Scanning electron microscopy of euthyroid goiter and Graves's disease

The scanning electron microscopy of 5 euthyroid polynodular goiters and 5 cases of Grave's disease was studied. In the polynodular goiter most of the follicular cells were flattened. Small, coarse, irregular microvilli were noticed. In the Grave's disease cases the follicular cells were columnar, covered with long microvilli. Marked epithelial infoldings were found. Thick bundles of collagen surrounded the follicles, especially in the polynodular goiter.