Histologic features of thyroid gland in a patient with bromide-induced hypothyroidism

A case of a 22-year-old woman with bromide-induced hypothyroidism is presented. There have been no reports dealing with changes in thyroid function and thyroid morphologic characteristics associated with bromide intoxication. The characteristic histologic features of the affected thyroid gland included a marked hyperplasia of follicles lined by tall columnar follicular cells with foci of papillary proliferation and a loss of colloid materials in the follicular lumen. Ultrastructurally, thyroid follicular cells showed a marked dilatation of rough endoplasmic reticulum containing no electron-dense materials. X-ray microanalysis of the thyroid follicular cells revealed the presence of significant amounts of bromide and an absence of iodine. These indicated that severe hypothyroidism in this patient might be related to the accumulation of bromide in the thyroid follicular cells.