Intraneural Ganglion Cyst of the Sciatic Nerve Treated Using Arthroscopic Hip Surgery: A Case Report

Femoral intraneural ganglion cyst: the first confirmed case report

BACKGROUND

Ganglion cysts affecting nerve are rare causes of neuropathy. The formation of intraneural ganglion cysts, once controversial, has recently been clarified. We describe the first modern description of a femoral intraneural ganglion cyst at the hip region.

METHODS

A patient presented with a 1 year history of radiating pain, quadriceps weakness and anteromedial leg numbness was found to have a femoral intraneural cyst with a hip joint connection on MRI.

RESULTS

Surgical disconnection of the articular branch led to improvement of the neuropathy and resolution of the cyst on postoperative MRI.

CONCLUSIONS

The unifying articular (synovial) theory describes the joint origin of intraneural cysts, even when they occur in unusual locations, and their propagation into the parent nerve. Knowledge of this theory can improve outcomes; surgery needs to address the joint origin or capsulolabral defect lest recurrence ensue.

Intraneural ganglion cysts originating from the hip joint: A single-center experience

INTRODUCTION/AIMS

Intraneural ganglion cysts (INGCs) are non-neoplastic mucinous cysts within the epineurium of peripheral nerves. Characteristics of INGCs around the hip joint have not been adequately described. We aimed to describe clinical features, imaging findings, and treatment outcomes in patients with INGCs originating from the hip joint.

METHODS

We retrospectively included cystic lesions around the hip joint satisfying the following inclusion criteria over 6 years: (1) multilocular elongated hyperintense cystic mass on T2-weighted imaging; and (2) distribution along the course of the peripheral nerve and its branches on magnetic resonance imaging (MRI).

RESULTS

Six patients with an INGC around the hip joint were identified. Parent peripheral nerves were the sciatic nerve (four patients), the superior gluteal nerve (one patient), and the nerve to quadratus femoris (one patient). Buttock, groin, or lower extremity pain/paresthesias were the initial symptoms in all patients. INGCs within the articular branches of the hip joint were identified on MRI. Four patients underwent arthroscopic debridement and capsulotomy. All patients showed generally favorable outcome regardless of treatment.

DISCUSSION

Physicians should consider the possibility of INGCs originating from the hip joint as a cause of nontraumatic hip, buttock, or lower extremity pain. This can occur in any nerve innervating the hip joint, and usually it originates in the posterior capsule of the hip joint. Arthroscopic surgery shows promising results; however, more information about the surgical technique and long-term follow-up results are needed.

Intraneural ganglion cyst of the lumbosacral plexus mimicking L5 radiculopathy: A case report

BACKGROUND

Intraneural ganglion cysts are benign gelatinous masses that form within the epineurium of a peripheral nerve. Only few cases of intraneural ganglion cyst arising from the hip joint have been reported.

CASE SUMMARY

A previously healthy 65-year-old woman who had been experiencing left buttock pain radiating to the dorsum of the foot for 2 years visited our clinic. Prior to visiting the clinic, she underwent lumbar spine magnetic resonance imaging and received physiotherapy, pain killers, and epidural injections based on a presumptive diagnosis of spinal stenosis for 2 years in other hospitals. Repeat magnetic resonance imaging revealed joint connection of the articular branch of the hip joint and rostral extension of the cyst along the L5 spinal nerve near the L5-S1 neural foramen. The patient was diagnosed with intraneural ganglion cyst arising from the articular branch of the hip joint based on high-resolution magnetic resonance neurography. Using the arthroscopic approach, a cystic opening within the intra-articular space was detected, and cyst decompression was then performed. The pain in the left leg was significantly relieved during the 6-mo follow-up.

CONCLUSION

Although intraneural ganglion cysts arising from the hip joint are rare, they can cause typical radicular pain and mimic common L5 radiculopathy. Typical cyst ascent phenomenon starting from the termination of the articular branch on magnetic resonance imaging is a crucial finding indicative of intraneural ganglion cysts arising from the hip joint.

Obturator Intraneural Ganglion Cysts: Joint Connected and Underdiagnosed

BACKGROUND

Intraneural ganglion cysts of the obturator nerve are rare. Our aim is to review cases of obturator intraneural ganglion cysts at our institution and those reported in the literature.

METHODS

We reviewed all cases evaluated by the senior author. A literature search was performed using the PubMed database and Google Scholar with the following terms: "obturator cyst," "obturator intraneural ganglion cyst," and "obturator intraneural ganglia." All cases underwent a retrospective review. Patient demographic data, including age, sex, and presenting signs and symptoms were recorded. Imaging studies were re-evaluated by 2 musculoskeletal radiologists experienced in the diagnosis of intraneural ganglion cysts.

RESULTS

We identified 2 cases of obturator intraneural ganglia at our institution; both were connected to the hip joint. We found 4 cases that were clearly diagnosed as intraneural ganglia in the literature, of which only 1 was recognized by the original authors as being joint connected, but based on our reinterpretation, 3 of 4 were joint connected. An additional 9 cases identified in the literature did not definitely report the nerve-cyst relationship, but based on our reinterpretation, were believed to be intraneural; 8 were joint connected.

CONCLUSIONS

We believe that obturator intraneural ganglion cysts adhere to the principles of the unifying articular theory. They arise from the anteromedial hip joint and extend into an articular branch and can reach the parent obturator nerve. Surgery should address the hip disease and/or the articular branch connection. Not appreciating the pathoanatomy of these cysts can lead to persistent or recurrent cysts.