Interhemispheric transcallosal transforaminal approach and its variants to colloid cyst of third ventricle: Technical issues based on a single institutional experience of 297 cases.

CONTEXT: Colloid cysts are benign intracranial lesions that usually involve the anterior third ventricle with varying appearance on imaging studies. The number of articles debating the origin of this tumor is surpassed by papers proposing the best modality available for its treatment. AIM: The purpose of this study is to analyze the clinical presentation and surgical outcome of colloid cysts surgically managed over a period of thirty-two years and evaluate the technical issues based on our experience. STUDY DESIGN: This is a retrospective case series study. MATERIALS AND METHODS: This is a retrospective case series study on 297 consecutive patients with colloid cysts who were operated. The case records of all the patients were evaluated to record the clinical symptoms and signs, imaging findings, surgical procedure, complications and follow-up data. RESULTS: There were 178 (60%) males and 119 (40%) females, their age ranging from 9 to 66 years with a mean age of 28 years. The mean duration of symptoms was 1.8 months. Raised intracranial pressure headache was the most common initial presenting symptom followed by visual blurring, memory disturbance and drop attacks with gait unsteadiness. The tumor was an incidental imaging finding in five patients (2%). While an interhemispheric transcallosal approach was used in 275 (92.6%) patients, it was trans-cortical in 22 (7.4%). Twenty-two patients required emergency surgery in view of worsening sensorium. Postoperative complications included memory impairment, limb weakness and seizures. Despite documented complete excision of the tumor in 6 cases, 8 patients had recurrence of tumor during follow-up. CONCLUSION: Colloid cysts are potential life threatening but benign lesions that can be removed safely with low morbidity and mortality through the interhemispheric transcallosal approach and its variants. The possibility for recurrence warrants, close imaging follow-up after surgery. It is essential for neurosurgeons to be familiar with the different transcallosal approaches to reach the third ventricle especially for a posteriorly situated cyst and a narrow foramen of Munro.

Brainstem ganglioglioma in an infant: Case report and review of literature.

Gangliogliomas are well differentiated, usually low grade, neuroepithelial tumors that comprise of neoplastic ganglion cells in combination with neoplastic glial cells. Occasionally, glial cells may show anaplastic features and are then labeled as anaplastic gangliogliomas. Most of the reported gangliogliomas are supratentorial tumors, predominantly in the temporal lobe. Brainstem location has been reported infrequently. As with cortically based gangliogliomas, though the primary treatment is resection, this is often not possible due to the eloquence of surrounding involved parenchyma. Here, we report a case of brainstem tumor in an 8-month-old child that was substantially resected and was histopathologically Grade 1 ganglioglioma. As per review of English literature, there has been no case of brainstem ganglioglioma reported in an infant (less than 1 year age). We discuss the surgical difficulties in the radical excision of such benign tumors and review literature on pediatric brainstem gangliogliomas.

A retrospective study of primary cerebellar glioblastoma multiforme in adults.

Primary cerebellar glioblastoma multiforme (GBM) is a rare tumour in adults that accounts for less than 1% of all patients with GBM. In view of their rarity, the pathogenesis and prognosis of cerebellar GBM are not yet completely understood. The aim of this study was to retrospectively analyse patients with primary cerebellar GBM treated in our institute over a period of 10 years. Data from the case records of five adult patients with cerebellar GBM was evaluated and their outcome was assessed. We observed local failure in patients who reported back with recurrence. The presence of brainstem infiltration was a significant factor influencing progression-free survival. The overall prognosis was worse than for patients with supratentorial GBM. In view of their rarity, a meta-analysis is required to assess the pathogenesis and prognostic factors affecting overall survival in patients with cerebellar GBM.

Factors predicting the need for cerebrospinal fluid diversion following posterior fossa tumor surgery in children.

BACKGROUND: No consensus exists regarding the management of hydrocephalus in children with posterior fossa tumors before, during or after surgery. In the present study we analyze the factors that predispose to persistent hydrocephalus and the need for a postoperative cerebrospinal fluid (CSF) diversion procedure. METHODS: Pediatric patients who underwent surgery for posterior fossa tumors with hydrocephalus at our hospital were reviewed to evaluate the need for a postoperative CSF diversion procedure. Patients having undergone CSF diversion preoperatively were excluded from the study group. The case records of 84 patients were reviewed. The factors evaluated included age at diagnosis, duration of symptoms, severity of preoperative hydrocephalus, tumor size, tumor location, tumor histology, extent of tumor resection and postoperative complications that could be related to CSF circulation disorders. RESULTS: At the time of presentation, 80/84 (95.2%) patients had symptomatic hydrocephalus; 25/84 (29.8%) patients required a CSF diversion procedure in the postoperative period. Children presenting with symptom duration of less than 3 months had a significantly higher requirement for postoperative CSF diversion in comparison to those with longer symptomatology (p = 0.016). Evan's index and frontal and occipital horn ratio on preoperative imaging were found to correlate closely with the need for postoperative shunt (p = 0.001 and p < 0.001, respectively). The requirement for shunt was statistically higher in patients with midline tumors in comparison to laterally placed lesions (p = 0.04) and in children with medulloblastoma (p < 0.001) and ependymoma (p = 0.016) as the tumor subtypes. Children who underwent intraoperative external ventricular drainage (EVD) had a shunt insertion rate of 39.6% compared with 16.7% of those who did not have an EVD (p < 0.001). Patients with meningitis and pseudomeningocele in the postoperative period had a statistically significant higher risk of shunt requirement (p = 0.008 and p = 0.016, respectively). The mean age at diagnosis and the extent of tumor resection did not correlate with the need for CSF diversion. CONCLUSION: The fact that less than one-third of patients require a CSF diversion after posterior fossa tumor resection refutes the role of prophylactic endoscopic third ventriculostomy. Awareness regarding the factors that can predict persistent postoperative hydrocephalus is essential for the surgeon during patient counseling and surgical planning, and also in deciding the intensity of postoperative clinical and radiological monitoring.

Primary Ewing's sarcoma of the spine presenting as acute paraplegia.

Ewing's sarcoma is a primary bone malignancy with the highest incidence in the second decade of life. Although it mostly affects the metaphyseal region of long growing bones, involvement of spine is not very uncommon especially the sacrum. Nonsacral spinal Ewing's sarcoma is rarer and often mimics a benign condition before spreading extensively. They present with neurologic deficits due to spinal cord compression, but acute onset paraplegia has not been previously reported. A high index of clinical suspicion can clinch the diagnosis early in the course of the disease. A prompt intervention is required to keep neurological damage to a minimum, and a correct combination of surgery, chemotherapy, and radiotherapy is required for better long-term patient outcome. We report a 16-year-old female who presented with acute paraplegia and had an excellent postoperative outcome after radical excision of a D9 Ewing's sarcoma.

Epidermoid cyst of the brainstem in children: case-based update.

Epidermoid cysts are rare, slow growing, space-occupying lesions of early adulthood. Among the various locations, involvement of the brainstem is quite exceptional. In children, these tumors are extremely uncommon; only 4 purely intrinsic brainstem epidermoids are reported in the literature. The pathogenesis of true intraaxial brainstem epidermoid is unclear and is usually not considered in the preoperative differential diagnosis of brainstem tumors. We report 2 additional cases of brainstem epidermoid cysts occurring in children, underlining their clinical characteristics, the difficulties faced in the diagnostic work-up, and the surgical treatment adopted. These tumors pose a surgical challenge and attempts at aggressive removal of the cyst wall are fraught with increased risks of morbidity and mortality. On the other hand, cases treated more conservatively show good or excellent results with minimal complications. Neurosurgical judgment at the time of surgery is warranted to ensure maximum resection while minimizing postoperative neurologic deficits.

A single institution series of cavernomas of the brainstem.

We retrospectively analyzed a series of patients with brainstem cavernomas of the medulla, pons, or midbrain to attempt to define the natural history, indications for surgery, and outcome after surgical resection. Between 1993 and 2008, 52 patients with cavernomas of the brainstem presented to our institute and were managed either surgically or conservatively. Twenty-three patients underwent surgical excision using standard skull base approaches. Outcomes were correlated to the number of preoperative hemorrhages, location of the cavernoma, timing of surgery in relation to the hemorrhage and the preoperative neurological status. Nine patients improved after surgery, 12 deteriorated and two died. In the conservatively managed group, 15 patients had a good outcome, 11 deteriorated and one died. Multiple hemorrhages, poor preoperative neurological status and surgery during the acute phase were predictive of the surgical outcome. Excision of brainstem cavernomas should be considered in patients with symptomatic hemorrhages whose lesions approach the pial surface. Patients with minimal stable neurologic deficits without recurrent bleeds should be managed conservatively.

Iophendylate myelography induced thoracic arachnoiditis, arachnoid cyst and syrinx, four decades later.

Iophendylate (Myodil) was a popular oil-based contrast agent used until late 1980s for myelography, ventriculography and cisternography. Although several long-term sequelae have been reported in literature, they are extremely rare. We report a rare occurrence of symptomatic dorsal arachnoid cyst 40 years after Myodil myelography.

Choroid plexus tumors: an institutional series of 25 patients.

PURPOSE: Choroid plexus tumors (CPT) are rare neoplasms that pose considerable treatment challenges. This study reviews a single institute's experience with 25 patients of CPT and attempts to contribute to the general body of knowledge on CPT. MATERIALS AND METHODS: A retrospective analysis of the case records of 25 patients operated for CPT since January 1998 and having a minimum of 1 year follow-up. RESULTS: The study group included 12 (48%) cases of choroid plexus papilloma (CPP), 09 (36%) cases of choroid plexus carcinoma (CPC) and 4 cases of atypical CPP. The mean age at presentation was 18.6 years (range, 6 months to 54 years; SD, 18.7) and a male preponderance was noted (17:8). Raised intracranial pressure was the commonest presenting symptom (72%). The tumors were distributed as follows: lateral ventricle (16; 64%), fourth ventricle (5; 20%), fourth ventricle with cerebellopontine angle extension (3; 12%), and third ventricle (1; 4%). A complete surgical excision was achieved in 11 cases of CPP and 8 cases of CPC. Operative complications include pneumocephalus (40%), focal deficits (36%), subdural effusion (32%), and persistent hydrocephalus requiring shunt (24%). All patients with CPP had a good outcome at the end of a mean follow-up of 5.4 years, whereas the median survival for patients with CPCs who underwent a subtotal resection with adjuvant therapy was 36 months. CONCLUSION: CPTs include a spectra ranging from CPP to CPC. Radiologic and histologic characterization of these tumors is difficult and newer immunohistochemical and genetic studies should be done to differentiate them from each other. Total excision offers a good prognosis and should be attempted for all forms of CPTs. CPPs carry a good prognosis, and adjuvant therapy is not indicated even after partial excision. CPCs and atypical CPCs carry a poor prognosis, and adjuvant therapy improves survival marginally after total excision. Spinal drop metastases are common for CPC and screening of the spine for possible metastasis should be part of the routine preoperative and postoperative investigation protocol.

Intracranial intradural aneurysmal bone cyst: a unique case.

Aneurysmal bone cyst (ABC) of the skull is exceedingly rare. We report a unique case of an intradural ABC without bone involvement presenting with raised intracranial pressure. The patient was a 14-year-old boy who presented with headache, vomiting and right focal seizure. Imaging showed a large multicystic left frontal lesion without any evidence of bone involvement. The lesion adherent to an intact sphenoid wing dura was completely excised. The histopathology report was consistent with an ABC. This case represents the first report of an ABC without involvement of the skull bones or any evidence of dural erosion. The possible mechanism of origin at this unusual location is hypothesized.