Micronuclei studied in fine needle goitre aspirates

Small nuclei at the size level of 1--3 mu--micronuclei--were studied in fine needle goitre aspirates. The greatest frequency of such structures was found in carcinomas, toxic goitres, and lymphoid thyroiditis, but even in the cases where they were found in greatest numbers, these structures comprised only a few promille of the nuclei. The possible significance of the micronuclei, especially with regard to carcinogenesis, is discussed.