Blue nevus of the endocervix.

The mucosa of the uterine cervix is normally devoid of melanocytes; therefore, melanin-containing lesions are very rare in this site. A new case of a common blue nevus in the cervix of a 57-year-old woman is reported. The lesion was an incidental finding in a total hysterectomy specimen performed for atypical endometrial hyperplasia. Gross and histological examination revealed minute dark macula on the mucosa of the posterior aspect of the endocervical canal, composed of loose conglomerates of spindle-shaped and dendritic cells located superficially within the stroma, containing multiple brownish granules, which exhibited positive immunostaining for HMB45 and melan A. Although the blue nevi seem to be lesions of low clinical significance, they require careful differential diagnosis with malignant melanoma, especially in scanty endocervical curettage or cervical biopsy specimens.