The Evaluation of Malignancy Rates of Nondiagnostic Cases in Thyroid Fine-Needle Aspirations

Abstract

Aim: In this study, it was aimed to investigate the malignancy rates of nondiagnostic (ND) thyroid fine-needle aspiration cytology (FNAC) material by evaluating either the result of the second FNAC or resection/biopsy materials.

Method: Among the 1165 thyroid FNAC cases evaluated in the Pathology Department of Başakşehir Çam and Sakura City Hospital within 9 months (October 2020-June 2021), 102 cases (8,7%) diagnosed with ND were included in the study. At the end of the 6-15 months follow-up period after the diagnosis of ND, the results of the second FNAC or resection (thyroidectomy, lobectomy)/biopsy of the cases were evaluated. Diameter and sonographic features of thyroid nodules (solid, cystic, mixed) were also noted.

Results: 49% of the cases (n:50) had a second FNAC. Resection/biopsy was performed in only 12 (11,8%) cases. Of these 62 cases, 39 were diagnosed by second FNAC and 7 by resection/biopsy as benign (74,1%), and 5 cases were diagnosed as malignant by resection/biopsy. 7 cases were diagnosed as nondiagnostic again after the second FNAC. Final diagnosis (by resection) of the case whose second FNAC result was reported as suspicious for malignancy was papillary microcarcinoma. This case was included in the group ‘diagnosed as malignant only by resection/biopsy. In other words, malignancy was detected in 5 of 62 patients who underwent a second FNAC or resection/biopsy. The risk of malignancy was found to be 8% in the patient population included in the study with the diagnosis of ND.

Conclusion: A low rate of NE results were found in this ultrasound-guided thyroid series (8,7%). After the second FNAC or resection, malignancy rates was found to be 8%. Although this result is compatible with the results of some studies, it is considerably lower than others. It would be appropriate to follow up on ND nodules with their clinical/sonographic features. Additional studies with large series will be more helpful in determining the malignancy rates of the ND group.

Keywords

• Thyroid cancer
• papillary
• biopsy
• fine-needle
• cytology
• Tiroid kanser
• papiller
• biyopsi
• ince-iğne
• sitoloji

Tiroid İnce İğne Aspirasyonlarında Tanısal Olmayan Olguların Malignite Oranlarının Değerlendirilmesi

Abstract

Amaç: Çalışmada nondiagnostik (ND) tiroid ince iğne aspirasyon sitolojisi (İİAS) materyalinin malignite oranlarının araştırılması (ikinci İİAS sonucu veya rezeksiyon/biyopsi materyalleri değerlendirilerek) amaçlandı.

Yöntem: Başakşehir Çam ve Sakura Şehir Hastanesi Patoloji Bölümü'nde 9 ay (Ekim 2020-Haziran 2021) içinde değerlendirilen 1165 tiroid İİAS olgusundan ND tanısı alan 102 olgu (%8,7) çalışmaya dahil edildi. ND tanısı konulduktan sonra 6-15 aylık takip süresi sonunda olguların ikinci İİAS veya rezeksiyon (tiroidektomi, lobektomi)/biyopsi sonuçları değerlendirildi. Tiroid nodüllerinin (solid, kistik, mikst) çap ve sonografik özellikleri de kaydedildi.

Bulgular: Vakaların %49'unda (n:50) ikinci bir İİAS yapıldı. Sadece 12 (%11.8) olguda rezeksiyon/biyopsi yapıldı. İkinci İİAS ile AUS tanısı alan üç olguda rezeksiyon/biyopsi yapılmadı. Bu 62 olgunun 39'una ikinci İİAS, 7'sine rezeksiyon/biyopsi ile benign (%74,1), 5 olguya ise rezeksiyon/biyopsi ile malign tanısı konuldu. 7 olgu ikinci FNAC sonrası yeniden nondiagnostik tanısı aldı. İkinci İİAS sonucu malignite şüpheli olarak bildirilen olgunun kesin tanısı (rezeksiyon ile) papiller mikrokarsinom olarak belirlendi. Bu olgu ‘sadece rezeksiyon/biyopsi ile malign olarak teşhis edilen' gruba alındı. Yani ikinci İİAS veya rezeksiyon/biyopsi yapılan 62 hastanın 5'inde malignite saptandı. ND tanısı ile çalışmaya alınan hasta popülasyonunda malignite riski %8 olarak bulundu.

Sonuç: Ultrason rehberliğinde tiroid İİAS serimizde düşük oranda ND sonuçları bulunmuştur (%8,7). İkinci İİAS veya rezeksiyon sonrası malignite oranları %8 olarak bulundu. Bu sonuç bazı çalışmaların sonuçları ile uyumlu olsa da diğerlerine göre oldukça düşüktür. ND nodüllerin klinik/sonografik özellikleri ile takip edilmesi uygun olacaktır. Geniş serili ek çalışmalar, ND grubunun malignite oranlarının belirlenmesinde daha fazla yardımcı olacaktır.

Keywords

• Tiroid kanser
• papiller
• biyopsi
• ince-iğne
• sitoloji

References

1. Rossi ED, Morassi F, Santeusanio G, Zannoni GF, Fadda G. Thyroid fine needle aspiration cytology processed by ThinPrep: An additional slide decreased the number of inadequate results. Cytopathology. 2010;21(2):97-102.
2. Ali SZ, Cibas ES, ed(s). The Bethesda System for Reporting Thyroid Cytopathology. 2nd ed. Switzerland: Springer; 2018.
3. Cibas ES, Ali SZ. The bethesda system for reporting thyroid cytopathology. Thyroid. 2009;19:1159–1165.
4. Cibas ES, Ali SZ. The 2017 bethesda system for reporting thyroid cytopathology. Thyroid. 2017;27:1341-1346.
5. Güney G, Şahiner İT. Malignancy rates of thyroid cytology: Cyst fluid benign or non-diagnostic? Med Sci Monit. 2017;21(23):3556-3561. doi:10.12659/msm.905718.
6. Baloch Z, LiVolsi VA, Jain P, et al. Role of repeat fine-needle aspiration biopsy (FNAB) in the management of thyroid nodules. Diagn Cytopathol. 2003;29:203–206.
7. MacDonald L, Yazdi HM. Nondiagnostic fine needle aspiration biopsy of the thyroid gland: A diagnostic dilemma. Acta Cytol. 1996;40:423–428.
8. Ferreira MA, Gerhard R, Schmitt F. Analysis of nondiagnostic results in a large series of thyroid fine-needle aspiration cytology performed over 9 years in a single center. Acta Cytol. 2014;58(3):229-234.

9. Gunes P, Canberk S, Onenerk M, et al. A different perspective on evaluating the malignancy rate of the non-diagnostic category of the bethesda system for reporting thyroid cytopathology: A single institute experience and review of the literature. PLoS One. 2016;11(9):e0162745.
10. Bongiovanni M, Spitale A, Faquin WC, Mazzucchelli L, Baloch ZW. The bethesda system for reporting thyroid cytopathology: A meta-analysis. Acta Cytol. 2012;56(4):333–339.
11. Coorough N, Hudak K, Jaume JC, et al. Non-diagnostic fineneedle aspirations of the thyroid: Is the risk of malignancy higher? J Surg Res. 2013;184:746–750.
12. Haugen BR, Alexander EK, Bible KC, et al. 2015 american thyroid association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: The american thyroid association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid. 2016;26(1):1-133.
13. Naïm C, Karam R, Eddé D. Ultrasound-guided fine-needle aspiration biopsy of the thyroid: Methods to decrease the rate of unsatisfactory biopsies in the absence of an on-site pathologist. Can Assoc Radiol J. 2013;64(3):220–225.
14. Jo VY, Stelow EB, Dustin SM, Hanley KZ. Malignancy risk for fine-needle aspiration of thy- roid lesions according to the bethesda system for reporting thyroid cytopathology. Am J Clin Pathol. 2010;134(3):450–456.
15. García-Pascual L, Barahona MJ, Balsells M, et al. Complex thyroid nodules with nondiagnostic fine needle aspiration cytology: Histopathologic outcomes and comparison of the cytologic variants (cystic vs. acellular). Endocrine. 2011;39(1):33–40.