Presence of nuclear grooves in endometrial cytology

Although the presence of nuclear grooving in papillary carcinomas of the thyroid has been well-described, so far the attention paid to similar structures in endometrial cell samples has been limited. In order to investigate the occurrence of nuclear grooves in endometrial specimens from patients with various pathologic conditions of the endometrium, we compared their appearance with papillary thyroid cancers. A total of 10 cases was studied (age range, 40-72 yr), all cases demonstrating nuclear grooves. In each case, 10 random high-power fields (HPFs) were investigated, and the numbers of fields in which nuclear grooving could be seen were recorded. Nuclear grooves were observed in 3-36 of each HPFs and were more often observed in atypical endometrial cells than in their normal-appearing counterparts; however, these nuclear alterations were thought to be nonspecific findings.