A. Franco1, J. C. Farrá1,2, O. Picado Roque1, A. R. Marcadis1, R. Teo1, W. Ouyang1, S. Liu1, J. I. Lew1,2 1University Of Miami,Endocrine Surgery,Miami, FL, USA 2Sylvester Comprehensive Cancer Center,Miami, FL, USA
Introduction: The incidence of occult thyroid malignancy in patients undergoing surgery for benign thyroid conditions has been shown to be higher than expected. There may be a risk of missing thyroid carcinomas in patients who do not undergo surgical management of their disease. This study examines the association between benign indication for total thyroidectomy and the finding of thyroid cancer on final pathology.
Methods: A retrospective study of prospectively collected data of 761 patients undergoing partial or complete thyroidectomies at a tertiary referral center was performed. Data collected included demographic characteristics, reason for referral, symptoms, preoperative imaging, FNA cytology, and final pathology results. The reason for referral was stratified into benign and malignant disease. Final pathology was examined for both malignancy in the index nodule as well as incidental malignancy independent of the index nodule. Multivariate logistic regression was used to assess the effect of reason for referral on the odds of having cancer on final pathology.
Results: Of 761 patients who underwent thyroidectomy, 301 were referred for benign disease and 460 for malignancy. Of 301 cases referred for benign disease, 89 were found to have malignancy on final pathology (30%). These 89 cases included 33 that had a malignant index nodule, 34 with incidental malignancy, and 22 in which both an index nodule malignancy and incidental malignancy were found on final pathology. The rates of malignancy according to reason for referral were as follows: 10% (4/40) for Grave’s Disease, 32% (60/189) for non-toxic multinodular goiter (MNG), 49% (18/37) for non-toxic solitary nodule, 19% (4.21) for toxic MNG, and 21% (3/14) for substernal goiter. Of patients with benign thyroid disease and underlying malignancy, 73% had follicular variant papillary thyroid cancer (PTC) (n=65), 16% classical variant PTC (n=14), 2% tall cell variant PTC (n=2), and 2% diffuse sclerosing variant PTC (n=2), 5% follicular carcinoma (n=4), 1% medullary thyroid cancer (n=1), and 1% anaplastic thyroid cancer (n=1) on final pathology. On multivariate analysis, patients with non-toxic MNG had an increased odds of incidental thyroid malignancy on final pathology (OR= 2.7, p <0.01). Patients with Grave’s Disease had a decreased risk of thyroid malignancy on final pathology (OR= 0.19, p <0.01).
Conclusion: Patients operated on for benign thyroid disease have clinically significant rates of underlying malignancy on final pathology. Careful evaluation and counseling by a surgeon is necessary in the management of these patients. Total thyroidectomy remains an important surgical option for patients with multinodular goiters.