The aim of this study was to compare the clinicopathological features of Hürthle cell carcinomas (HCC) and oncocytic papillary thyroid carcinomas (OPTC) and to evaluate their response to radioactive iodine (RAI) treatment.
We retrospectively reviewed the charts of patients with histopathologically verified OPTC (group 1) and HCC (group 2), during a 17-year period. All patients underwent total thyroidectomy and received RAI adjuvant therapy. Clinicopathological characteristics of the two groups were compared. Response to initial therapy was assessed 6 to 24 months after RAI ablation according to the American Thyroid Association dynamic risk reclassification. Clinical outcomes were evaluated.
A total of 28 patients (8 OPTC and 20 HCC) were included. There was no significant difference in clinicopathological features including sex, age, tumour size and vascular invasion. Distant metastases were absent in both groups. OPTC, however, presented more features of local invasion (50% vs. 10%, P = 0.03), extrathyroidal extension (25% vs. 0%, P = 0.07) and lymph node involvement (37.5% vs. 0%, P = 0.01). Median cumulative RAI activity administered to both groups was 200 mCi (range: 100–300 mCi). Response to RAI therapy was excellent in all HCC and 87.5% of OPTC (P = 0.28). One patient with OPTC (12.5%) presented an indeterminate response. Clinical outcomes were favourable after a median follow-up of 87.5 and 49 months, respectively.
Although OPTC presented more locoregional invasion, clinicopathological characteristics of OPTC and HCC were comparable. Both OPTC and HCC were iodine responsive. We suggest that adjuvant RAI therapy after total thyroidectomy is beneficial for OPTC and HCC and may improve disease-free survival.
Departments of aNuclear Medicine
bPathology, Habib Bourguiba Hospital, Sfax, Tunisia
Received 19 February 2019 Accepted 30 May 2019
Correspondence to Dr Wissem Amouri, Department of Nuclear Medicine, Habib Bourguiba Hospital, Sfax, Tunisia, Tel: + 216 53 841 661; fax: + 216 74 243 427; e-mail: email@example.com