Schwannoma, also known as neurilemmoma or Schwann cell tumor, is one of the most common neoplasms of the nerve sheath which usually appears at the head, neck, or upper extremity. Schwannoma occurrence in the lower extremity originating from the common peroneal nerve is rarely reported according to literary findings. We report a case of a 32-year-old man who presented with a 6-month history of a growing lump in the left knee. MRT revealed a well-defined 9.6 cm × 7.8 cm × 6.5 cm multilobular mass of heterogeneous consistency with areas of necroses with a likely diagnosis of synovial sarcoma. After surgery, a final histopathological assessment of the tumor demonstrated Antoni A and B patterns with nuclear palisading, hallmarks of a schwannoma. Postoperatively the patient suffered a neurological complication-impaired dorsiflexion of the left foot. The patient started immediate physiotherapy in the Department of Rehabilitation. Three weeks after the operation, gradual improvement in neurological function was observed. To date, complete tumor excision combined with microscopic analysis and immunohistochemical staining remains the gold standard in diagnosing and treating a peripheral nerve schwannoma. Moreover, the use of additional nerve monitoring tools during surgery could help to prevent complications.

Posterior interosseous nerve syndrome is the most frequent syndrome of radial nerve compression, with the arcade of Frohse being the main site of compression. Its symptoms include difficulties in finger and wrist extension with possible radial deviation. Herein, we present a case of posterior interosseous syndrome caused by a schwannoma, a type of neurological tumor.

暂无摘要。

The blood vessel lumen is an extremely rare location for a benign peripheral nerve sheath tumor like schwannoma. Less than 10 cases have been previously reported. In this report, we present a case of a 68-year-old woman who had a soft tissue nodule at the posterior calf of her left leg during a physical examination. Pathological examination was performed after complete surgical excision. The patient underwent follow-up for 12 months after surgery without evidence of recurrence or any other complication. This is the first case of intravascular schwannoma reported as a cause of vein obstruction. Microscopically, the tumor was composed of Schwann spindle cells that were immunoreactive for S100 protein and SOX10. This tumor was surrounded by a well-defined vascular smooth muscle wall. Prospective series are required to improve the knowledge on the underlying mechanisms of intravascular schwannoma development.

An 8-year-old Portuguese Water Dog presented with a 5-month history of left forelimb lameness. There was palmar pain. Ultrasonography revealed enlargement of the left median nerve. Subsequent MRI also showed enlargement of the median nerve in the distal palmar to the mid-forearm region. Rapid intraoperative diagnosis suggested malignant peripheral nerve sheath tumors (MPNST) and a neurotomy was performed. The lameness had almost disappeared in 1 month after surgery. Recurrence occurred 26 months postoperatively and the forelimb was amputated. At 950 days after the neurotomy, radiography revealed lung metastasis, and the dog died 988 days after the neurotomy. Neurotomy for MPNST should be performed with caution until more information is available regarding methods for early detection, margin determination, and indication determination for neurotomy.

This case report describes the treatment of a postoperative painful neuroma of the tibial nerve using an autologous nerve graft in a dog. The patient presented with sudden non-weight-bearing lameness 10 days after iatrogenic tibial nerve injury during preparation of a reverse saphenous conduit flap. The dog showed severe pain at the surgical site without nerve deficits. A magnetic resonance imaging examination revealed an enlarged tibial nerve at the injury site, consistent with a neuroma. Analgesics were administered over 11 days, but the patient remained in severe pain and non-weight-bearing. Therefore, surgical resection was recommended. The fusiform neuroma was resected microsurgically, and a saphenous nerve graft was transplanted using an epineural nerve repair technique. Histopathological examination was consistent with a neuroma. The dog showed immediate pain relief and weight-bearing the day after surgery with normal motor function. The dog made a full recovery by the last follow-up 6 mo after surgery. If patients develop pain and lameness following surgery or nerve injury, neuroma formation must be considered, even shortly after surgery. Microsurgical resection and autologous nerve transplantation using an epineural nerve repair technique is a viable method to treat painful neuromas and minimize the risk for recurrence in dogs.

» Tumors of the brachial plexus are uncommon and can present as a mass, with or without neurological symptoms. At times, asymptomatic tumors are also picked up incidentally when imaging is performed for other reasons.» Magnetic resonance imaging is the main imaging modality used to evaluate tumors of the brachial plexus. Other imaging modalities can be used as required.» Benign tumors that are asymptomatic should be observed. Excision can be considered for those that are found to be growing over time.» Biopsies of tumors of the brachial plexus are associated with the risk of nerve injury. Despite this, they should be performed for tumors that are suspected to be malignant before starting definitive treatment.» For malignant tumors, treatment decisions should be discussed at multidisciplinary tumor boards, and include both the oncology and peripheral nerve surgical team, musculoskeletal radiology, neuroradiology, and general radiology.

BACKGROUND: Augmented reality navigation is the one of the navigation technologies that allows computer-generated virtual images to be projected onto a real-world environment. Augmented reality navigation can be used in spinal tumor surgery. However, it is unknown if there are any pitfalls when using this technique.
METHODS: The patient in this report underwent complete resection of a cauda equina tumor at the L2-L3 level using microscope-based augmented reality navigation. Although the registration error of navigation was <1 mm, we found a discrepancy between the augmented reality navigation images and the actual location of the tumor, which we have called \"navigation mismatch\". This mismatch, which was caused by the mobility of the spinal tumor in the dura mater, seems to be one of the pitfalls of augmented reality navigation for spinal tumors.
CONCLUSIONS: Combined use of intraoperative ultrasound and augmented reality navigation seems advisable in such cases. J. Med. Invest. 71 : 174-176, February, 2024.

BACKGROUND: Many surgical strategies aim to treat the symptomatic neuroma of the superficial branch of the radial nerve (SBRN). It is still difficult to treat despite many attempts to reveal a reason for surgical treatment failure. The lateral antebrachial cutaneous nerve (LACN) is known to overlap and communicate with SBRN. Our study aims to determine the frequency of spreading of LACN fibers into SBRN branches through a microscopic dissection to predict where and how often LACN fibers may be involved in SBRN neuroma.
METHODS: Eighty-seven cadaveric forearms were thoroughly dissected. The path of LACN fibers through the SBRN branching was ascertained using microscopic dissection. Distances between the interstyloid line and entry of LACN fibers into the SBRN and emerging and bifurcation points of the SBRN were measured.
RESULTS: The LACN fibers joined the SBRN at a mean distance of 1.7 ± 2.5 cm proximal to the interstyloid line. The SBRN contained fibers from the LACN in 62% of cases. Most commonly, there were LACN fibers within the SBRN\'s third branch (59%), but they were also observed within the first branch, the second branch, and their common trunk (21%, 9.2%, and 22%, respectively). The lowest rate of the LACN fibers was found within the SBRN trunk (6.9%).
CONCLUSIONS: The SBRN contains LACN fibers in almost 2/3 of the cases, therefore, the denervation of both nerves might be required to treat the neuroma. However, the method must be considered based on the particular clinical situation.

The chapter is focused on the neoplastic peripheral nerve lesions, which primarily involve \"cranial and paraspinal nerves,\" as outlined in the CNS volume (WHO_Classification_of_Tumours_Editorial_Board, 2021). These include classic peripheral nerve sheath tumors such as schwannoma, neurofibroma, intraneural perineurioma, and malignant peripheral nerve sheath tumors, with their variants as well as new and more precisely defined entities, including hybrid nerve sheath tumors and malignant melanotic nerve sheath tumor (previously melanotic schwannoma).