorphologic subcategories of nuclear atypia (AUS-N) vs. architectural atypia (AUS-A), and, finally, the incidence of papillary thyroid carcinoma (PTC) vs. follicular neoplasms (FNs) in resected AUS/FLUS cases in Asian and non-Asian regions. Where possible, these metrics were compared with the Singapore experience from a tertiary referral institution. While the incidence of AUS/FLUS was similar in both regions, we found geographical differences in the RRs and ROMs, which may reflect a higher collective threshold for surgery in Asian countries. However, both cohorts showed higher ROMs in the AUS-N subcategory as compared to the AUS-A subcategory, supporting the subclassification of the AUS/FLUS based on the presence of nuclear atypia. We also observed a higher incidence of AUS-N coupled with a higher incidence of PTC in resected AUS/FLUS nodules in Asian cohorts, while AUS-A and follicular-patterned neoplasms featured more prominently in the non-Asian cohorts. These incidences may account for the starkly different molecular approaches that we noted-in Asian (chiefly Korean and Chinese) centers, BRAF mutational analysis was favored, while gene panels and gene expression classifiers were more frequently applied in non-Asian centers (chiefly in the United States of America). Overall, the data from Singapore appears more closely aligned to non-Asian trends, despite its geographical location in Southeast Asia and its predominantly Asian population. We conclude that there is significant heterogeneity in the outcomes of the AUS/FLUS categories between and within regions, which is only partially explained by regional variations, and may also reflect different regional diagnostic and management practices. This highlights the importance of understanding the local context in the interpretation of indeterminate Bethesda categories, rather than adopting a "one-size fits all" approach.

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC): A report of 2,781 cases in a Chinese population

Objective

To evaluate the diagnostic utility of The Bethesda System for Reporting Thyroid Cytology (TBSRTC) at Peking University Cancer Hospital, the incidence of noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and the impact of reclassification on cytopathological outcomes.

Methods

We performed a retrospective study of thyroid fine-needle aspiration (FNA) cases between April 2014 and March 2019. The FNA results were classified according to TBSRTC. Post-surgery histological findings were followed up.

Results

A total of 2,781 thyroid FNAs were performed. The incidences of the 6 diagnostic categories (DCs I-VI) were 14.8%, 17.1%, 15.8%, 2.3%, 11.6% and 38.5%, respectively. A total of 1,122 patients (40.3%) had corresponding histological results. NIFTP accounted for 0.4% of papillary thyroid carcinoma (PTC) cases, and there was no significant difference in the risk of malignancy (ROM) for each TBSRTC DC between "NIFTP=carcinoma (Ca)" and "NIFTP≠Ca". When "NIFTP=Ca", the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TBSRTC were 98.0%, 84.0%, 99.4%, 58.3%, and 97.5%, respectively. When "NIFTP≠Ca", the sensitivity, specificity, PPV, NPV and accuracy of the TBSRTC were 98.1%, 81.5%, 99.3%, 61.1%, and 97.5%, respectively.

Conclusions

TBSRTC is effective in the preoperative diagnosis of thyroid nodules in Peking University Cancer Hospital. The impact of the reclassification of NIFTP on cytopathological outcomes is limited because of its low incidence, and the revised ROMs are not suitable for Asian patients.

Thyroid Bethesda Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance (AUS/FLUS): A Heterogenous Group

Background:

The Bethesda system of reporting thyroid cytopathology (BSRTC) was introduced in 2007. The third category of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) poses difficulties for the pathologist, and different papers have been published varying the risks of malignancy.

Aims:

(1) Evaluation of the cytological features of thyroid lesions according to BSRTC. (2) After resection, correlation with histopathological report to evaluate the risk of malignancy (ROM) and the risk of neoplasm (RON). (3) Division of category III into six subgroups based on cytological findings and assessment of ROM and RON.

Materials and Methods:

A total of 282 patients with diagnosed thyroid lesions underwent fine-needle sampling under ultrasound guidance. Smears were prepared and stained with May–Grunwald–Giemsa stain and Papanicolaou stain.

Results:

Of 282 cases, there were 9 cases (3.1%) of category I, 157 cases (55.8%) of category II, 24 cases (8.5%) of category III, 20 cases (7.1%) of category IV, 14 cases (4.8%) of category V, and 58 cases (20.7%) of category VI. The RON was 60, 17.1, 63.1, 77.7, 91.7, and 98.2% and the ROM was 60, 14.3, 26.3, 38.9, 91.7, and 96.3% in categories I, II, III, IV, V, and VI, respectively. The RON was 0, 75, 50, 100, 66.6, and 100% and the ROM was 0, 25, 50, 100, 16.6, and 0% in subgroups 1, 2, 3, 4, 5, and 6, respectively. We have proposed a system of subgrouping AUS/FLUS that may help to dispel the confusion generated by an AUS/FLUS report, and provide with a more exact and reproducible diagnostic and prognostic tool.

When Is Thyroidectomy the Right Choice? Comparison between Fine-Needle Aspiration and Final Histology in a Single Institution Experience

OBJECTIVES

The aim of this study was to compare SIAPEC-IAP-based cytological reports with their corresponding histological diagnoses to establish when thyroidectomy is the right choice in the management of thyroid diseases.

STUDY DESIGN

This is a retrospective review of all the consecutive thyroidectomies/lobectomies performed at Maria Vittoria Hospital during the 10-year period between January 2005 and December 2015. Patients who underwent both fine-needle aspiration (FNA) and surgical procedures in our institution were included in the study.

RESULTS

A total of 260 patients underwent both FNA and a thyroid surgical procedure at Maria Vittoria Hospital; 111 (42.69%) had a malignant histological report. The final cytological diagnosis was nondiagnostic (TIR-1) in 19 cases (7.31%), benign (TIR-2) in 83 cases (31.92%), indeterminate (TIR-3) in 96 cases (36.92%), suspicious for malignancy (TIR-4) in 22 cases (8.46%), and diagnostic for malignancy (TIR-5) in 40 cases (15.38%). Among the 96 cases with TIR-3 cytology, after the review, 44 (16.92%) were classified as TIR-3A and 52 (20%) as TIR-3B. The prevalence of malignancy among TIR-3A cases was 20.45% (9/44) and among TIR-3B cases 53.85% (28/52). The difference was statistically significant (p = 0.0007).

CONCLUSIONS

Our data suggest that follow-up alone is not sufficient in TIR-3A patients given the high prevalence of malignancy within that diagnostic category (20.45%) and the low sensitivity (75.68%) and specificity (59.32%) in the distinction between TIR-3A and TIR-3B. Regarding patients with a multinodular goiter and TIR-2 at FNA, the surgical approach should not be excluded.

Evaluation of thyroid nodules classified as Bethesda category III on FNAC

Background:

The Bethesda (BSRTC) category III has been ascribed a malignancy rate of 5–15%, however, the probability of malignancy remains variable.

Aim:

To evaluate category III with respect to its rate and risk of malignancy and substratify it.

Settings and Design:

Atypia of undetermined significance/Follicular lesion of undetermined significance (AUS/FLUS) percentage, cytohistological correlation, and risk of malignancy were analyzed and substratification was done.

Material and Methods:

Category III cases over a 2-year period were analyzed retrospectively.

Statistical Analysis:

Two-tailed Fisher exact test, with a level of significance set at 0.05, was performed for data analysis.

Results:

Of 1169 thyroid fine needle aspirations (FNAs), 76 (6.5%) were category III. A total of 48 patients had follow up; 24 patients underwent surgery, 12 repeat FNA, and 12 were clinically followed. Repeat FNA cytology was unsatisfactory in 8.3%, benign in 66.7%, AUS in 8.3%, and follicular neoplasm in 16.7%. Of the 24 operated, 8 (33.3%) were malignant (follicular variants of papillary thyroid carcinoma), 5 (20.8%) were follicular adenomas, and 11 (45.8%) were non-neoplastic. Among all AUS/FLUS nodules with follow-up, malignancy was confirmed in 16.7% (8/48) whereas with nodules triaged to surgery only, the malignancy rate was 33.3% (8/24). Substratification into categories of “cannot exclude PTC” and “favor benign” helped detect malignancy better, as 85.7% cases in the first subcategory (P < 0.001) and none (P < 0.02) in the last proved malignant.

Conclusion:

Though the rate of Category III in our study is in accordance to BSRTC, the risk of malignancy in AUS/FLUS nodules is higher. Substratification of AUS/FLUS may help better patient management.

Application of the Bethesda Classification for Thyroid Fine-Needle Aspiration: Institutional Experience and Meta-analysis

Context.—Fine-needle aspiration (FNA) biopsies have been an important component in the preoperative evaluation of thyroid nodules. Until the introduction of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) in 2008, individual institutions had developed their own diagnostic categories. The BSRTC proposed 6 categories in an attempt to standardize reporting of thyroid FNA.

Objective.—To present a 15-year experience of thyroid FNA at one institution, including data before and after introduction of the BSRTC. The risk of malignancy is compared with the meta-analysis of high-quality published data.

Data Sources.—Data sources were PubMed, a manual search of references, and institutional data.

Conclusions.—The diagnostic categories developed at our institution were similar to those proposed by the BSRTC, with best fit into the 6 categories easily accomplished and reported in the final 2 years of the study. Significant differences were noted in the frequencies of cases in diagnostic categories Benign (II; P = .003), Suspicious for follicular neoplasm/Follicular neoplasm (IV; P &lt; .001), and Malignant (VI; P = .003) after the introduction of the BSRTC. Eighteen published articles met the criteria for inclusion in the meta-analysis. The risk of malignancy in each category in our institution was similar to that determined in the meta-analysis, except for Insufficient for diagnosis (I; 20% versus 9%–14%). Meta-analysis showed an overlapping 95% CI of risk of malignancy between Atypia of undetermined significance/Follicular lesion of undetermined significance (III; 11%–23%) and Suspicious for follicular neoplasm/Follicular neoplasm (IV; 20%–29%), suggesting similar risks of malignancy. The use of newer molecular tests for these indeterminate cases may further refine risk assessment.

A Pilot Study of Galectin-3, HBME-1, and p27 Triple Immunostaining Pattern for Diagnosis of Indeterminate Thyroid Nodules in Cytology With Correlation to Histology

Supplemental Digital Content is available in the text.

Indeterminate thyroid nodules form a heterogenous group of lesions that constitute 5% to 30% of thyroid cytology diagnoses. We introduce a triple immunostaining protocol for subtyping. Galectin-3, HBME-1, and p27 triple immunostaining, performed on destained cytology slides and formalin-fixed paraffin-embedded tissue, was developed and applied to 51 patients retrospectively with preoperative cytologic diagnoses of follicular lesion of undetermined significance (n=40), atypia of undetermined significance (n=6), and suspicious for follicular neoplasm (n=5). The malignant rate in this series was 43.1% (22/51). A hierarchal evaluation algorithm was generated based on digital image quantitation of triple-stained histologic sections, and applied to both cytology and histology specimens. Fifty of 51 cytology cases have triple staining validated by internal controls. In cytology specimens, the individual sensitivities and specificities of p27, Galectin3, and HBME1 for cancer with 95% confidence interval are: 86.2% (0.674, 0.955)/66.7% (0.431, 0.845); 77.3% (0.542, 0.913)/72.4% (0.525, 0.866); and 72.7% (0.496, 0.884)/93.1% (0.758, 0.988), respectively. Sensitivity is increased to 95.5% (0.751, 0.998), but specificity is decreased to 69.0% (0.490, 0.840), if Galectin3 and HBME1 are both used in combination as markers for malignancy. However, the level of specificity is increased to 86.2% (0.674, 0.955) and sensitivity remains high 100% (0.808, 1) if in addition, using the Galectin3/HBME1:p27 ratio (ratio ≥2 indicating malignancy) for 2 or 3 markers positive cases. Thus, the triple staining method on cytology slides and histology sections shows a similar sensitivity/specificity/positive predictive value/negative predictive value of 100.0%/86.2%/84.0%/100.0% and 95.5%/86.2%/84.0%/96.2%, respectively (P=0.92). Overall, p27 is the most frequent single positive marker (19/50, 38% in cytology), consistent with benign nature of most indeterminate thyroid nodules. Galectin-3 and HBME-1 colocalization (positive in the same cell) was demonstrated in thyroid cancer in 45.5% (10/22) of histology sections, but in none of the normal thyroid tissues and benign thyroid lesions. This supports the notion that synchronous activation of Galectin-3 and HBME-1 occurs in thyroid malignancy and is highly specific for malignancy. We have demonstrated the performance and pattern of triple immunostaining for subtyping indeterminate thyroid nodules. Further studies and validation in different larger populations are warranted.

Outcome of Subclassification of Indeterminate (Thy-3) Thyroid Cytology into Thy-3a and Thy-3f

OBJECTIVES

The British Thy system is a widely used classification system for reporting thyroid fine-needle aspiration (FNA) cytology. The Royal College of Pathologists in 2009 recommended the subdivision of the Thy-3 (indeterminate) category into Thy-3a (atypia) and Thy-3f (follicular neoplasm). Our objective was to examine the malignancy rates of Thy-3a and Thy-3f cases at our institution and to investigate whether the risk of malignancy in Thy-3a cases is reduced by FNA on a different occasion showing benign cytology.

METHODS

This is a retrospective study of 748 thyroid nodules undergoing 1,032 FNAs, with indeterminate (Thy-3) cytology subdivided into Thy-3a and Thy-3f. Cases were correlated with final histology in surgical cases. Incidental carcinomas occurring outside the biopsied nodule were discounted.

RESULTS

A total of 109 nodules had a final cytological diagnosis of Thy-3a, of which 67 underwent surgery, with an incidence of malignancy of 13.4% (9/67); 90 nodules had a final cytological diagnosis of Thy-3f, of which 84 underwent surgery, with an incidence of malignancy of 17.9% (15/84). The difference in malignancy rates was not significant (p = 0.51). The incidence of malignancy in nodules with benign and Thy-3a cytology on separate occasions was not significantly different from cases with a single Thy-3a cytology.

CONCLUSIONS

Thyroid nodules with Thy-3a cytology have a slightly lower risk of malignancy than Thy-3f cases. However, the difference is not significant and does not appear to be reduced by FNA on a separate occasion showing benign cytology. Management decisions for patients with Thy-3a cytology should be taken carefully to avoid missing cancers.

Fine needle aspiration biopsy of thyroid nodules: cytologic and histopathologic correlation of 1096 patients

Via routinely used thyroid function tests, scintigraphy and ultrasonography (USG), important information is obtained in the clinical and diagnostic practice for thyroid nodules. However, the distinction between benign and malignant lesions cannot precisely be performed with these tests. Thyroid fine needle aspiration biopsy (FNAB) is considered the most reliable diagnostic method in the differentiation between benign and malignant thyroid nodules. It has recently been likely to perform aspiration from deeper nodules via the implemention of FNAB along with USG. Today, in cytopathological examination of thyroid FNAB, standardized Bethesda System for Reporting Thyroid Cytopathology (BSRTC) system is used. Here, FNAB was performed in 1096 patients with thyroid nodules in the Medical School of Selcuk University between January 2009 and July 2014. Patients consisted of 919 women and 177 men between 12 and 87 years of age. Evaluated via BSRTC, the results were classified as unsatisfactory, benign, atypia (or follicular lesions) of undetermined significance (AUS), follicular neoplasm or lesions suspicious for follicular neoplasm (FN), suspected malignant and malignant. After FNAB, 183 patients were operated and evaluated histopathologically. Histological malignancy rates of the categories were as follows: 16% (5), 15% (6) 14% (1) 60% (9), 72% (18) and 97% (63), respectively. In our study, we aimed to compare FNAB results of thyroid nodules with histopathology results after thyroidectomy and to show the sensitivity and specificity of FNAB technique to be higher in the follow-up and diagnosis of thyroid lesions. Given the malignancy detection rate in the follow-up of patients whose cytology was reported as inadequate, we also consider follow-ups are important in these patients.

Evaluation and management of thyroid nodules with atypia/follicular lesion of undetermined significance on fine-needle aspiration

Since the introduction of the Bethesda System for Reporting Thyroid Cytopathology in 2008, the management of thyroid nodules has become more standardized, with clearly defined algorithms based on risk of malignancy for each of the six cytologic categories. However, the management of a thyroid nodule with a fine-needle aspiration biopsy classified as Bethesda III, or atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), remains controversial due to the cytologic heterogeneity and the variability in the reported rates of malignancy. In this review, the history and rationale for the new Bethesda III category is examined, the reported incidence and risk of malignancy from published studies is reviewed and recommendations for management of patients with a thyroid nodule and AUS/FLUS are provided. Recent advances in molecular analysis and their role in the evaluation of patients with AUS/FLUS are also discussed.

Evaluation of indeterminate thyroid cytology by second-opinion diagnosis or repeat fine-needle aspiration: which is the best approach?

OBJECTIVE

This study investigated a published series evaluating the role of second-opinion diagnosis (SOD) or repeat fine-needle aspiration cytology (RFNA) for indeterminate thyroid aspirates.

STUDY DESIGN

Twenty-three studies were selected and the following parameters were analyzed: disagreement between SOD or RFNA and the original diagnosis (OD), reclassification of OD according to the Bethesda system for reporting thyroid cytopathology, the rate of definitive diagnosis and the diagnostic performance of SOD and RFNA.

RESULTS

7,154 thyroid FNAs were retrieved from 9 studies that investigated the role of SOD, including 1,048 (14.6%) cases originally reported as indeterminate. The 14 studies that analyzed the role of thyroid RFNA comprised 67,581 FNAs and included 7,246 (10.7%) indeterminate cases. A definitive diagnosis was achieved by SOD in 450 cases (42.9%) and RFNA in 1,645 cases (57.2%, p=0.0001). Based on cases with histological follow-up, SOD demonstrated significantly higher rates of positive predictive value and accuracy than RFNA (55.8 vs. 37.7%, p=0.0001; 67.4 vs. 56.0%, p=0.0034, respectively).

CONCLUSIONS

Both SOD and RFNA demonstrated an improvement in the diagnosis of initially indeterminate thyroid FNAs. RFNA achieved a definitive diagnosis for the majority of indeterminate cases. Regarding histological follow-up, SOD was shown to be more accurate than RFNA.

Thyroid atypia of undetermined significance or follicular lesion of undetermined significance: an indispensable Bethesda 2010 diagnostic category or waste garbage?

OBJECTIVE

The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) was introduced in thyroid cytology in 2007 and is now generally accepted. BSRTC categories include a morphologic description and risk of malignancy as well as follow-up suggestions in each group. However, the category entitled 'atypia of undetermined significance or follicular lesion of undetermined significance' (AUS/FLUS) is problematic. This category is heterogeneous and has been overused so far.

STUDY DESIGN

Twenty-six studies were included in a meta-analysis. In addition to AUS/FLUS percentage, we analysed repeated AUS/FLUS percentage, cytological and histological correlations, and risk of malignancy and neoplasm for AUS/FLUS. Furthermore, stratification, inter- and intra-observer variability, and the possibility of a switch to another category and its clinical consequences were reviewed.

RESULTS

Out of a total of 81,833 cases, AUS/FLUS accounted for 10.9%, with a 34% risk of malignancy. Persistent AUS/FLUS was found in 21.6% in repeated cytology. Cytohistological correlation was analysed from 16 studies (4,964 cases), revealing 10.4% as AUS/FLUS and a 21.5% risk of malignancy.

CONCLUSIONS

An AUS/FLUS category seems to be currently reasonable with clearly defined cytomorphological criteria which do not correspond unequivocally with those of the other categories. An AUS/FLUS category is justified and possible means of its improvement with immunohistochemistry, molecular analysis and imaging are discussed.

Follicular nodules (Thy3) of the thyroid: is total thyroidectomy the best option?

Background

Identification of the best management strategy for nodules with Thy3 cytology presents particular problems for clinicians. This study investigates the ability of clinical, cytological and sonographic data to predict malignancy in indeterminate nodules with the scope of determining the need for total thyroidectomy in these patients.

Methods

The study population consisted of 249 cases presenting indeterminate nodules (Thy3): 198 females (79.5%) and 51 males (20.5%) with a mean age of 52.43 ± 13.68 years. All patients underwent total thyroidectomy.

Results

Malignancy was diagnosed in 87/249 patients (34.9%); thyroiditis co-existed in 119/249 cases (47.79%) and was associated with cancer in 40 cases (40/87; 45.98%). Of the sonographic characteristics, only echogenicity and the presence of irregular margins were identified as being statistically significant predictors of malignancy. 52/162 benign lesions (32.1%) and 54/87 malignant were hypoechoic (62.07%); irregular margins were present in 13/162 benign lesions (8.02%), and in 60/87 malignant lesions (68.97%). None of the clinical or cytological features, on the other hand, including age, gender, nodule size, the presence of microcalcifications or type 3 vascularization, were significantly associated with malignancy.

Conclusions

The rate of malignancy in cytologically indeterminate lesions was high in the present study sample compared to other reported rates, and in a significant number of cases Hashimoto’s thyroiditis was also detected. Thus, considering the fact that clinical and cytological features were found to be inaccurate predictors of malignancy, it is our opinion that surgery should always be recommended. Moreover, total thyroidectomy is advisable, being the most suitable procedure in cases of multiple lesions, hyperplastic nodular goiter, or thyroiditis; the high incidence of malignancy and the unreliability of intraoperative frozen section examination also support this preference for total over hemi-thyroidectomy.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.