Lobectomy in follicular thyroid neoplasms' treatment

The purpose of this study is to evaluate the suitability of lobectomy with isthmectomy (LwI) in treatment of Follicular Thyroid Neoplasms (FTN), considering malignancy incidence and postoperative complications.

192 patients (165 females; 27 males) who underwent LwI for FTN from 01/2005 to 12/2007 were retrospectively evaluated: clinical and pathological features, surgical complications and five year outcome. Inclusion criteria were cytological Bethesda category III and IV or histological follicular adenoma/carcinoma or follicular variant of papillary carcinoma). Metastatic disease or previous thyroidal surgery patients were excluded.

Mean age was 48.68 ± 14.93 yrs. Overall malignancy occurred in 88 patients (45.83%) and 80 (41.67%) underwent thyroidectomy completion (TC), mainly by index lesion's malignancy. Forty-one (21.35%) in LwI and 31 (38.75%) in TC specimens had associated malignancy, mainly papillary microcarcinomas. High preoperative Thyroid-Stimulating Hormone (TSH), histological multinodularity and, in cytology category IV, younger age, were significantly associated to malignancy. Permanent recurrent laryngeal nerve lesion occurred in 0.58% in Lwl and 1.52% in TC, and temporary dysphonia occurred in 9.25% and 6.06% (LwI and TC respectively). No LwI patients presented hypoparathyroidism whereas 3.03% in TC had temporary symptoms. In LwI, 36.70% developed hypothyroidism. Higher preoperative TSH was associated with hypothyroidism development.

LwI was inappropriate in 40.10% patients with malignancy who required TC and 23.12% had no functional benefit because post-LwI hypothyroidism. Nodular relapse was reported in at least 23/113 LwI patients (20.35%). We propose total thyroidectomy for patients with FTN preoperative TSH higher than 2.16 mU/L and, in Bethesda category IV, less than 39.5yrs.