Spinal ependymomas. Part 2: Ependymomas of the filum terminale

OBJECT Ependymomas of the filum terminale provide specific surgical challenges due to their often enormous size, contact with nerve roots of the cauda equina and conus, and potential for subarachnoid dissemination. This study presents treatment results for these tumors over a 30-year period. METHODS Among 1447 patients with tumors of the spinal canal treated between 1980 and 2014, 618 patients presented with extramedullary tumors. Of these, 42 patients (25 males, 17 females) demonstrated a myxopapillary ependymoma in the lumbosacral region. Thirty-four patients underwent 36 operations for 39 such tumors. The mean patient age was 38 ± 14 years (range 11−73 years), with an average clinical history of 37 ± 67 months. Patients were followed through outpatient visits and questionnaires, with a mean follow-up of 10 years (127 ± 100 months). Twenty-seven operations were performed to treat de novo tumors and the remainder were undertaken on recurrent tumors. Short-term results were determined for individual symptoms, and tumor recurrence rates were calculated with Kaplan-Meier statistical analyses. RESULTS Subarachnoid dissemination was observed in 11 patients and was related to previous surgery in 9 patients and associated with extensive tumors in 2 patients. Gross-total resections (GTR) were achieved in 28 operations (77.7%) and subtotal resections in the remainder. Subtotal resections were restricted to unencapsulated ependymomas (61.5%). Radiotherapy was employed after 6 operations on unencapsulated tumors, with 5 of these also demonstrating subarachnoid seeding. Permanent surgical morbidity affected 3 patients who experienced permanent worsening of bladder function, while 7 patients showed no postoperative changes, and the remaining 26 operations were followed by improvements. Long-term outcome depended on the amount of resection and the presence of a tumor capsule. Eight of 9 tumor recurrences affected unencapsulated tumors, of which 3 had undergone GTR. The overall recurrence rates were 6.6%, 19.0%, and 37.0% after 1, 10, and 20 years, respectively. For unencapsulated ependymomas, the corresponding rates were 15.6%, 32.5%, and 66.2% after 1, 10, and 20 years, respectively, with significantly lower rates of 9.1% after 10 and 20 years for encapsulated tumors. Postoperative radiotherapy tended to prolong the recurrence-free interval for patients with unencapsulated tumors. Five patient deaths occurred during follow-up, of which 2 deaths were tumor related and occurred at 216 and 287 months after surgery. CONCLUSION Extramedullary ependymomas are slow-growing tumors in the lumbosacral region, sometimes with an indolent course for long periods of time. Despite their delicate location and often enormous size, surgical morbidity in experienced hands is low, with good chances for postoperative clinical improvements and very low recurrence rates after GTR for encapsulated tumors. The role of postoperative radiotherapy remains controversial. Radiotherapy may be considered after incomplete resections of unencapsulated tumors and/or for patients with subarachnoid dissemination.

Subarachnoid dissemination of intraventricular tumors following simultaneous endoscopic biopsy and third ventriculostomy

Object Endoscopic biopsy with concomitant third ventriculostomy (ETV) is a well-established diagnostic and therapeutic maneuver in patients presenting with noncommunicating hydrocephalus resulting from a tumor of the pineal region or posterior third ventricle. Fenestration of the floor of the third ventricle theoretically provides a conduit for the subarachnoid dissemination of an intraventricular tumor. The aim of this study was to ascertain the rate of leptomeningeal dissemination following this surgical procedure. Methods The authors conducted a review of all patients for whom an ETV and simultaneous endoscopic biopsy procedure or tumor resection had been performed at their institutions between 1995 and 2008. Patients were divided into high or low risk groups by leptomeningeal metastatic potential based on pathology. All available postoperative clinical and radiographic data, including MR imaging of the brain and spinal cord, as well as CSF sampling were evaluated when available. A review of the literature was then conducted to establish rates of distant leptomeningeal dissemination for comparative purposes. Results Thirty-two patients satisfied the criteria for study inclusion. Pathology revealed that 22 had a high risk for leptomeningeal dissemination. New leptomeningeal disease (1 yolk sac tumor and 1 pineoblastoma) occurred in 2 patients. The median clinical and brain MR imaging follow-ups overall were 34 (range 2–103 months) and 38 months (range 1–94 months), respectively. Follow-up MR imaging of the spine was performed in 12 patients (median 7 months postoperation), and CSF was analyzed in 15 patients (median 1 month postoperation). A Kaplan-Meier survival analysis predicted a 2-year metastasis-free survival of 94.7% for high-risk patients. Baseline rates of dissemination when ETV was not performed were in general between 8 and 24% for various high-risk pathologies according to a literature review. Conclusions The rate of leptomeningeal metastasis of tumors in this biopsy and ETV study was not increased when compared with rates from large series in the literature.

Synchronous subarachnoid drop metastases from a pituitary adenoma with multiple recurrences

✓ The authors report the case of a 49-year-old man with synchronous drop metastases from a multiply recurrent somatotroph pituitary adenoma. The metastatic lesions were found in the subarachnoid space of the cauda equina and foramen magnum 18 years after the initial diagnosis of the disease. Five transsphenoidal resections had previously failed to cure the sellar tumor. Two of these, performed 4 and 5 years before the patient's current presentation, had been complicated by cerebrospinal fluid rhinorrhea that necessitated lumbar drainage. Resections of the two subarachnoid lesions, separated by 14 months, removed pathologically aggressive pituitary adenomas. There were no signs of local recurrence or subarachnoid dissemination of disease during the postoperative follow-up periods, which lasted 18 and 4 months, respectively. Previous cases of subarachnoid spread of a pituitary adenoma have been associated with multiple intracranial metastases, multiple intraspinal metastases, or widely disseminated disease. This case demonstrates that subarachnoid metastasis of a pituitary adenoma, particularly when it follows multiple operations, is not invariably widely disseminated or associated with a very poor prognosis.

Subarachnoid Fat Dissemination after Resection of a Cerebellopontine Angle Dysontogenic Cyst: Case Report and Review of the Literature

ABSTRACT OBJECTIVE AND IMPORTANCE This case report illustrates the clinical and radiological relevance of extensive intracranial subarachnoid and ventricular dissemination in dysontogenic (dermoid) tumors. CLINICAL PRESENTATION We describe a patient with a cerebellopontine angle dysontogenic tumor. Postoperatively, the cyst disseminated fat particles extensively into the subarachnoid space. Magnetic resonance imaging (MRI) studies revealed continuous dispersion of the fat particles into the cerebral cisterns, subarachnoid space, and ventricles. INTERVENTION Eight years of clinical and MRI follow-up demonstrated neither neurological deterioration in the patient nor growth of the multiple lesions. CONCLUSION Intracranial subarachnoid dissemination of fat material may occur during the preoperative or postoperative course of dermoid and epidermoid cysts. Aseptic meningitis or other complications such as hydrocephalus, seizures, or cranial nerve deficits also may occur owing to spillage of intracranial cyst contents into the subarachnoid space. MRI can detect the presence of fat drops that may adhere to the surrounding structures or migrate with the cerebrospinal fluid flow. Intracranial disseminated fat particles can remain silent without radiological or neurological change, justifying a wait-and-see approach. During long-term postoperative follow-up, however, regular MRI studies and clinical examinations are necessary to avoid potential complications.