According to a study, perineurioma can be divided into 2 forms: intraneural and extraneural (soft tissue) perineurioma. The tumor cells in perineurioma are characterized by their specific immunohistochemical and ultrastructural features. According to the location, to date, approximately 120 cases with intraneural perineurioma have been published. However, the anesthetic management for a parturient with intraneural perineurioma has not been reported. As the spinal roots and nerves of extremities are involved, neuraxial anesthesia should be theoretically avoided. Therefore, general anesthesia may be a safer option.
Perineuriomas are benign peripheral nerve sheath neoplasms composed of perineurial cells. They have been traditionally classified into 2 main types according to their location—intraneural and extraneural and overlap histologically with many other tumors. Intraneural perineurioma is composed exclusively of perineurial cells restricted to the boundaries of a nerve and this term was proposed by Emory et al to combine lesions previously classified as localized hypertrophic neuropathy, hypertrophic mononeuropathy, localized hypertrophic neurofibrosis, intraneural neurofibroma, and hypertrophic interstitial neuritis.
The typical age of onset of intraneural perineurioma is adolescence or young adulthood without sexual predilection. It primarily affects the extremities with associated motor deficiency and occasional sensory loss. The process is usually limited to a single major nerve. It has rarely been described in multiple nerves like our case. The nature of intraneural perineurioma was still a subject of debate. The literatures suggest that the long arm of chromosome 22 contains a tumor suppressor gene involved in the pathogenesis of nerve sheath tumors.
The finding of deletion of 22q11-qter is of particular interest in that same clonal chromosome abnormality has been described in benign and malignant schwannomas, neurofibromas, meningiomas, and gliomas. Although anesthetic management of patients with intraneural perineurioma has not been specifically addressed, surgical removal of intraneural perineurioma arising in the brachial plexus is reported under general anesthesia. The mechanism is likely related to stretch or compression injury to the lumbosacral plexus or lower extremity peripheral nerves.
Compression of the neurovascular supply is another possible mechanism. Moreover, women often push during the second stage of labor in a lithotomy position with their thighs hyperflexed on the abdomen. This position may stretch nerves as they course from the pelvis to the lower extremities. For anesthesiologists, the decision to avoid neuraxial anesthesia was guided by enlarged spinal roots and lumbosacral nerves that make it difficult to perform neuraxial anesthesia, In addition, neuraxial anesthesia may cause direct neurologic injury and secondary injury to nervous system due to the potential risk of bleeding from perineurioma.
In conclusion, the management of a parturient with intraneural perineurioma with careful preconception care and multidisciplinary assessment warranted the optimal reproductive outcomes. Early consultation with anesthesiologists, neurologists, and obstetricians allows the risks to reduce due to the mode of delivery and anesthetic options. Cesarean section under general anesthesia may be the safest option for delivery in a parturient with intraneural perineurioma.