Abstract
A thyroid nodule discovered during imaging study performed due to unrelated thyroid disease is known as a thyroid incidentaloma, while positron emission tomography (PET) associated incidental neoplasm of thyroid is known as a "PAIN" phenomenon.To evaluate which patients with "PAIN" phenomenon should undergo surgery in regards to cytology results.Retrospective review of 4716 patients consecutively admitted and surgically treated in tertiary surgical center. 49 (1.04%) patients with "PAIN" phenomenon were identified. All of them had ultrasound-guided fine needle aspiration biopsy (UG-FNAB) performed and cytological results were evaluated according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Patients were divided into 2 subgroups according to histopathological diagnosis: group 1 (n = 25) with benign tumor and group 2 (n = 24) with thyroid cancer.Cytology results were the significant predictors of cancer occurrence in patients with "PAIN" phenomenon (P < .0001). Logistic regression analysis confirmed that category III or higher of TBSRTC in patients with "PAIN" phenomenon significantly increased the risk of cancer (OR = 168.7, P < .0001).Patients with "PAIN" phenomenon and cytology assigned to category III or higher of the Bethesda system should undergo surgery due to significant risk of thyroid malignancy.