[Benign thyroid oncocytomas. Outcome after more than 4 years]

Occasional malignant transformation after partial thyroidectomy for Hürthle cell tumours has led certain authors to propose total thyroidectomy in all cases. The aim of this retrospective study was to evaluate outcome 4 years after partial thyroidectomy in patients with Hürthle cell tumours.

Ten patients (9 females, 1 male; mean age 45 years; age range 21-65 years) underwent thyroid surgery for Hürthle cell tumours from 1980 to 1989. Lobectomy was performed in 7, subtotal thyroidectomy in 2 and tumourectomy in 1. The extemporaneous pathology examination reported 4 apparently benign vesicular lesions, 2 apparently benign oncocyte lesions, 2 fetal adenomas, 1 thyroiditis, 1 trabecular adenocarcinoma. Pathology examination of the surgical specimen reported isolated benign oncocyte tumours in 4 cases and benign oncocyte tumours with associated vesicular adenomas in 5. In 1 case it was not possible to confirm whether the oncocyte lesion was benign or malignant. All 10 patients were seen again 6 months later for consultation and thyroid hormone assays and thyroid echography in doubtful cases.

All patients were seen for follow-up (mean 88 months; range 47-148 months). New thyroid nodules were observed in 2 but did not require surgery. No cervical lymph node enlargement was found.

The diagnosis of Hürthle cell tumour was confirmed intraoperatively in 8 of the 10 cases. No malignant transformation was observed. These findings demonstrate that total thyroidectomy cannot be indicated intraoperatively and would not appear to be indicated after partial thyroidectomy.