Total thyroidectomy with systematic central lymph node dissection is considered gold standard for medullary thyroid carcinoma and is recommended in European guidelines. In our experience, however, solitary sporadic MTC without clinical lymph node metastases can safely be treated by hemithyroidectomy.

Prospective registration of clinical, biochemical, and pathological data of 10 consecutive patients (8 female, median age 48, range 21-82) treated for MTC with hemithyroidectomy since Nov 2011.

All patients were investigated due to a palpable nodule in the thyroid. Six of 10 patients with unknown serum calcitonin were operated with hemithyroidectomy in diagnostic intension to clarify follicular neoplasia (Bethesda 4) on preoperative cytology, three in our own institution and three outside tertiary care. Four of 10 patients were operated due to thyroid nodules in the presence of elevated serum calcitonin 96 pmol/l [13-2700] (mean, range) but in the absence of lymph node metastases on preoperative cervical ultrasound. Histological tumor size in all patients was 20 mm [6-55]. In one patient one central lymph node metastasis was observed. RET-analysis was negative in all patients. Calcitonin postoperatively was negative (< 0.6 pmol/l) during median follow-up of 92.5 months [1-144] in all patients.

In case of localized disease, sporadic MTC can be safely treated with hemithyroidectomy and ipsilateral central lymph node dissection avoiding hypothyroidism, hypoparathyroidism, and lowering the risk of vocal cord paralysis.