Risk of malignancy in the non-dominant thyroid nodule

Abstract

Purpose. The purpose of this study was to assess how frequently thyroid cancer is located only in the non-dominant nodules. Methods. A total of 111 thyroid patients, whose primary operation were carried out at our institute and were confirmed to have thyroid cancer, were evaluated. Tumor characteristics were recorded in a retrospective database. Variables analyzed included patients’ age and sex, nodule and tumor size, ultrasound features of nodules, fine needle aspiration biopsy result and the presence of multifocality of malignancy. Results. There were 91 females and 20 males. Mean age was 48±12 years (range 16-80 years). Mean dominant nodule size was 2.1±1.3 cm, while mean malignant tumor size was 1.4±1.4 cm (range 0.1-7 cm). Carcinomas were located in the dominant nodule in 61 (55%) cases, while it was present in the non-dominant nodules – without a neoplastic focus in the dominant nodule – in 50 (45%) cases. In 20 (18%) cases the carcinoma was found in both the dominant and the non-dominant nodule. Multifocality of the malignant tumor was present in 64/111 (58%) cases. Conclusions. Risk of malignancy in the non-dominant thyroid nodule should be kept in mind before carrying out a biopsy from the dominant nodule. Assessment of multinodular goiter should not be restricted to the dominant nodule.