Immunohistochemical localization of nerve fibers in the pseudocapsule of fibroids.

The pseudocapsule surrounding fibroids consists of compressed myometrium containing nerves and blood vessels that continue into adjacent myometrium. Oxytocin (OXT) is thought to affect wound healing after myomectomy. We determined the presence of OXT and protein gene product 9.5 (PGP9.5) immunoreactive nerve fibers in pseudocapsule compared to adjacent myometrium. Samples (N=106) of pseudocapsule and adjacent myometrium were collected from 57 women with uterine fibroids undergoing myomectomy, and stained with anti-OXT and PGP 9.5 antibodies to demonstrate the presence of nerve fibers. Nerve fibers in the pseudocapsule stained positively with OXT (89/106, 84.0%) and PGP 9.5 (94/106, 88.7%). The densities of nerve fibers staining with PGP 9.5 and OXT in the pseudocapsule were highest in the isthmus (23.68±22.45/mm2 and 43.35±40.74/mm2, respectively). There were no significant differences in the density of nerve fibers, stained with either OXT or PGP 9.5, between the pseudocapsule, and adjacent normal myometrium regardless of the fibroid location in the uterus (P>0.05). These results suggest that the pseudocapsule should avoid to be damaged during the myomectomy procedure.