Our study presents a clear cutoff to determine the practicality of using parafibromin, APC, and MIB-1 as immunohistochemical markers to differentiate between PCs and PAs.
Moreover, the findings of positive parafibromin and APC immunoreactivity as well as a low MIB-1 proliferation index and absence of histopathological features of malignancy/atypical adenoma indicate that the parathyroid adenomas arising in these patients did not harbor malignant potential.