Factors that predict malignant thyroid lesions when fine-needle aspiration is ''suspicious for follicular neoplasm''

Objective: To assess clinical factors that may improve the ability to predict the presence of a malignant lesion in thyroid nodules that are found to be ''suspicious for follicular neoplasm'' by fine-needle aspiration (FNA) cytology. Material and Methods: We undertook a retrospective review of the medical records of all patients at the three Mayo Clinic facilities who underwent a thyroid surgical procedure between January 1992 and December 1994 and had a preoperative FNA report of ''suspicious for follicular neoplasm,'' Patient and nodule characteristics were analyzed statistically for associations with the presence of cancer. Results: The study cohort consisted of 219 patients with a mean age of 54.3 years, Eighty-four percent of resections were done for benign disease. Of the 35 malignant lesions, 9 were incidental papillary cancers separate from the primary nodule; thus, only 26 cancers were found in the index nodule, and only 19 (9% of the total group) were follicular carcinomas, Clinical findings associated with a malignant index nodule were larger diameter, fixation of the mass, and younger age of the patient. Conclusion: Clinical characteristics may be used for more accurate assessment of the risk of the presence of a malignant lesion when FNA cytology of a thyroid nodule is reported as ''suspicious for follicular neoplasm.''.