AMACR and Epidermal Inclusion Cyst: On the endometrial polyp surface and adjacently to CC-EIC, there was a proliferation of atypical cells that shared cytological and immunophenotypical features with CC-EIC (including the aberrant p53 pattern) but lacked the papillary architecture and the expression of Napsin A and AMACR; these features suggested that such lesion might represent a high-grade precancerous lesion of CC-EC (Table 1).