Thyroid microcarcinoma and multinodular struma. Personal experience and considerations regarding surgical therapy

Thyroid microcarcinoma is a malignant papillary tumour of the thyroid gland measuring < or = 1.0 cm in diameter. Prognosis and treatment are controversial. We report on a personal series of 28 cases of thyroid microcarcinoma observed over the period from 2000 to 2004. From 2000 to 2004, 199 consecutive total thyroidectomies were performed in patients with multinodular struma. The histological diagnosis was made by a pathologist according to the recommendations of the World Health Organization by means of sections of the thyroid gland of no more than 2 mm. At routine histological examination, 28 cases (14.07%) of "incidental" thyroid microcarcinoma were found. The mean tumour size was 4.10 mm (range: 0.12 to 10 mm). The tumours were multifocal in 2 patients, and none presented lymph node metastases. Thyoid microcarcinoma is a malignant tumour associated with a good prognosis. Multifocality should be the main factor considered in selecting the type of thyroid surgery. A total thyroidectomy may be regarded as sufficient treatment.