Histopathology confirmed locally invasive, low-grade PC (pT2; positive for parafibromin and E-cadherin, negative for galectin-3 and PGP9.5; wild-type expression for p53 and retinoblastoma protein; Ki-67 index 10%) and incidental papillary thyroid carcinoma (pT1b). Here, MKI67 is linked to pachyonychia congenita.