Cytologic and Histologic Observation in Hyperthyroidism Twelve Years after ¹³¹I Therapy

Abstract

This paper has reported the results of histopathological observation of thyroid gland in a 67-year old woman treated with Sodium Iodine 1³¹I (13, 500 rads) for hyperthyroidism 12 years before. The left lobe of thyroid gland was nodular, elastic firm, and enlarged to thumb tip in size. Thyroid scan revealed evidence of selective accumulation of ¹³¹I as hot nodule within the region of the left nodular goiter and outside of the right lower lobe.
Aspiration biopsy smears of the goiter are as follow;
Epithelial cells found in tight cluster and a. few sheets. On M-G-G staining, there were blue-stained coarse granules of various sizes in the cytoplasma. The cell borders were ill-defined. Most of nuclei showed nuclear abnormalities with hyperchromatism and giant atypical forms. Some of nuclei had ill-defined nuclear border and intra-nuclear vacuoles.
Histological findings of goiter revealed follicular adenoma and reduction in the size of the right entire lobe and left one except adenoma. Dense hyaline fibrosis was noted in many areas. In these regions, the follicles were clearly atrophic and lining cells were seen to have large irregular, hyperchromatic nuclei and cytoplasmic vacuoles.
These changes were considered to be consistent with radiation effect due to Sodium Iodine ¹³¹I treatment. Irradiation changes of follicular epithelials should be recognized and differentiated from the ne plastic changes which they resemble, in.needle aspiration biopsy of thyroid gland of patients previously treated with ¹³¹I for hypertyroidism.