Case Report: Sciatic nerve schwannoma - a rare cause of sciatica

The Rare Large Common Peroneal Nerve's Schwannoma-A Case Report and Literature Review

Schwannoma in the popliteal fossa is still rare, often diagnosed late because it grows slowly and has no symptoms. It is often misdiagnosed with connective tissue tumors or with neurological disorders originating in the spine or disorders of the peroneal nerve. Schwannoma within the common peroneal nerve is still rare in the popliteal fossa, with most tumor sizes around 2 cm in diameter due to their smaller size of nerve but can cause neurologic disturbance, especially when it is large. And over a long time, it can cause serious complaints like neurological deficits and make surgery difficult by leaving greater sequelae. There is no data yet showing the incidence of schwannoma in the common peroneal nerve. In this case, a 36-year-old woman, for 5 years, feels soreness in the popliteal fossa and pain in the right instep, suspected that a nerve was pinched, due to an abnormality in the spine. As time went on, there was a lump in the fold of the right knee, suspected to be a Baker's cyst. As time went by, the complaint was burning pain in the right instep to the lateral ankle and distal right lower leg, disturbing sleep. Tinel's sign was positive. The right instep has hypoesthesia and a slight drop in the foot. On radiological examination of the right knee, a circumferential mass appeared, measuring 5 cm × 4 cm. The diagnosis is suspicious for a common peroneal nerve tumor. The encapsulated operation to remove the tumor was carried out with a size measuring 5 cm × 4.5 cm × 4 cm. The histopathological examination showed schwannoma. After surgery, the pain disappeared, hypoesthesia and a slight drop in the foot underwent physiotherapy, and stimulation with the result gradually improved. A thorough early examination includes correct and systematic anamnesis, physical examination, and neurological evaluation such as paraesthesia, hypoesthesia, and Tinel's sign; also, additional examinations, such as radiographic, ultrasound, and MRI, are needed for early detection of schwannoma so that delays in diagnosis and surgery can be avoided to prevent neurological deficits.

An Unusual Case of a Giant Schwannoma of the Sciatic Nerve: A Case Report With a Review of Literature

Sciatic nerve schwannomas are rare tumors, mainly characterized by sciatic neuralgia rather than sensory-motor deficits. The poorly suggestive clinical presentation of this localization leads to a delayed diagnosis. Here, we describe the case of a 47-year-old female patient with a nine-month history of schwannoma localized in the sciatic nerve, just above the left popliteal fossa. Although magnetic resonance imaging (MRI) is the imaging modality of choice, the final diagnosis rests on the histological examination of the tumor. The schwannoma must be surgically removed without severing the nerve trunk.

Schwannoma of the Sciatic Nerve as a Cause of Extra-articular Knee Pain: Case Report and Literature Review

INTRODUCTION

Schwannomas are rare benign tumors of the nerve sheath that originate from the Schwann cells of the peripheral nerve and have a broad anatomic distribution that includes superficial tissues, deep tissues, including the central nervous system, and the gastrointestinal system.

CASE REPORT

A 60-year-old male presented with left knee pain for 5 years. This pain was associated with paresthesia, night pain unresponsive to analgesia, on the left foot intermittent pins and needles sensation. Schwannoma lesion was excised, histology confirmed the diagnosis, and the patient's symptoms improved.

CONCLUSION

Schwannoma around the knee is a rare or atypical cause of the non-arthritic pain and should be considered in the differential diagnosis of non-arthritic and extra-articular causes of knee pain with neurological deficit of the foot in an adult population.

Plexiform schwannomas of the sciatic nerve:a case report and review of the literature

Background

Schwannomas grow slowly, mainly in the head and spine. The extremities schwannomas are rare and easily missed, particularly in patients who also have lumbar disc herniation in addition to sciatic schwannomas. We present a unique case of sciatic schwannoma , which has been considered as a lumbar disease in the past until an MRI of the thigh.

Case presentation

A 43-year-old female complained of pain in her low back and left thigh for 10 years. Physical examination showed that her left thigh was swollen and positive Tinel sign. On MRI, we found a series of tumors suspected of schwannomas at the back of her left thigh. After obtaining the patient's consent, we performed intracapsular excision of her tumors. Histological examination of the tumors were consistent with plexiform schwannomas. The patient recovered well after operation and there was no sign of nerve injury or recurrence after follow-up for 11 months. We searched the Pubmed database and found 31 published reports about sciatic schwannomas.

Conclusions

Sciatic schwannomas usually occur in middle-aged women, and the main symptom is pain. In addition to palpation, we should pay attention to Tinel sign during physical examination. MRI is very helpful for diagnosis, but histological examination is the only way to make a final diagnosis. Intracapsular resection is the best method for the treatment of schwannomas, although there is still the possibility of recurrence after operation.

Extra-spinal sciatica and sciatica mimics: a scoping review

Not all sciatica-like manifestations are of lumbar spine origin. Some of them are caused at points along the extra-spinal course of the sciatic nerve, making diagnosis difficult for the treating physician and delaying adequate treatment. While evaluating a patient with sciatica, straightforward diagnostic conclusions are impossible without first excluding sciatica mimics. Examples of benign extra-spinal sciatica are: piriformis syndrome, walletosis, quadratus lumborum myofascial pain syndrome, cluneal nerve disorder, and osteitis condensans ilii. In some cases, extra-spinal sciatica may have a catastrophic course when the sciatic nerve is involved in cyclical sciatica, or the piriformis muscle in piriformis pyomyositis. In addition to cases of sciatica with clear spinal or extra-spinal origin, some cases can be a product of both origins; the same could be true for pseudo-sciatica or sciatica mimics, we simply don't know how prevalent extra-spinal sciatica is among total sciatica cases. As treatment regimens differ for spinal, extra-spinal sciatica, and sciatica-mimics, their precise diagnosis will help physicians to make a targeted treatment plan. As published works regarding extra-spinal sciatica and sciatica mimics include only a few case reports and case series, and systematic reviews addressing them are hardly feasible at this stage, a scoping review in the field can be an eye-opener for the scientific community to do larger-scale prospective research.

A rare cause of sciatica: Sciatic nerve schwannoma - Report of one case with long subclinical course and misleading presentation

The authors report one case of schwannoma located in the sciatic nerve, just above the popliteal fossa. A sciatic localization is rare, observed in 1% of the patients. The misleading clinical presentation of this localization causes a delay in diagnosis. Magnetic Resonance Imaging (MRI) is the imaging modality of choice, but the final diagnosis is made by the histological examination of the tumor. Schwannoma should be surgically removed without division of the nerve trunk.

Schwannomas of the sciatic nerve: A rare and neglected diagnosis. A review of the literature with two illustrative cases

OBJECTIVE

Schwannomas of the sciatic nerve, which is the largest nerve of the human body, are very rare accounting for ≤ 1% of all schwannomas. They often may raise confusion with other more common causes of sciatica, such as lumbar degenerative and inflammatory diseases or spinal tumors, which may often lead to a late correct diagnosis.

PATIENTS AND METHODS

We present two cases of sciatic nerve schwannomas that were recently treated at our Institution, and we review the pertinent English literature on this topic over the last 15 years, yielding twenty three cases to analyze.

RESULTS

Even if sciatic nerve schwannomas are a rare occurrence, a thorough clinical and radiological evaluation of the sciatic nerve should be considered whenever a sciatic pain is not otherwise explained. A positive Tinel sign and a palpable mass along the course of the sciatic nerve may be strong clues to achieve the diagnosis. Combined morphological and advanced functional MRI imaging may help to differentiate benign from malignant peripheral nerve sheath tumors, avoiding unnecessary preoperative biopsy.

CONCLUSIONS

A standard microsurgical technique guided by ultrasound and neurophysiologic monitoring, allows in most of the cases a safe removal of the tumor and very satisfactory post-operative results for the patients.

Case Report: Sciatic nerve schwannoma - a rare cause of sciatica

Herein we report a rare case of a sciatic nerve schwannoma causing sciatica in a 69-year-old female. Sciatic nerve schwannoma is a rare entity. It should always be considered as a possible cause of sciatica in patients that present with symptoms of sciatica with no prolapsed disc in the lumbar spine and a negative crossed straight leg raise test. Timely diagnosis and complete excision of the lesion leads to complete resolution of the symptoms of such patients.