IgG4-related Pachymeningitis as a Cause of Spinal Epidural Compression: Can Intraoperative Frozen Sections Predict the Underlying Pathology?

At times, spinal lesions are part of systemic manifestations of autoimmune disease. Awareness regarding their clinicopathological spectrum, particularly the lesions which usually respond to steroids/immunotherapy, is essential to avoid unwanted surgical morbidity. We discuss a case of a young-man presenting with thoracic spinal epidural compressive lesion which was indeed a manifestation of IgG4-related hypertrophic pachymeningitis. The mass was firmly adherent to the dura and extended into left neural foramen/paravertebral space which precluded complete excision. Frozen sections suggested fibro-inflammatory stroma with large areas of fibrosis and lymphoplasmacytic infiltrate. After subtotal excision, the patient improved with medical therapy at 1-year follow-up. Although uncommon, the case highlights the need to consider spinal presentation of this rare entity, especially in the context of autoimmune disorders or even in isolation. In this regard, intraoperative frozen section can hint the underlying inflammatory/autoimmune pathology, guide further course of surgery as well as limit unwarranted operative morbidity.

Revisiting Surgery in the Current Era of Gamma Knife for Cavernous Sinus Lesions.

Background: The challenges associated with surgeries of cavernous sinus (CS) lesions have shifted the management trend towards upfront gamma knife radiosurgery (GKRS). Although GKRS is effective in arresting the progression of certain small residual/recurrent lesions, its efficacy in alleviating neurological deficits is less evident. Furthermore, GKRS without establishing the histopathological diagnosis, at times can be detrimental. Objective: We present our clinical experience to reemphasize the role of surgery for CS lesions in the current era of upfront GKRS. Materials and Methods: We reviewed our database of 32 patients with various CS lesions treated by surgery for progressive cranial nerve deficits. The follow-up data were analyzed for the extent of resection, and in particular for improvement in their symptoms. Results: The lesions were confirmed as hemangioma (CSH)-8, meningioma-8, trigeminal schwannoma-6, chordoma-3, residual pituitary with CS extension-3, fungal granuloma-3, and dysgerminoma-1. Symptoms improved in 23 (complete in 13) and remained at least static in six patients. Follow-up ranged from 4-36 months. Conclusions: The nature of pathology should determine the management modality in CS lesions. Excision of CS schwannomas and chordomas yields rapid clinical improvement and good long-term outcomes. Resection is preferred for large CSH and functioning pituitary tumors. Although the clinical improvement may be less dramatic, surgery debulks the meningiomas. Most importantly, surgery also establishes the histopathological diagnosis of CS lesions. Even with an easy alternative of upfront GKRS, resection has a definite role in the primary management of most CS pathologies.

A novel fixation technique using anterior C1 screw in a pediatric solitary cervical spinal juvenile xanthogranuloma.

PURPOSE: Juvenile xanthogranuloma (JXG) presenting as solitary vertebral body lesion is infrequently seen and usually limited to one or two levels. We report a case of an isolated JXG with extensive cervical spinal (bony and extradural) involvement in a 6-year-old child. There was a diagnostic dilemma as the radiologic and intraoperative picture resembled tuberculosis. The spinal reconstruction was also challenging due to involvement of multiple vertebral levels and necessitated an anterior C1 screw. METHODS: The lytic lesion was multicompartmental, involving the craniovertebral junction and the subaxial spine (till C6 vertebral body) and extending into the retropharyngeal space. Noticeably, an associated thoracic syringomyelia was also present. Near-total excision of the lesion and 360° spinal fixation was performed using fibular strut graft. The graft was cranially anchored to the C1 anterior arch, thereby sharing the load with the posterior occipito-cervical instrumentation in order to avoid a construct failure due to cantilever effect. RESULTS: At 12-month follow-up, the patient had good clinico-radiologic outcome with evidence of bony fusion and resolution of syrinx. CONCLUSION: The report highlights the diagnostic dilemma of JXG lesion on both the radiology and surgery and discusses the challenges in the management and the relevant literature. The described technique can be a viable option in pediatric tumors with extensive C2 vertebral body involvement. Occasionally, extradural compression can have associated syrinx formation and the primary treatment per se could tackle the underlying syringomyelia.

Modified unilateral approach for mid-third giant bifalcine meningiomas: resection using an oblique surgical trajectory and falx window.

BACKGROUND: Utilizing the shortest available trajectory is the norm for excision of meningiomas. However, such an approach for the mid-third/central falcine meningiomas risks the adjoining draining veins and eloquent cortex. A larger size and bilaterality of such tumors adds to the surgical challenge. Herein, we report the surgical nuances of a modified unilateral approach in patients operated for giant bilateral symmetrical mid-third falcine meningiomas. METHODS: Five such patients were operated. The clinico-radiologic data was studied at presentation and at the follow-up. The meningiomas were subclassified into those that were located in the anterior and posterior half of the central falx, and their surgical trajectory was chosen accordingly. The tumor was excised through an oblique anterior or a posterior trajectory instead of directly working over the major draining veins and eloquent brain. The falx was incised to create a surgical window and access the tumor on the contralateral side. RESULTS: Four patients had meningiomas in the anterior half and one in the posterior half of central falx. Simpson excision was grade II in four patients. One patient showed small residual tumor and underwent stereotactic radiosurgery. The overall mean follow-up of the patients was 9.2 months. All the patients had good clinical outcome. CONCLUSIONS: Giant bifalcine meningiomas can be safely resected through a unilateral approach. Falx opening serves as a window to remove the tumor from the contralateral side. An oblique trajectory rather than an end-on access to these tumors minimizes the risk of venous and cortical injury.

"Suspended Posterior Tubercle of Atlas" with Atlantoaxial Dislocation.

INTRODUCTION: Congenital anomaly of the C1 posterior arch is a well-known entity and is often associated with atlantoaxial dislocation. However, a well-formed C1 posterior tubercle with absence of the remaining posterior arch is rare. Such unusual anomalies pose a surgical challenge as trying to delineate the arch early in the course of surgery could be potentially dangerous. We discuss here a similar case of C1 posterior arch defect with atlantoaxial dislocation and its management. CASE REPORT: A 17-year-old female presented with progressive spastic quadriparesis and neck pain. Evaluation revealed atlantoaxial dislocation with the presence of a well-formed posterior C1 tubercle in the absence of the rest of the posterior arch. C1-C2 joints were opened, and lateral masses were fused in reduced position. Intraoperatively, a posterior C1 tubercle was found suspended from the lateral masses by fibrous bands. The surgical nuances have been discussed. CONCLUSION: Presence of posterior tubercle alone with aplasia of the posterior arch results from a persistent posterior ossification center with nonextension of lateral ossification centers. In the presence of the C1 posterior fibrous arch, the joint spaces must be exposed first before attempting to delineate the posterior arch. This will prevent inadvertent injury to the vertebral artery and dura.

Frozen Section Can "Sharpen" or "Sand Off" the Surgeon's Knife: 2 Case Illustrations with Skull Base Meningioma Mimics.

BACKGROUND: Lesions at the skull base warrant careful evaluation of imaging and meticulous preoperative planning. Unnecessary radical resection of these lesions could add to surgical morbidity. Occasionally, dural-based inflammatory or infectious lesions at this site radiologically mimic meningiomas, which are commonly encountered entities at this site. Not all lesions require excision, and it could be harmful in a few cases. CASE DESCRIPTION: Two patients had skull base lesions that resembled a meningioma on imaging, whereas frozen section in both cases differed from the preoperative diagnosis, showing an inflammatory lesion in the first case and invasive aspergillosis in the second case. Formalin-fixed, paraffin-embedded sections confirmed the frozen section diagnosis. Safe resection was performed in the first case, whereas surgery was abandoned and the patient was started on antifungal therapy in the second case. Both patients had a good outcome. CONCLUSIONS: This report underscores the usefulness of intraoperative frozen section to decide on a further course of treatment when faced with such unexpected situations. Frozen sections and crush smears hold great potential to avoid unwarranted surgical morbidity, particularly for skull base lesions.