[Thyroid microcarcinoma with a fatal outcome and 34 other unusually aggressive cases reported in the literature].

A follicular thyroid microcarcinoma was revealed by scapular metastases. Despite treatment, other metastases were the cause of death after a course of 14 years. In the medical literature there are at least thirty-four other examples of follicular or papillary carcinoma of less than 15 mm (previously called occult) that have either given rise to blood-born metastases or have been the cause of death. Present data from light and electron microscopy, immunohistochemistry and microspectrophotometry cannot differentiate between small and large carcinomas. Microcarcinomas (particularly papillary ones) are frequent in the general population and are found in 5% of thyroids. They are usually not aggressive. Those which show vascular or capsular invasion, a lack of lymphoid infiltrate and large cervical lymph node metastases are more likely to have an unfavorable course. The discovery of a microcarcinoma in a thyroid cells for an extended follow-up.