Adipose tissue: a normal constituent of the uterine cervical stroma

Mature adipose tissue present in the uterine cervix is not well documented, and believed to represent heterotopic tissue. The purpose of this study was to determine the frequency and histogenesis of adipose tissue in a series of uterine cervix specimens. A total of 100 consecutive cervical loop electrosurgical excision procedure (LEEP) and cone biopsies from patients of mean age 28 years (range: 15 to 57 yr) were examined. The cervix in 30 hysterectomy specimens was also examined. The presence of cervical stromal and parametrial fat, pathologic diagnosis, number of prior cervical biopsies, and prior pregnancies were documented. In a subset, immunohistochemical stains were performed using S-100, and also CD31, CD34, and D2-40 to exclude dilated lymphatics. Mature fat was identified in 17/100 cone/LEEP cases and 2/30 hysterectomy specimens. Fat was located in deep cervical stroma among large vessels in 15/19 (79%) of these cases, and superficially beneath the mucosa admixed with endocervical glands in 4/19 (21%) cases. Patients with cervical fat in cone/LEEP specimens were of mean age 36 years (range: 21 to 57 yr), of which 65% had a squamous intraepithelial lesion and 35% reactive cervicitis. Those with cervical fat in cone/LEEP tissue had on average 2 prior cervical biopsies/case (range: 0 to 5), compared with 1.7 biopsies/case (range: 0 to 10) in those without identifiable fat. These patients with cervical fat had 1 pregnancy/case, whereas those without had 1.7 pregnancies/case. Mature adipose tissue is a normal stromal constituent of the uterine cervix, which may be identified in up to 15% of excision specimens. The presence of cervical fat seems to be unrelated to patient age, parity, parametrial adipose tissue, inflammation, or prior trauma.