Fig. 4

The histopathological images show parathyroid carcinoma in the left inferior of the left thyroid, which consisted of dense growth of chief cells with a fibrous capsule covering the nodule (A HE staining, magnification ×10). HE staining reveals solid growth of chief cells with nuclear pleomorphism and an increased mitotic count (B magnification ×200, C magnification ×400). The evidence of vascular invasion is indicated by immunohistochemical staining for ERG (D magnification ×100). The Ki-67 proliferation index in parathyroid carcinoma exceeded 5% (E magnification ×100). The histopathology of the subcutaneous nodule in the right neck shows scattering of well-circumscribed benign hyperplasia parathyroid tissue in the nodule (F HE, magnification ×20)