[Follicular carcinoma].

Thyroid follicular carcinoma are divided in three subgroups: 1) minimally invasive well differentiated encapsulated follicular carcinoma; 2) invasive well differentiated follicular carcinoma; 3) moderately differentiated follicular carcinoma. Usually diagnosis between encapsulated well differentiated follicular carcinoma and atypical adenoma is difficult. Apart the presence of metastases, histologic criteria to separate these entities are often insufficient. Insofar as all these tumours have a very good prognosis, we think that they could be brought together under the same terminology. Actual morphological differences would be expressed, like in some others localizations, in a histologic grading. This way of classifying appears more consistent with reality and could allow to assume in better conditions, diagnostic uncertainty which exists in this field.