Oxyphilic and follicular thyroid tumors - the correlation between the cytopathologic diagnosis and the histopathologic examination

Abstract

Introduction: Fine needle aspiration biopsy (FNAB) of the thyroid nodules generally allows to make the diagnosis and to choose the proper clinical management. In about 10% of cases cytopathologic features do not differentiate unequivocally benign and malignant lesions. In these cases the cytopathologic diagnosis of follicular tumor (FT) or oxyphilic tumor (OT) is most often made.
Materials and methods: From 2001 to 2002 in our Department of Pathology the cytopathologic diagnosis of FT and OT was made in 102 and 25 cases respectively. Histopathologic verification was possible in 39 (38%) patients with FT and in 19 (76%) patients with OT.
Results: Histopathological diagnosis of neoplasm was made in 48.7% (19/39) FT and 42% (8/19) OT. The risk of carcinoma was 12.8% in FT and 16% in OT group (surgical treated cases only).
Conclusions: These results show how difficult the diagnostics of follicular lesions in FNAB could be because of the frequent overlapping of the cytological features of benign and malignant lesions. Diagnosis of follicular tumor does not mean carcinoma. Majority lesions are begin non neoplastic on final histopathologic examination. The use of follicular/ oxyphilic tumor in cytological diagnostic instead of follicular neoplasm seems more advisable. However FNAB in the correlation with clinical data may select the patients for the surgical treatment or the further observation.