Uterine innervation in adenomyosis.

This study describes the innervation of the uterus with a histopathological diagnosis of adenomyosis in a retrospective survey of two groups of uteri. Group 1 consisted of 17 histologically-normal, parous uteri and eight nulliparous uteri. Group 2 consisted of 23 parous uteri with the histopathological diagnosis of adenomyosis. Tissue sections from the uterine isthmus were stained for nerves with PGP 9.5 using a standard immunohistochemical regimen. In group 1 (n = 25, normal histological report), normal innervation of the uterine isthmus included concentrations of nerves in the subserosal layers and at the endometrial-myometrial interface with sparse, neurovascular bundles distributed throughout the myometrial stroma. In group 2, (n = 23 with adenomyosis), there were no nerves in areas of adenomyosis and absence of nerves at the endometrial-myometrial nerve plexus. Focal proliferation of small-diameter nerve fibres was observed at the margins of adenomyosis in some uteri. Subserosal nerve fibres were still present in those sections that extended to include this region. Adenomyosis is associated with loss of nerve fibres at the endometrial-myometrial interface and absence of nerve fibres in the adenomyosis.