[On problems of the term "atypical adenoma" of the thyroid gland (author's transl)].

Besides a separation of reactive-hyperplastic nodules from true adenomas in the sense of autonomic tumours of the thyroid gland "follicular neoplasias" often make difficulties in the daily diagnostic work. This collective term integrates the follicular adenoma and the follicular carcinoma of the WHO-Classification of thyroid tumours (1974). The distinction between a benign "simple adenoma" and an even benign "atypical adenoma", between encapsulated well-differentiated follicular carcinoma and differentiated follicular carcinoma with wide infiltration of the capsule besides other less differentiated follicular carcinomas is very useful. In spite of the good prognosis of the atypical adenoma, clinicans should know the special problems of these tumours and provide a very careful post operationem control.