[DNA cytophotometry of oxyphilic thyroid tumors]

Paraffin-embedded surgical specimen from 47 Hürthle cell tumours of the thyroid gland were examined for DNA content by image cytometry to assess the diagnostic and prognostic utility of ploidy determination in oxyphilic tumors. Both adenomas (31 cases) and carcinomas (16 cases) were studied. As a control for the algorithm of DNA-interpretation, 10 randomly selected normal thyroid tissues were analysed. All control cases showed normal diploid DNA content. Among the Hürthle cell tumours, aneuploid peaks were present in 15 adenomas (48%) and in 13 carcinomas (81%). These findings demonstrate a limited value of aneuploidy as diagnostic feature for malignancy in Hürthle cell tumours of the thyroid. In view of prognosis, there is no unfavourable predictive prognostic value for abnormal DNA content in histologically benign Hürthle cell tumours. No metastases or recurrences occurred in this group during a mean follow up period of 4.4 years. Three patients with aneuploid carcinomas and local recurrences or metastases had higher levels of basic DNA indices. This suggests that aneuploidy has a prognostic value for histologically defined carcinomas.