Intramuscular schwannoma arising from the psoas muscle presenting with femoral nerve neuropathy

Laparoscopic resection of retroperitoneal intra-psoas muscle schwannoma: A case report and extensive literature review

INTRODUCTION

Soft tissue tumors of Schwann cells in either the peripheral or cranial nerves are known as schwannomas or also as neurilemmomas. Limited data exists regarding psoas muscle schwannoma in the literature. Therefore, we have done an extensive literature review and found a total number of 46 cases of intra-psoas schwannoma including our case, which are summarized in this article along with reporting our new case.

PRESENTATION OF CASE

We report a very rare case of primary left intra-psoas muscle schwannoma in a 39-year-old Saudi gentleman, smoker with an unremarkable medical and surgical history. The patient presented to the emergency department with exacerbated chronic lower abdominal pain since almost 2 years. After conforming the diagnosis, the patient was admitted electively and underwent uneventful laparoscopic hand-assisted resection.

DISCUSSION

Schwannomas are neurogenic tumors which known to be solitary, benign, well circumscribed, encapsulated, and slow-growing tumors. Multiple imaging modalities are used to detect such a tumor. Although there is no consensus on the best surgical approach, endoscopic mini-laparotomy, laparoscopy (anterior [as in our case] or lateral), and robotic resection were reported with good outcomes.

CONCLUSION

Retroperitoneal schwannoma and intra-psoas muscle variant are a rare entity, with slow growing rate and risk of malignant transformation. Therefore, high index of suspicion, good follow-up, and large-cohort studies are encouraged.

Femoral Neuropathy Secondary to Autosomal Dominant Polycystic Kidney Disease: A Case Report

Compressive femoral neuropathy is a disabling condition accompanied by difficulty in hip flexion and knee extension. It may result from retroperitoneal hematoma or bleeding, or from complications associated with pelvic, hip surgery, and renal transplants. A 55-year-old female with autosomal dominant polycystic kidney disease presented with proximal muscle weakness in lower extremities. The patient experienced recurrent renal cyst infection, with aggravated weakness during each event. Electromyography and nerve conduction study revealed bilateral femoral neuropathy. Computed tomography and magnetic resonance images were added to further identify the cause. As a result, a diagnosis of femoral neuropathy caused by enlarged polycystic kidney was made. Cyst infection was managed with antibiotics. Renal function was maintained by frequent regular hemodialysis. While avoiding activities that may increase abdominal pressure, rehabilitation exercises were provided. Motor strength in hip flexion and knee extension improved, and was confirmed via electrodiagnostic studies.

Paraspinal Schwannoma of dorsal ramus nerve: A case report

Spinal Schwannomas are benign nerve sheath tumors and the most common intradural extramedullary tumors of the spine, mainly occurring in the cervical and lumbar region. The location distinct from the spinal canal is very rare. We report a rare case of a 45year old male with Schwannoma in the dorsal paraspinal musculature. Complete surgical excision of the lesion was performed with clear margins and neuropathological analysis revealed a Schwannoma. There has been no recurrence after 6 months.

Successful laparoscopic resection of a retroperitoneal schwannoma arising from the femoral nerve: A case report

We report on a 45-year-old man who presented with pain in the left leg, which he had had for 2 months. A contrast-enhanced CT scan displayed a 25-mm tumor in the lateral side of the left psoas muscle. For this suspected retroperitoneal tumor, we performed laparoscopic resection of the tumor, which was encapsulated by the funicular femoral nerve, using surgical scissors rather than a surgical energy device and preserved the normal fascicles wherever possible. Pathological examination indicated a benign ancient schwannoma arising from the femoral nerve. The patient was able to return to his job 3 weeks after surgery, and he has shown no evidence of recurrence. This was thought to be because of the use of surgical scissors, rather than a surgical energy device, combined with visual magnification. Therefore, the laparoscopic approach is an effective and minimally invasive option for the resection of femoral nerve schwannoma.

Intramuscular schwannoma: clinical and magnetic resonance imaging features

INTRODUCTION

Schwannomas that arise within the muscle plane are called intramuscular schwannomas. The low incidence of these tumours and the lack of specific clinical features make preoperative diagnosis difficult. Herein, we report our experience with intramuscular schwannomas. We present details of the clinical presentation, radiological diagnosis and management of these tumours.

METHODS

Between January 2011 and December 2013, 29 patients were diagnosed and treated for histologically proven schwannoma at the National University Hospital, Singapore. Among these 29 patients, eight (five male, three female) had intramuscular schwannomas.

RESULTS

The mean age of the eight patients was 40 (range 27-57) years. The most common presenting feature was a palpable mass. The mean interval between surgical treatment and the onset of clinical symptoms was 17.1 (range 4-72) months. Six of the eight tumours (75.0%) were located in the lower limb, while 2 (25.0%) were located in the upper limb. None of the patients had any preoperative neurological deficits. Tinel's sign was present in one patient. Magnetic resonance (MR) imaging showed that the findings of split-fat sign, low signal margin and fascicular sign were present in all patients. The entry and exit sign was observed in 4 (50.0%) patients, a hyperintense rim was observed in 7 (87.5%) patients and the target sign was observed in 5 (62.5%) patients. All patients underwent microsurgical excision of the tumour and none developed any postoperative neurological deficits.

CONCLUSION

Intramuscular schwannomas demonstrate the findings of split-fat sign, low signal margin and fascicular sign on MR imaging. These findings are useful for the radiological diagnosis of intramuscular schwannoma.

Erector Spinal Muscular Schwannoma of the Dorsal Ramus Nerve: A Case Report

We present a rare case of intramuscular schwannoma originating from the dorsal ramus nerve in a 62-year-old woman. The mass grew slowly, with pain developing upon touch five years prior. No neurological deficit was detected. The mass was observed in the erector spinae muscles in magnetic resonance imaging (MRI), and surgical excision was performed. The mass was well encapsulated with clear margin. The lesion appeared to originate from the cranial side. We completely removed the mass including the origin. Histopathology confirmed a schwannoma diagnosis. This is the first report, to our knowledge, of a dorsal ramus-nerve schwannoma within the erector spinae muscles.