Temporal extradural ectopic craniopharyngioma

Ectopic craniopharyngioma of the orbit: illustrative case

BACKGROUND

Craniopharyngiomas are uncommon malformations of the sellar or parasellar region that are partly cystic and calcified and have low histological grade. The typical age of presentation is bimodal, with peak incidence rates in children at age 5 to 14 years and in adults at age 50 to 74 years. The usual clinical manifestations are related to endocrine deficiencies due to mass effect along with visual impairment and increased intracranial pressure. If a tumor is favorably localized, the treatment of choice is complete resection.

OBSERVATIONS

The authors presented a unique case of a 61-year-old man with a suspicious cystic lesion in the right orbital roof that was causing right-sided headaches with pressure and pain in the right eye. Both computed tomography and magnetic resonance imaging were used for further evaluation and showed a suspicious lytic bone lesion that had an epicenter within the orbital rim, which was highly suggestive of a tumor of interosseous origin. After removal, the tumor was identified by pathology as a craniopharyngioma.

LESSONS

The importance of this case report is in documenting a unique case of an ectopic craniopharyngioma in the orbit, adding to current hypotheses of the pathogenesis of ectopic craniopharyngiomas, and presenting an extensive review of literature.

Unusual and Rare Locations for Craniopharyngiomas: Clinical Significance and Review of the Literature

OBJECTIVE

This study discusses rare and unusual locations of primary craniopharyngiomas.

METHODS

We describe a case of a craniopharyngioma in the cerebellopontine angle. As a result of this unusual location, we performed a literature review of the ectopic occurrence of craniopharyngiomas using Pubmed, Cochrane Database, Trip, and Google Scholar to search for the terms "unusual," "uncommon," and "ectopic" in combination with "craniopharyngioma." The bibliographies of relevant articles were also searched.

RESULTS

We found 28 reported cases of rare anatomic locations for primary craniopharyngiomas. The average age of the patients was 30.8 years. Several patients had Gardner syndrome.

CONCLUSIONS

Craniopharyngiomas are most often located in the suprasellar region. Presentation in sites outside the parasellar region is rare. Among these ectopic sites, the cerebellopontine angle appears to be the most common location.

Primary ectopic frontotemporal extradural craniopharyngioma

We present a case of primary ectopic frontotemporal extradural craniopharyngioma. Primary ectopic craniopharyngiomas are very rare and have been reported involving the fourth ventricle, infrasellar region, lateral ventricle, temporal area, cerebellopontine angle, clivus, corpus callosum, and prepontine cistern. There was just 1 case of craniopharyngioma previously presented in the literature, with nearly same location as the presenting case.

Ectopic craniopharyngioma of the fourth ventricle in a patient with Gardner syndrome

Ectopic craniopharyngioma is uncommon and a craniopharyngioma confined purely within the fourth ventricle is extremely rare. We report a craniopharyngioma of the fourth ventricle in a 20-year-old man with Gardner syndrome. Imaging characteristics of craniopharyngiomas and fourth ventricle lesions are discussed with a review of the literature regarding the pathogenesis of craniopharyngiomas and the possible association with Gardner syndrome.

Isolated petrous apex ectopic craniopharyngioma

Primary ectopic craniopharyngioma is a rare entity. Isolated petrous apex bone location has not been reported previously. This study reports a case of 26-year-old male with right abducent nerve palsy. CT and MRI imaging reveal right petrous apex cystic lesion. No sellar or suprasellar region involvement was found. Endoscopic endonasal transphenoid approach has been successfully performed. Histopathology examination confirms the diagnosis of adamantinomatous craniopharyngioma. So far, it’s probably the first case report of primary ectopic craniopharyngioma isolated in the petrous apex. This case report supports the premise that primary ectopic craniopharyngioma is a multifactorial process that starts with an error from migrated embryological cells.

Modern instrumentation of the pediatric occiput and upper cervical spine: review article

BACKGROUND

Rigid screw rod techniques for cervical stabilization are widely used in adults. The benefits of rigid internal fixation include increased fusion rates, improvements in deformity correction, and diminished immobilization requirements. Applications of these techniques in children are challenging due to size constraints and the pathologic conditions encountered which require instrumented cervical fusions. Preparation as well as thorough understanding of the anatomy and surgical techniques is paramount to surgical safety in pediatric patients.

QUESTIONS/PURPOSES

This review article serves as an educational tool regarding the use of modern posterior instrumentation techniques for pediatric cervical deformity.

METHODS

Expert review based on clinical expertise and literature review.

RESULTS

The use of rigid screw rod instrumentation for the pediatric occiput and upper cervical spine is discussed. Preoperative imaging requirements for pediatric patients undergoing cervical spine surgery are reviewed. Anatomy, morphologic studies, and surgical techniques are discussed for each area of instrumentation.

CONCLUSIONS

Modern posterior cervical instrumentation techniques can be safely applied to the majority of pediatric patients who require an instrumented posterior cervical fusion. Patient safety revolves around thorough preoperative imaging tests, understanding of upper cervical anatomy, and meticulous surgical technique. Modern instrumentation leads to an improvement in fusion rates and a diminishment in immobilization requirements.

Rigid variety occiput/C1-C2-C3 internal fixation in pediatric population

PURPOSE

The purpose of this study was to review our experience of rigid internal fixation of craniovertebral junction in pediatric population. A new technique of reduction of basilar invagination with atlantoaxial dislocation is described. To the best of our knowledge and available scientific literature, this technique has not yet been described in younger patients.

METHODS

We have managed 27 children by rigid variety of occiput/C1-C2-C3 internal fixation of various craniovertebral junction pathologies. All patients were subjected to thin cuts of computed tomography with 3D reconstruction for selecting appropriate rigid construct. Eight children had occiput-C2, 3 had occiput-C2-C3, and 16 had C1-C2 hardware constuct. One patient of C1-C2-plate fixation had section of C2 nerve root ganglia. Basilar invagination with atlantoaxial dislocation was reduced by new distraction/compression techniques.

RESULTS

Improvement in clinical features and correction of deformity with solid hardware construct were seen in all patients. Follow-up period ranged from 5-72 months. One patient was lost to follow-up, and one case died of compression of vertebral artery at C1 lateral mass. Patients of myelopathy had recovery rate of 90.9%. Hardware failure was seen in one patient, and wound infection was observed in two cases.

CONCLUSIONS

Rigid variety of occiput/C1-C2 internal fixation is a safe and effective method in the management of variety of craniovertebral pathologies in pediatric population. This new technique of reduction of basilar invagination with atlantoaxilal dislocation from posterior approach may alleviate the need of high morbity associated with surgical procedure like transoral odontoidectomy in younger patients.

Severe spinal cord injury in craniocervical dislocation. Case-based update

BACKGROUND

Craniocervical distraction injuries, including atlanto-axial dislocation (AAD) and atlanto-ocipital dislocation (AOD), are often associated with severe spinal cord involvement with high morbidity and mortality rates. Many patients with these injuries die at the accident scene, but advances in emergency resuscitation and transport permit that many patients arrive alive to hospitals.

DISCUSSION

Children with craniocervical distraction injuries usually present with a severe cranioencephalic traumatism that is the most relevant lesion at admission. After resuscitation and hemodynamic stabilization, the spinal cord damage appears as the main lesion. Apnea and quadriparesis, or quadriplegia, are usually present at the onset. Early diagnosis and management perhaps decrease life-threatening manifestations of the spinal lesion. But even so, the primary spinal cord insult is often irreversible and precludes obtaining a satisfactory functional outcome.

PATIENTS AND METHODS

We report the findings of four children with craniocervical distraction injuries (AOD and AAD) who presented with severe spinal cord damage. All patients were admitted with respiratory distress or apnea together with significant brain injuries. The medical records pertaining to these patients are summarized in regard to clinical features, management, and outcome.

CONCLUSIONS

In spite of timely and aggressive management, craniocervical injuries with spinal cord involvement continue to have a dismal prognosis. Outcome is closely related to the severity of the initial brain and spinal cord damage and is nearly always fatal in cases of complete spinal cord transection. Priority should be given to life-threatening complications. Ethic issues on indications for surgery deserve a detailed discussion with the children's parents.

Ectopic recurrent craniopharyngioma of the frontal bone

Ectopic recurrence of craniopharyngioma is a rare phenomenon after transcranial resection of the primary tumor. The authors present a case of ectopic recurrent adamantinomatous craniopharyngioma of the frontal bone resected 16 years after initial transcranial resection of the primary tumor. The lesion was first radiographically described 12 years after surgery and was adjacent to the osteosynthesis plate that had been implanted at the craniotomy site. The recurrent craniopharyngioma was totally resected via a lateral eyebrow approach. No infiltration of the meninges or the brain was detected. Only 50 cases of ectopic recurrent craniopharyngioma have been described to date, with the present case being the first one with recurrence located at the skull bone. So far 2 mechanisms have been described: contamination with tumor cells alongside the surgical tract and spreading via CSF and the subarachnoid space. The authors reviewed the literature, provided the largest collection of cases so far, and performed basic statistical analysis regarding ectopic recurrence. Pediatric and adult patients as well as male and female ones are affected equally by this phenomenon. The mean time of ectopic recurrence after initial surgery was 7.1 years. Ectopic recurrence, although rare, should always be considered in a patient with a newly diagnosed intracranial lesion who has undergone transcranial craniopharyngioma resection before.

Isolated primary craniopharyngioma in the cerebellopontine angle

Between January 2000 and January 2011, we diagnosed three patients with isolated craniopharyngioma in the cerebellopontine angle (CPA). Brain MRI revealed cystic lesions with various imaging characteristics, including hypointensity on T1-weighted (T1W) images and hyperintensity on T2-weighted (T2W) images. The first patient's lesion showed rim enhancement after gadolinium administration. The second patient's lesion showed mixed signal intensity on both T1W and T2W images. The third patient's MRI showed a well-defined cystic lesion in the right CPA that compressed the brainstem. This lesion was hyperintense on T1W images and hypointense relative to cerebrospinal fluid on T2W images, and was peripherally enhanced after gadolinium administration. All three patients underwent surgical intervention through a suboccipital retrosigmoid craniotomy/craniectomy and lesions that did not adhere to adjacent tissues were removed completely. Histopathological examination confirmed the tumors to be adamantinomatous craniopharyngioma. The post-operative course was uneventful for all patients uneventful and no tumor recurrences were detected at the last follow-up. Primary CPA craniopharyngioma can be completely removed surgically, provided it does not densely adhere to vital structures.

Complications and outcomes of posterior fusion in children with atlantoaxial instability

INTRODUCTION

Atlantoaxial instability (AAI) is an uncommon disease in children. Surgical treatment of pediatric patients with AAI poses a challenge to spine surgeons because of the patients' immature bone quality, extensive anatomical variability, and smaller osseous structures. In this study, the authors report complications and outcomes after posterior fusion in children with AAI.

METHODS

The authors reviewed medical records of patients 13 years old and younger with AAI who underwent posterior fusion in the Nagoya Spine Group hospitals, a multicenter cooperative study group, from January 1995 to December 2007. We identified 11 patients who underwent posterior fusion, and analyzed their clinical outcomes and complications. To determine if vertical growth within the construct continued after posterior fusion, in three patients at 5 or more years following occipito-cervical (O-C) fusion, intervertebral disc heights and vertebral heights between the fused and non-fused levels were compared on the final follow-up.

RESULTS

The initial surgeries were C1-C2 fusions in six patients and O-C fusion in five patients. Successful fusion ultimately occurred in all patients, however, the complication rate related to the operations was high (64%). Complications included neurologic deterioration, pedicle fracture with pedicle screw insertion, C1 posterior arch fracture with lateral mass screw insertion, perforation of the skull with a head pin placement, and fusion extension to adjacent vertebrae. Two patients required reoperation. The mean fixed and non-fixed intervertebral disc heights on the final follow-up were 2.6 and 5.3 mm, respectively, showing that the disc height of the fixed level was less than the non-fused level. Each vertebra lengthened similarly between fused and non-fused levels except for C2 which had a lower growth rate than the other vertebrae.

CONCLUSIONS

A high complication rate should be anticipated after posterior fusion in children with AAI. Careful consideration should be paid to pediatric patients with AAI treated by screw and/or rod systems. After posterior fusion in pediatric patients, each vertebra continued to grow, in contrast the disc height decreased between fused levels.

Anatomical feasibility of pediatric cervical pedicle screw insertion by computed tomographic morphometric evaluation of 376 pediatric cervical pedicles

STUDY DESIGN

Prospective analysis of computed tomographic images of 376 normal pediatric cervical pedicles.

OBJECTIVE

To study the normal cervical pedicle morphometrics, the changes in pedicle morphology with skeletal growth, and the possibility of pedicle screw insertion.

SUMMARY OF BACKGROUND DATA

Although the usage of cervical pedicle screws in adults has become established, the feasibility of its application in children has not been studied. There are no in vivo studies that define the normal pediatric cervical pedicle morphometrics and its changes with growth and development of the child.

METHODS

A total of 376 normal pediatric cervical spine pedicles of 30 children (mean age = 6.7 ± 3.9 years) were analyzed for pedicle width (PW), pedicle height (PH), pedicle length (PL), pedicle axis length (PAL), transverse pedicle angle (TPA), and sagittal pedicle angle (SPA). The study population was categorized into three age groups (A: <5 years, B: 5-10 years, and C >10 years). The mean values of these parameters in the different age groups and the possibility of application cervical pedicle screws were studied. RESULTS.: The mean PW was lowest in the C3 vertebra and increased distally to be widest at C7. Sixty percent of C3 pedicles had a width less than 4 mm making screw passage risky and unsafe. With growth, the PW increased at all levels but this increase was significant only up to the age of 10 years. More than 75% of adult pedicle dimensions were achieved by 5 years of age. The mean PL at all levels remained the same with no significant increase with growth. However, the PAL showed continuous increase with growth similar to PW. The PAL also showed an increase from C3 to C7. The PH was always more than the PW at any level. Mild insignificant asymmetry was present between the right and left side pedicles in all values.

CONCLUSION

With growth, there was a gradual increase in PW, PH, and PAL but was mainly before the age of 10 years. Majority of C3 pedicles were thin making screw fixation unsafe. However, at all other levels, the pedicle morphometrics per se were adequate and do not restrict safe application of 3-mm cervical pedicle screw.

Pituitary stalk craniopharyngioma

Craniopharyngiomas are benign but aggressive neoplasms arising along the craniopharyngeal duct. It is frequently located in the suprasellar region. Primarily pituitary stalk craniopharyngioma is unusual and uncommonly early diagnosed, before it enlarges and extends to supra or parasselar region. This unusual location and the small size pose therapeutic dilemmas, since it has the ability to grow larger. Currently, no consensus exists regarding the optimal management. The authors have recommended complete resection.

Radiographic evaluation of the technique for C1 lateral mass and C2 pedicle screw fixation in three hundred nineteen cases

STUDY DESIGN

Retrospective radiographic study of the technique for C1 lateral mass screw (C1LMS) and C2 pedicle screw (C2PS) fixation.

OBJECTIVE

To evaluate (1) the accuracy of the C1LMS and C2PS placement; (2) the fusion rate between C1 and C2; (3) the risk for vertebral artery (VA) injury.

SUMMARY OF BACKGROUND DATA

C1LMS and C2PS fixation is widely used when treating atlantoaxial instability. Several authors have reported their experience focusing on the technical outcomes, with many reporting fusion rates near 100%. However, most of them are relatively small series, and many have applied only plain postoperative radiographs instead of computed tomography (CT). Thus, we feel that the accuracy of C1LMS and C2PS placement has not been fully analyzed, as well as the anatomic relationship between the VA and the screws.

METHODS

Between December 2000 and September 2008, the fusion status and accuracy of the screws were evaluated on the postoperative reconstructive CT of 319 patients with atlantoaxial instability. Cases with malpositioned screws underwent CT angiography or magnetic resonance angiography after surgery, to evaluate potential VA injury.

RESULTS

C1LMS of 95.5% and C2PS of 92.8% were found to be in a "good" position. After 2007, six cases had malpositioned screws, which were all in the "out" or "down" area of the C2 pedicle. Five cases underwent CT angiography and 1 had magnetic resonance angiography to evaluate potential VA injury. No occlusion, associated aneurysm or fistula of the VA was found. All cases (100%) achieved solid fusion between C1 and C2.

CONCLUSION

C1LMS of 95.5% and C2PS of 92.8% were confirmed to be in good position. None of the screws including the malpositioned caused VA injury, clinically or radiographically. The technique for C1LMS and C2PS fixation appears to be safe and effective.

Metastatic craniopharyngioma: case report and literature review

BACKGROUND

Distant spread of craniopharyngioma is a rare but important complication. Most cases are a result of spread along the surgical path. We describe a rare case of metastatic leptomeningeal craniopharyngioma as a result of dissemination along CSF pathways in a child. A review of previously described cases is provided.

CASE PRESENTATION

A 14-year-old male was diagnosed with metastatic craniopharyngioma on routine follow-up imaging after multiple surgeries and radiation for locally recurrent craniopharyngioma. The lesion was erosive through the right parietal bone, but had remained clinically silent. The lesion was distant from previous surgical paths. The patient underwent right parietal craniotomy and resection of the lesion. Duraplasty and cranioplasty were necessary for closure. Histopathology confirmed adamantinomatous craniopharyngioma. One-year follow-up demonstrated no recurrence.

DISCUSSION

A review of reported cases suggests that leptomeningeal implantation may be an important step in metastases of craniopharyngioma, although the mechanism is poorly understood. Attention to tumor spillage at the time of surgery may be important in preventing distant recurrences.

Treatment of pediatric atlantoaxial instability with traditional and modified Goel-Harms fusion constructs

There are several treatment options for rigid fixation at C1-C2 including Brooks and Gallie type wired fusions and C1-2 transarticular screws. The use of a Goel-Harms type fusion, a construct with C1 lateral mass screws and C2 pedicle screws, has not been extensively described in pediatric patients. Here, we describe its relatively safe and effective use for treating pediatric patients by retrospective chart review of patients treated by the senior author for atlantoaxial instability with a Goel-Harms-type constructs during a 3-year period (2005-2007). Six patients were treated using Goel-Harms-type constructs. Five patients were treated utilizing a construct containing C1 lateral mass screws and C2 pedicle screws; one patient was treated using construct containing C1 lateral mass screws and C2 trans-laminar screws. The patients ranged in age from 7 to 17 years old (mean 12.7). All patients had findings of an os odontoideum on CT scans and three of the six patients had T2 hyperintensity on MRI. Three of the six patients presented with transient neurologic deficits: quadraplegia in two patients and paresthesias in two patients. In each patient C1 lateral mass and C2 screws were placed and the subluxation was reduced to attain an anatomical alignment. No bone grafts were harvested from the iliac crest or rib. Local morsalized bone and sub-occipital skull graft was used. All patients tolerated the procedure well and were discharged home on post-operative day 3-4. The patients wore a hard cervical collar and no halo-vests were needed. All patients had solid fusion constructs and normal alignment on post-operative imaging studies performed on average 14 months post-operatively (range: 7-29). The results demonstrated that Goel-Harms fusions are a relatively safe and effective method of treating pediatric patients with atlantoaxial instability and are not dependent on vertebral anatomy or an intact ring of C1. Follow-up visits and studies in this limited series of patients demonstrated solid fusion constructs and anatomical alignment in all patients treated.