Neuropathic pain resulting from pelvic masses

摘要

Cancer patients can expect to suffer pain, particularly in the advanced stages of the disease. Optimal pain control is an essential part of cancer management from the time of diagnosis, as pain can interfere with cancer therapy, limits patient function, and negatively impacts quality of life.Pain can result from primary solid tumors of the pelvic organs and other pelvic tissues; from metastatic tumors; or from nodal conglomerates causing mass effect. Bony pelvic tumors may extend into the pelvic cavity. Tumors of neural structures arise in the pelvis. Pain may follow treatment of pelvic masses and other associated problems. Cancer patients may have painful conditions unrelated to their disease. Having a full understanding of the pathophysiology of pain and the ability to make a pain "diagnosis" are essential to effective pain management.One of the more challenging aspects of cancer pain management is neuropathic pain, that is, the particular type of pain related to nervous system dysfunction. Neuropathic pain may be due to mass compression or traction of nerve structures, which in the pelvis includes irritation of a single nerve or multiple nerves, tumor infiltration of the lumbo-sacral plexus in the pelvic sidewall, or a presacral mass affecting the sacral plexus. Initially, non-neural tumors will cause inflammation of nerves and nociceptive nerve pain, conditions that if not addressed will, over time, progress to nerve damage and the deafferentation type of neuropathic pain. At this point in the process, pain is accompanied by neurologic deficits.Pain can be felt by the patient at the site of tumor, or it may refer to another location in somatic referral patterns, or along nerve root patterns (radicular) or in a non-radicular pattern, or it may have combined features. A critical differential diagnosis for pelvic tumor-related neuropathic pain is compression of the conus medullaris of the spinal cord, resulting in pain and sensory loss in the saddle area (buttocks and perineum) but without lower-extremity symptoms or signs.