Postablation neuroma of the myometrium-a report of 5 cases

When hysterectomy is performed for chronic pelvic pain, routine pathology examination often provides no explanation. However, analysis of small uterine nerves using immunostains may help to address this deficiency. Small uterine nerves tend to be sparse or absent in wide areas of normal myometrium. Some studies of uterine nerves have suggested that endometriosis, adenomyosis, and fibroids are not inherently painful, with increased small nerves in the inner uterine wall associated with the history of pelvic pain. Although such areas may appear normal on hematoxylin and eosin (H&E), we have found a subtle inner wall lesion termed inner myometrial elastosis, best detected with trichrome or elastic stains, which may be a reaction to microscopic tears of inner myometrium. Such tears may induce increased inner wall innervation via the generation of nerve growth factor in granulation tissue. In the course of studying uterine nerves with immunostains, we found 5 cases with florid nerve proliferation, after deep endometrial ablation for abnormal uterine bleeding led to increased pelvic pain. We suggest that immunostains for postablation neuromas should be done in hysterectomies when pelvic pain increases after endometrial ablation. This may offer gynecologists and their patients an objective finding with a rational, scientific explanation for the pelvic pain.