An interdepartmental collaboration restored a young woman’s quality of life and ability to walk after laparoscopic removal of a rare benign tumor of neurological origin in the lesser pelvis, known as a schwannoma. In the Central and Eastern European region, only the Neuropelvicology Program of the Department of Obstetrics and Gynecology at Semmelweis University and its collaborative group with the Department of Neurosurgery and Neurointervention perform procedures with intraoperative electrophysiological monitoring. Collaboration between the two departments will also be facilitated by a newly acquired specialized mobile neuromonitoring device. The patient made a full recovery and was discharged from the university the day after the successful surgery.
On May 6, 2026, a surgery that attracted great international attention was performed at the Department of Obstetrics and Gynecology at Semmelweis University. This event also marked a new stage in the collaboration between the Department of Histology and the Department of Neurosurgery and Neurointervention. A rare benign tumor originating from the sheath of a peripheral nerve, known as a schwannoma, was removed from the small pelvis of a young woman by the department’s neuropelvicology team, in close collaboration with the neurosurgery and intraoperative neurophysiology working group, led by Dr. Roland Herche, director of neurosurgery and neurointerventions, and electrophysiologist Dr. Boglarka. Haynal and neurology resident Dr. Borbala Damo-Chorba.
“In this case, we encountered a very rare variant of schwannoma, a tumor that grows in the retroperitoneal space behind the uterus in the small pelvis and accounts for 1 to 3 percent of all schwannomas,” said Dr. Laurent Herche. As he pointed out, such cases especially require a thorough neurological or spinal surgical evaluation. This is because the severe pain that occurs in these cases (radiating to the sciatic nerve, sacrum, and lower extremities) is the most characteristic of degenerative spinal disease, which is considered a widespread disease, and is usually the cause.
What is a schwannoma or schwannoma?
Schwannomas are slow-growing tumors that arise from the myelin sheaths of nerves and are a rare disease with an incidence of 0.3 to 0.5 per 100,000 people. However, it can occur anywhere in the body with peripheral nerves, including the extremities, nerve plexuses, nerve roots exiting the spine, the auditory nerve, and other cranial nerves. The most common is vestibular schwannoma, a benign tumor of Schwann cells of the 8th cranial nerve, which accounts for 6 to 10 percent of all intracranial tumors.
Associate Professor Attila Bokor, head of the Endometriosis Center and Department of Laparoscopic Surgery in the Department of Obstetrics and Gynecology, said: “In this patient, a five centimeter tumor developed at the back of the uterus, where the nerve exits the sacrum, and was compressing the nerve. The patient sought testing due to unresolved pain that spread to her right leg.” Recognizing that this was a unique clinical picture, located within the small pelvis, and requiring careful attention during the surgery due to the need to preserve the function of sensitive nerves and organs in that area, he asked the surgeons in the Department of Neurosurgery and Neurointerventional Medicine to collaborate with them to provide electrophysiological monitoring during the procedure.
As Dr. Attila Bokor explained, during the approximately five-hour surgery, which took place in the Baros Street Department of Obstetrics and Gynecology, neurosurgeons continuously monitored the surgical site using a nerve monitor connected to 32 channels of electrodes to determine whether the surgical site contained nerve bundles or only the walls of the schwannoma, and whether removing that tissue would cause nerve damage. “From a neurosurgical point of view, the challenge of this surgery was the laparoscopic localization of the tumor, which we managed to overcome thanks to the laparoscopic experience of Dr. Attila Bokor,” said Dr. Roland Herche. By applying nerve stimulation during laparoscopic dissection, the researchers were able to pinpoint the location of nerves running along the surface of the tumor. Therefore, after dissecting the nerve bundles running along the surface of the tumor, the tumor could be removed in several parts.
This significantly increased safety during the surgery, especially since the approximately 5-centimeter-sized tumor had to be removed from an area that is difficult to access and prone to bleeding. ”
Dr. Attila Bokor
An additional challenge to the surgery was that the tumor was not only compressing the nerve of origin, but was also beginning to affect the function of other nerve roots. Additionally, nerves that control the functions of the rectum, bladder, and vagina also pass through this area. As Dr. Attila Bokor pointed out, in addition to eliminating pain and removing tumors, one of the goals of surgery was to preserve these functions, preserve the fertility of the uterus, and avoid neurological damage.
“To facilitate long-term cooperation and ensure the success of joint surgeries, we have also acquired a mobile neuromonitoring device,” added Dr. Laurent Herche. This is especially used to remove endometriosis lesions that affect the nerves of the lesser pelvis. This is because it is necessary to strike a delicate balance between sacrificing some of the nerves that regulate various vital functions by removing the lesion that causes pain, and maintaining those functions. The device is also useful in treating various vascular compressions within the lesser pelvis that have occurred as a result of previous surgery, radiation therapy, or conditions associated with significant fibrosis or inflammation.
“These are rare conditions. We perform two to three such planned surgeries every three months, and we are the only hospital in Hungary and neighboring countries to do so. On a European scale, only one working group in France and Switzerland performs a similar number of neuropelvic surgeries,” added Dr. Attila Bokor. For this very reason, the removal of the schwannoma, which was performed in early May with intraoperative electrophysiological monitoring, generated interest not only within the university. The operation was also broadcast live by experts from Slovenia, Türkiye, Portugal and other countries.
The surgery went as planned, and the patient was discharged the next day. Not only was she free from pain, but she was also free from the risk of leg paralysis. “She is now fully recovered and now only needs to undergo follow-up MRI scans in three months and one year,” added Dr. Laurent Herche.
