Adem Karataş1, Serdar Giray2, Önder Peker3, Özlem Aydın3, Umut İnce3, Faruk Alagöl4, Mete Düren1, Halil D. Azizlerli4

1İ.Ü. Cerrahpaşa Tıp Fakültesi, Genel Cerrahi Anabilim Dalı, İstanbul, Türkiye
2Florence Nightingale Hospital, Genel Cerrahi, İstanbul, Türkiye
3Nişantaşı Patoloji Grubu, İstanbul, Türkiye
4İ.Ü. İstanbul Tıp Fakültesi Endokrinoloji Bilim Dalı, İstanbul, Türkiye

Abstract

Introduction: Fine needle aspiration biopsy (FNAB) is the most important method for development of a suitable treatment protocol for thyroid nodules. However, FNAB may not always give the sufficient or correct result for the characteristics of a nodule. We used the diagnostic classification Bethesta recommended by Papanicolau Society of Cytopathology to analyze the coherence of cytology and histology.

Material and Methods: The results of histologic analysis (HA) of 245 patients which had undergone FNAB were analyzed. FNAB results are classified as nondiagnostic, benign, follicular lesion, follicular neoplasm, suspect malignant and malignant according to Bethesta 2007.

Results: There were 193 female and 52 male patients. The average age was 42.8 years (17-81 years). The inadequate FNAB of 13 patients were repeated. The results were benign in 9 patients and follicular lesion in 4 patients. These results were included in suitable Bethesta group. Among the 86 patients who had benign results after FNAB, 69 patients (28%) had benign results and 17 patients (7%) had follicular adenoma in the histological analysis.100 patients had follicular lesions or follicular neoplasm. These patients were evaluated in 3 subgroups according to their histological types. First group: 11 patients were diagnosed as follicular neoplasm and Hurthle cell neoplasm with FNAB and 5 (2%) of them had follicular adenoma in histological analysis and 2 patients (1%) had Hurthle cell adenoma (HCA) and four of the patients (2%) had PTC. Second group: 64 patients were diagnosed as follicular lesions by FNAB. 59 patients (24%) had follicular adenoma, 3 patients (1%) had HCA, 2 patients (1%) had benign results in the histological analysis. Third group: 25 patients were diagnosed as follicular lesions by FNAB. 3 patients (1%) had follicular thyroid cancer (FTC) , 2 patients (1%) had PTC,10 patients (4%) had follicular adenoma+ PTC in another focus, 8 patients (3%) had benign results and 2 patients (1%) had benign results+PTC in another focus in the histological analysis. Seven patients who had a suspect malignant FNAB result, PTC were accepted as PTC with histological analysis (2%). All of the 52 patients (21%) with malignant findings at FNAB, were diagnosed as PTC with histological analysis.

Discussion: FNAB is a very important resource for setting the treatment of thyroid nodules. The success of cytologic results of fine needle aspiration biopsy can be improved by knowledge, experience, technical equipment and by setting a standard terminology for pathology. The Bethesta Classification which is consisted of six diagnostic categories is a useful evaluation method for cytologic analysis. Among 6 of the groups the group with the most cytological diversity was the group with follicular lesion and neoplasm. In this group the rate of malignancy is 9%.

Keywords: Bethesta classification, FNAB, follicular lesion, thyroid