UNILATERAL LOBECTOMY FOR HURTHLE CELL ADENOMA

Considerable controversy exists regarding the ability to predict the b iologic behavior of Hurthle cell tumors. Some have found the clinicopa thologic criteria used to differentiate benign from malignant lesions to be unreliable and have advocated total thyroidectomy for all Hurthl e cell neoplasms. From January 1980 to December 1995, 39 patients had surgery for Hurthle cell tumors of the thyroid. The surgical pathologi c findings were reviewed by an experienced pathologist (TP). Eight pat ients had histologic findings of capsular or vascular invasion consist ent with carcinoma and had total thyroidectomy. Four of these patients had postoperative evidence of residual disease and were treated by ra diation ablation. No evidence of invasion was found in 31 patients dia gnosed with Hurthle cell adenoma. Twenty-three of these patients had u nilateral lobectomy; total thyroidectomy was done in the remaining 8 p atients, 5 of whom were found to have an associated papillary carcinom a at the time of operation. There were no operative deaths or signific ant morbidity. Twenty-two adenomas (71%) were found in females, wherea s males had malignant tumors in 6 of 8 cases (P = 0.025). The mean age of adenoma patients is 54.1 years, and that of the carcinoma patients is 55.8 years, Mean size of benign tumors was 2.8 cm and of malignant tumors 4.1 cm (P = 0.04). Four of seven (57%) carcinomas were larger than 4 cm as compared with 6 of 30 (20%) adenomas (P = 0.069). Follow- up has ranged from 1 month to 15 years, with a mean of 3.2 years. Ther e have been no deaths, and no patients with Hurthle cell adenoma have had evidence of recurrence or metastases during follow-up. Our data su ggest that carcinoma patients tend to be male and tumor size is larger . An association was found when trying to predict malignancy by using 4 cm as a threshold size. We conclude that pathologic evidence of caps ular or angioinvasion can accurately differentiate benign from maligna nt tumors. Unilateral thyroid lobectomy is adequate therapy for the tr eatment of Hurthle cell adenoma, with total thyroidectomy reserved for those patients with histologically proven carcinoma.