Clinicopathological analysis of incidentally detected blue nevi of the uterine cervix in biopsy and curettage specimens. A report of 7 cases.

Abstract

Background & Objectives: Blue nevi (BN) of the uterine cervix (UC) are rare incidental lesions; they are often found in hysterectomy specimens from middle-aged women, or rarely in specimens obtained during more conservative diagnostic procedures (e.g. biopsy, curettage). The objective of our study was to analyse the clinicopathological features of 7 incidentally detected cases of the BN of the UC in biopsy or curettage specimens. Methods: Among a total of 60 BN of the UC diagnosed on operative and biopsy specimens in our Department between 2000-2019, in 7 (7/60, 11.7%) cases BN were found in biopsy or curettage specimens that had been taken for an examination of a clinically or cytologically suspicious cervical lesion (3/7, 42.9%) or a dysfunctional uterine bleeding (4/7, 57.1%), respectively. The mean age of the patients was 44 years (range, 29-57 years). In addition to routine hematoxylin&eosin, histochemical and immunohistochemical stainings were also performed. Results: Histologically, all cases showed loose aggregates of pigmented, spindle-shaped, dendritic or nevoid, epithelioid cells in the superficial stroma in one (4/7, 57.1%) or >2 fragments of cervical mucosa (3/7, 42.9%). The lesions ranged in size from 0.5 to 6mm (mean, 2.4mm), while their thickness ranged between 0.5-4mm (mean, 1.5mm). In one case the BN was presenting as an endocervical polyp. The pigmented cells in all tested cases were positive for melanin (Fontana-Masson), S100, Melan-A, as well as for HMB45 in 3 cases. Conclusion: Although the BN of the UC seem to be lesions of low clinical significance, they require careful differential diagnosis with other pigmented lesions including malignant melanoma, especially because they are rarely detected and might easily be missed or misinterpreted in scanty endocervical curettage or cervical biopsy specimens due to their small size, more frequent endocervical localization and occasional discrete findings.