H&E stained section of affected parathyroid gland (x100). A parathyroid gland is shown, invaded from a follicular thyroid carcinoma. Malignant cells are large, composed of eosinophilic cytoplasm and round nuclei. These tumor cells form groups or scant follicles with parathyroid cells and lipocytes among them. At the periphery of this picture the parathyroid capsule is shown.