[The biological classifications of malignant thyroid tumours (author's transl)]

Carcinomas of the thyroid gland display large pathological and clinical variation. Favourable prognostic factors accompary well-differentiated tumours, whereas poorly differentiated or anaplastic carcinomas tend to invade early and are usually rapidly fatal. Experience has demonstrated the difference in rate of growth, subsequent recurrence and late spread even in identically well-differentiated thyroid carcinomas. Biological difference must be the underlying reason for the clinical difference in behaviour of histologically similar cancers. This report demonstrates the correlation between in vivo radioactive iodine uptake, tumour staging and recurrence-free interval in 30 thyroid carcinomas. The uptake by well-differentiated carcinomas staged T2N0M0 is significantly higher than that by tumours staged T3N1M0, whereas the latter show a higher uptake than those tumours staged T3N1M0. A high tumour uptake rate is correlated with long recurrence-free interval (up to 24 months) within all groups of staging and vice versa.