Stereotactic management of lesions of the pineal region

Machine learning-based classification of pineal germinoma from magnetic resonance imaging

Introduction

Surgical approaches for tissue diagnosis of pineal tumors have been associated with morbidity and mortality. The classification of images by machine learning (ML) may assist physicians in determining the extent of resection and treatment plans for a specific patient. Therefore, the present study aimed to evaluate the diagnostic performances of the ML-based models for distinguishing between pure and non-germinoma of the pineal area. In addition, the secondary objective was to compare diagnostic performances among feature extraction methods.

Methods

This is a retrospective cohort study of patients diagnosed with pineal tumors. We used the RGB feature extraction, histogram of oriented gradients (HOG), and local binary pattern methods from magnetic resonance imaging (MRI) scans; therefore, we trained an ML model from various algorithms to classify pineal germinoma. Diagnostic performances were calculated from a test dataset with several diagnostic indices.

Results

MRI scans from 38 patients with pineal tumors were collected and extracted features. As a result, the k-nearest neighbors (KNN) algorithm with HOG had the highest sensitivity of 0.81 (95% CI 0.78-0.84), while the random forest (RF) algorithm with HOG had the highest sensitivity of 0.82 (95% CI 0.79-0.85). Moreover, the KNN model with HOG had the highest AUC, at 0.845. Additionally, the AUCs of the artificial neural network and RF algorithms with HOG were 0.770 and 0.713, respectively.

Conclusions

The classification of images using ML is a viable way for developing a diagnostic tool to differentiate between germinoma and non-germinoma that will aid neurosurgeons in treatment planning in the future.

Benign and Malignant Tumors of the Pineal Region

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

Evaluation of the Perioperative and Postoperative Course of Surgery for Pineal Germinoma in the SIOP CNS GCT 96 Trial

Background: CNS germinoma, being marker-negative, are mainly diagnosed by histological examination. These tumors predominantly appear in the suprasellar and/or pineal region. In contrast to the suprasellar region, where biopsy is the standard procedure in case of a suspected germ-cell tumor to avoid mutilation to the endocrine structures, pineal tumors are more accessible to primary resection. We evaluated the perioperative course of patients with pineal germinoma who were diagnosed by primary biopsy or resection in the SIOP CNS GCT 96 trial. Methods: Overall, 235 patients had germinoma, with pineal localization in 113. The relationship between initial symptoms, tumor size, and postoperative complications was analyzed. Results: Of 111 evaluable patients, initial symptoms were headache (n = 98), hydrocephalus (n = 93), double vision (n = 62), Parinaud syndrome (n = 57), and papilledema (n = 44). There was no significant relationship between tumor size and primary symptoms. A total of 57 patients underwent primary resection and 54 underwent biopsy. Postoperative complications were reported in 43.2% of patients after resection and in 11.4% after biopsy (p < 0.008). Biopsy was significantly more commonly performed on larger tumors (p= 0.002). Conclusions: These results support the practice of biopsy over resection for histological confirmation of pineal germinoma.

Lateral Temporal Approach for Image-Guided Stereotactic Biopsy of Pineal Region Tumors

BACKGROUND

Biopsy of pineal region neoplasms is frequently accomplished by way of endoscopic transventricular access or using an image-guided, computer-assisted stereotactic approach.

METHODS

We evaluated a nonorthogonal lateral temporal approach for stereotactic biopsy of pineal region tumors as a variation of previously described stereotactic methods. Magnetic resonance imaging-guided frameless stereotaxy was used to plan and perform biopsies of pineal region tumors using a nonorthogonal trajectory extending from the superior or middle temporal gyri through the temporal stem, anterior to the atrium of the lateral ventricle, and posterior to the corticospinal tract.

RESULTS

All patients had an uncomplicated postoperative course and remained at neurologic baseline. No parenchymal or ventricular hemorrhage was present on postoperative scans. A tissue diagnosis was obtained in all patients.

CONCLUSIONS

This method appears to be a safe alternative to stereotactic biopsy using other trajectories and provides adequate tissue for definitive diagnosis.

Functional status of surgically treated pineal cyst patients

Background:

Microsurgical removal represents a well-accepted treatment option for symptomatic benign pineal cysts (PCs). However, very few studies have quantitatively evaluated the functional status of surgically treated PC patients.

Methods:

A detailed analysis of preoperative, immediate postoperative, and long-term clinical and radiological characteristics was performed. The functional status of the patients was categorized using the modified Rankin scale (mRS) and the Chicago Chiari Outcome Scale (CCOS). In addition, a comparative analysis between pediatric and adult patients with PCs was carried out.

Results:

Overall, pediatric patients experienced better long-term mRS scores than adults. The differences between the pre-, the immediate post-, and the last postoperative mRS of the patients were statistically significant for the total population (P < 0.001). All patients obtained a CCOS of 11 or more, which reflects a good/optimal result after microneurosurgery. The type of the surgical approach was independently associated with the postoperative complications (P < 0.01), more frequently reported with the midline supracerebellar infratentorial (SCIT) approach than with its paramedian modification.

Conclusion:

The functional status of properly selected symptomatic patients with PCs may improve significantly after their surgical management through a paramedian SCIT approach in sitting position.

Endoscopic Third Ventriculostomy and Simultaneous Tumor Biopsy in Pineal Region Tumors using the "Single Burr Hole" Technique: An Analysis of 34 Cases

Background

Pineal region tumors often present with hydrocephalus. Endoscopic third ventriculostomy (ETV) and simultaneous tumor biopsy remain a minimally invasive procedure offering both diagnostic and therapeutic advantages in the management of these tumors. However, different operative techniques have been described in the literature.

Aim

The aim is to study the ETV success rate, diagnostic rate of simultaneous tumor biopsy, complications, and follow-up of patients of pineal region tumors managed with ETV and simultaneous tumor biopsy using the single burr hole technique.

Methods

The study was performed by retrospectively reviewing the records of patients of pineal region tumors managed by simultaneous ETV and tumor biopsy using a "single burr hole" technique from January 2012 to December 2019.

Results

Thirty-four patients (22 males and 12 females) with a mean age of 28.7 years were analyzed. ETV was successful in relieving hydrocephalus in 29 (87.8%) patients. Three patients needed a ventriculoperitoneal shunt, and one required Ommaya reservoir placement for persistent hydrocephalus. Histological diagnosis was successfully established in 26 (78.8%) patients. There were two procedure-related mortalities. Two patients underwent craniotomy and tumor excision subsequently. Radiotherapy was given to 11 patients, and 9 patients were managed by observation alone. The mean follow-up of our study was 15.8 months.

Conclusions

Simultaneous ETV and tumor biopsy using a single burr hole technique is a safe, minimally invasive procedure for the management of pineal region tumors.

Surgical approaches in pediatric neuro-oncology

Tumors of the central nervous system comprise nearly a quarter of all childhood cancers and are the most frequent solid tumor in the pediatric population. The most common location is in the posterior fossa, but tumors can occur anywhere intracranially. The spectrum of lesions encountered varies, from being completely benign and requiring surveillance alone to being highly malignant and requiring aggressive treatment in the form of surgery and adjuvant therapy. The extent of resection plays a crucial role in the oncological outcome of many of these tumors. A variety of surgical approaches are available for the spectrum of lesions encountered. This review focuses on summarizing the location, types, and neurosurgical management strategies for pediatric brain intracranial brain tumors. Here, we discuss neurosurgical approaches for a variety of brain tumors and regions, including the management of tumors of the posterior fossa, brainstem, pineal region, intraventricular region, sellar and suprasellar regions, optic pathway and hypothalamus, and supratentorial hemispheres.

Systematic review of pineal cysts surgery in pediatric patients

INTRODUCTION

We present a consecutive case series and a systematic review of surgically treated pediatric PCs. We hypothesized that the symptomatic PC is a progressive disease with hydrocephalus at its last stage. We also propose that PC microsurgery is associated with better postoperative outcomes compared to other treatments.

METHODS

The systematic review was conducted in PubMed and Scopus. No clinical study on pediatric PC patients was available. We performed a comprehensive evaluation of the available individual patient data of 43 (22 case reports and 21 observational series) articles.

RESULTS

The review included 109 patients (72% females). Ten-year-old or younger patients harbored smaller PC sizes compared to older patients (p < 0.01). The pediatric PCs operated on appeared to represent a progressive disease, which started with unspecific symptoms with a mean cyst diameter of 14.5 mm, and progressed to visual impairment with a mean cyst diameter of 17.8 mm, and hydrocephalus with a mean cyst diameter of 23.5 mm in the final stages of disease (p < 0.001). Additionally, 96% of patients saw an improvement in their symptoms or became asymptomatic after surgery. PC microsurgery linked with superior gross total resection compared to endoscopic and stereotactic procedures (p < 0.001).

CONCLUSIONS

Surgically treated pediatric PCs appear to behave as a progressive disease, which starts with cyst diameters of approximately 15 mm and develops with acute or progressive hydrocephalus at the final stage. PC microneurosurgery appears to be associated with a more complete surgical resection compared to other procedures.

Pineal Region Gliomas: A Single-Center Experience with 25 Cases

BACKGROUND

Pineal region glioma is a rare systematically reported tumor in the literatures, and little is known about its behavior, development, and best treatment strategies because of its complex anatomical relationship and rarity.

OBJECTIVE

We reviewed the outcomes of patients with pineal region gliomas in West China hospital in the past 5 years and searched the literature to add more information. As a result, key factors related to prognosis are identified.

METHODS

Twenty-five patients with pineal region gliomas were selected and information was collected about detailed medical history, imaging data, treatment methods, pathologic results, and latest neurosurgical radiologic progress during follow-up.

RESULTS

Pilocytic astrocytomas (20%) and glioblastomas (24%) were the most common pathologic subtypes. Twenty-three patients underwent open surgery, 3 Gamma Knife radiosurgery, and 4 whole-brain radiation therapy. Chemotherapy was applied to 3 patients. Low-grade gliomas tended to have a better prognosis than did high-grade. Karnofsky Performance Status at admission (≤60) was intimately associated with prognosis for low-grade gliomas. As for high-grade gliomas, patients whose age at admission was ≤30 years had a better prognosis than did older patients (＞30 years). However, whatever the grade, there was no overall survival difference as to gender, gross total resection versus not gross total resection, preoperative maximal tumor diameter (≤4 vs. ＞4 cm), and time since first symptoms (≤30 vs. ＞30 days), and radiation therapy versus no radiation therapy.

CONCLUSIONS

Open surgery is the first-line strategy for pineal region gliomas with tolerable mortality and disability rate. Radiosurgery and chemotherapy can be applied as adjuvant or alternative methods when surgery is contraindicated.

The microsurgical management of benign pineal cysts: Helsinki experience in 60 cases

Background:

Microsurgical resection represents a well-accepted management option for symptomatic benign pineal cysts. Symptoms such as a headache, hydrocephalus, and visual deficiency are typically associated with pineal cysts. However, more recent studies reported over the past years have characterized additional symptoms as a part of the clinical manifestation of this disease and represent additional indications for intervention.

Methods:

We present a retrospective review of patients with histologically confirmed benign pineal cysts that were operated on in our department between 1997 and 2015. A demographic analysis, evaluation of preoperative status, surgical treatment, as well as immediate and long-term clinical and radiological outcomes were conducted.

Results:

A total of 60 patients with benign pineal cysts underwent surgery between 1997 and 2015. Gross total resection was achieved in 58 cases. All patients except one improved in their clinical status or had made a full recovery at the time of the last follow-up. The key steps for surgical resection of pineal cysts are reported, based on an analysis of representative surgical videos.

Conclusions:

We describe in this paper one of the largest series of microsurgically treated pineal cysts. In our opinion, judicious microsurgery remains the most suitable technique to effectively deal with this disease.

Is surgery for pineal cysts safe and effective? Short review

In this short review, the authors performed a database search and summarize current knowledge of the management of patients with pineal cysts (PCs) and investigate the role of surgical treatment. The scientific literature on the surgical treatment of PCs is sparse and encompasses only case series with little over 200 operated patients combined. All included papers reported favorable results after pineal cyst surgery with improvement of symptoms in most patients. Microsurgical resection of PCs, preferably using the supracerebellar-infratentorial approach, could be considered as a viable treatment option in symptomatic patients. Even patients with non-specific symptoms are reported to improve after surgery. However, evidence offered by this literature review is very limited and therefore our conclusions must be tempered by the restricted set of data. For ethical reasons, a randomized controlled trial is not an acceptable approach, and therefore patient registry could be a useful tool to identify a subset of symptomatic patients that might benefit from pineal cyst resection.

[Pineal cyst]

A pineal cyst (PC) is a benign neoplasm in the pineal region, or more precisely in the pineal body. Most cysts are incidental findings and are not associated with symptoms typical of patients seeking medical advice. Symptomatic cysts are discovered less often and, depending on the clinical picture, require different treatment approaches.

MATERIAL AND METHODS

We analyzed the literature data about the clinical picture, diagnosis, and treatment of PCs for more than a century (1914-2016).

CONCLUSION

To date, there is no single approach for managing PC patients. The indications for surgical treatment of symptomatic PCs are still not fully defined. It remains unclear which PC cases should be followed-up, and how often control examinations should be performed. More research of PCs is needed to develop new approaches to treatment of PC patients.

Microsurgical resection of pineal region tumors

The extensive variety of possible histologic subtypes makes it imperative to establish a tissue diagnosis in patients with pineal region tumors. Management decisions regarding adjuvant therapy, prognosis, and follow-up strategies vary with the histologic diagnosis. Specialized surgical and stereotactic techniques have evolved to provide the neurosurgeon with an array of safe and effective options for obtaining a tissue diagnosis. Advanced microsurgical techniques combined with improved preoperative management and postoperative critical care methods have made aggressive surgical resection a mainstay of management. Aggressive surgical resection has resulted in excellent long-term prognoses for nearly all patients with benign tumors and a large percentage of patients with malignant tumors. However, pineal region surgery remains fraught with potential pitfalls, and these favorable results are dependent on an advanced level of surgical expertise.

Clinical management of pineal cysts: a worldwide online survey

BACKGROUND

A pineal cyst is a benign affection of a pineal gland on the borderline between a pathological lesion and a variant of normality. Clinical management of patients with a pineal cyst remains controversial, especially when patients present with non-specific symptoms.

METHODS

An online questionnaire consisting of 13 questions was completed by 110 neurosurgeons worldwide. Responses were entered into a database and subsequently analysed.

RESULTS

Based on data from the questionnaire, the main indication criteria for pineal cyst resection are hydrocephalus (90 % of the respondents), Parinaud's syndrome (80 %) and growth of the cyst (68 %). Only 15 % of the respondents occasionally operate on patients with non-specific symptoms. If surgery is indicated, improvement is expected in 88 % of the patients. The vast majority of the respondents favour a supracerebellar infratentorial approach to the pineal region. Most (78 %) of the respondents regarded the patient registry as a potentially useful instrument.

CONCLUSIONS

This survey sheds light on the current practice of pineal cyst management across the world. Most of the respondents perform surgery on pineal cysts only if patients are presenting with symptoms attributable to a mass effect. Surgery for patients with non-specific complaints (headache, vertigo) is not widely accepted, although it may prove effective. A prospective patient registry might be useful in the decision-making process in the clinical management of pineal cysts.

Pineal lesions: a multidisciplinary challenge

The pineal region is a complex anatomical compartment, harbouring the pineal gland surrounded by the quadrigeminal plate and the confluents of the internal cerebral veins to form the vein of Galen. The complexity of lesions in that region, however, goes far beyond the pineal parenchyma proper. Originating in the pineal gland, there are not only benign cysts but also numerous different tumour types. In addition, lesions such as tectal gliomas, tentorial meningiomas and choroid plexus papillomas arise from the surrounding structures, occupying that regions. Furthermore, the area has an affinity for metastatic lesions. Vascular lesions complete the spectrum mainly as small tectal arteriovenous malformations or cavernous haemangiomas.Taken together, there is a wide spectrum of lesions, many unique to that region, which call for a multidisciplinary approach. The limited access and anatomical complexity have generated a spectrum of anatomical approaches and raised the interest for neuroendoscopic approaches. Equally complex is the spectrum of treatment modalities such as microsurgery as the main option but stereotactic radiosurgery as an alternative or adjuvant to surgery for selected cases, radiation as for germinoma (see below) and or combinatorial chemotherapy, which may need to precede any other ablative technique as constituents.In this context, we review the current literature and our own series to obtain a snapshot sentiment of how to approach pineal lesions, how to interrelate alternative/competing concepts and review the recent technological advances.

Endoscopic versus stereotactic procedure for pineal tumour biopsies: Comparative review of the literature and learning from a 25-year experience

BACKGROUND AND PURPOSE

Pineal tumours account for 1% to 4% of brain tumours in adults and for around 10% in children. Except in a few cases where germ cell markers are elevated, accurate histological samples are mandatory to initiate the treatment. Open surgery still has a high morbidity and is often needless. Biopsies can either be obtained by endoscopic or stereotactic procedures.

METHODS

Following an extensive review of the literature (PubMed 1970-2013; keywords pineal tumour, biopsy; English and French), 33 studies were analysed and relevant data compared regarding the type of procedure, diagnosis rate, cerebrospinal fluid diversion type and rate, perioperative mortality, morbidity.

RESULTS

Endoscopic and stereotactic biopsies showed a diagnosis rate of 81.1% (20%-100%) and 93.7% (82%-100%), respectively. Endoscopic biopsies involved 21.0% of minor and 2.0% of major complications whereas stereotactic biopsies involved 6.4% of minor and 1.6% of major complications. The most frequently reported complication was haemorrhage for both endoscopic and stereotactic procedures, accounting for 4.8% and 4.3%, respectively. Mortality rate was low for both endoscopic and stereotactic procedures, equal to 0.4% and 1.3%, respectively. Local experience of stereotactic biopsies was also reported and corroborated the previous data.

CONCLUSIONS

The difference between both procedures is not statistically significant (p>0.05) across large series (≥20patients). Nevertheless, tissue diagnosis appears less accurate with endoscopic procedures than with stereotactic procedures (81.1% versus 93.7%, weighted mean across all series). In our opinion, the neuroendoscopic approach is the best tool for managing hydrocephalus, whereas stereotactic biopsies remain the best way to obtain a tissue diagnosis with accuracy and low morbidity.

Endoscopic surgery for hemorrhagic pineal cyst following antiplatelet therapy: case report

Pineal cysts of the third ventricle presenting with acute obstructive hydrocephalus due to internal cystic hemorrhage are a rare clinical entity. The authors report a case of a 61-year-old man taking antiplatelet medication who suffered from a hemorrhagic pineal cyst and was treated with endoscopic surgery. One month prior to treatment, the patient was diagnosed with a brainstem infarction and received clopidogrel in addition to aspirin. A small incidental pineal cyst was concurrently diagnosed using magnetic resonance (MR) imaging which was intended to be followed conservatively. The patient presented with a sudden onset of headache and diplopia. On admission, the neurological examination revealed clouding of consciousness and Parinaud syndrome. Computerized tomography (CT) scans demonstrated a hemorrhagic mass lesion in the posterior third ventricle. The patient underwent emergency external ventricular drainage with staged endoscopic biopsy and third ventriculostomy using a flexible videoscope. Histological examination revealed pineal tissue with necrotic change and no evidence of tumor cells. One year later MR imaging demonstrated no evidence of cystic lesion and a flow void between third ventricle and prepontine cistern. In patients with asymptomatic pineal cysts who are treated with antiplatelet therapy, it is important to be aware of the risk of pineal apoplexy. Endoscopic management can be effective for treatment of hemorrhagic pineal cyst with obstructive hydrocephalus.

Update on the management of pineal cysts: Case series and a review of the literature

OBJECTIVE

The natural history of pineal cysts still remains unclear. Incidental pineal cysts have become more common which raises the question of their management. Symptomatic pineal cysts may require a surgical solution but therapeutic indications have not yet been clearly established.

METHOD

From 1986 to 2012, 26 patients with pineal cysts were identified. Their medical records were retrospectively assessed focusing on the initial symptoms, imaging characteristics of the cyst, management strategy, operative technique and their complications, as well as the latest follow-up. A systematic review of the literature is also presented.

RESULTS

Twenty-six patients with pineal cysts were identified. The mean age was 23.5 years ranging from 7 to 49 years. Symptoms included intracranial hypertension with obstructive hydrocephalus in 18 cases and oculomotor anomalies in 12 cases. Two adult cases presented with non-specific headaches and did not require surgery. Twenty patients were operated via a suboccipital transtentorial approach with total removal of the cyst in 70% of the cases, while the remaining 4 cases were treated with an intraventricular endoscopic marsupialization associating a third ventriculostomy. Four patients required a preoperative ventriculo-peritoneal shunt due to life-threatening obstructive hydrocephalus. Overall, peri-operative mortality was nil. In the two non-operated patients, the cyst remained stable and no recurrences were observed in all operated patients with a mean follow-up of 144 months.

CONCLUSION

In the majority of incidental pineal cysts, a clinical and imaging follow-up is sufficient but occasionally not required especially in adults as very rare cases of increase in size have been reported.

Gliomas of the pineal region

Although several series of pineal region tumors are available, the issue of pineal gliomas has been scarcely faced in the literature. Gliomas are usually included in largest series of pineal neoplasms. Therefore, whether pineal gliomas share the biological behavior of either hemispheric gliomas or other midline lesions is not yet defined. The aim of this retrospective study is to analyze long-term morbidity and mortality of these lesions. In English published literature gliomas account for about 14-22 % of all pineal region tumors. Most of these tumors are pilocytic astrocytomas, while glioblastoma multiforme is rare. We retrospectively analyzed all pineal region tumors operated on in our department in the last 28 years, and identified eight pineal astrocytomas, accounting for 14.03 % of all pineal tumors. The series includes four pilocytic astrocytomas, two grade II diffuse astrocytomas, and two anaplastic astrocytomas. A comprehensive review of the available literature data shows that the mean survival time of WHO grade II gliomas is shorter when tumor grows in the pineal region than for hemispheric locations, although the limited amount of available data prevents a rigorous statistical analysis. This difference might be due to the peculiar infiltrating behavior of pineal tumors, which often can't be satisfactorily resected from vital structures.

Pineal cysts in children: case-based update

PURPOSE

Pineal cysts (PC) are found in children as often asymptomatic and without change in their size over the time. However, there are some debatable issues about their evolution and management in the pediatric population. The aim of the present paper is to update the information regarding pathogenesis, clinical presentation, and management of these lesions.

METHODS

All the pertinent literature was reviewed, and a meta-analysis of operated on cases was carried out. An illustrative case regarding the clinical evolution of a 13-year-old girl is also presented.

RESULTS AND CONCLUSIONS

PC are often asymptomatic and do not evolve over the time. However, since there is a certain risk of clinical and/or radiological progression, or even sudden and severe clinical onset (apoplexy), both a clinical and radiological follow-up is recommended in the pediatric age. The surgical excision is usually limited to symptomatic patients or to cases with clear radiological evolution.

Surgical pathway and management of pineal region tumours in children

BACKGROUND

Pineal region tumours are rare. Surgery is associated with high morbidity, and consensus on ideal management pathways remains variable.

METHOD

Patients with pineal region tumours were identified from the neuro-oncology database, and their data were retrospectively reviewed. Data collection included presentation, germ cell markers, tumour size and location, imaging, histology, treatment and control/relapse rates.

RESULTS

Twenty-four patients were treated at Alder Hey Children's Hospital between 1998 and 2010. Median age at diagnosis was 12.7 years. Sixteen patients presented with hydrocephalus. Twelve were successfully treated with endoscopic third ventriculostomy (EVT), and four required shunt insertion during follow-up. Fifteen patients had endoscopic biopsies. Eleven biopsies were performed at the same time as third ventriculostomy, and four patients without significant hydrocephalus had endoscopic image-guided biopsies. Eight patients had stereotactic biopsies (either because of slit ventricles at diagnosis or because of a ventriculoperitoneal shunt already in place), and only one patient had an open biopsy. No morbidity or mortality was associated with the biopsies. Histology showed four pineal parenchymal tumours, nine gliomas and eleven germ cell tumours. Thirteen patients underwent surgical resection. Significant tumour debulking was achieved in all of these patients, with gross total resection in 70 % of cases. There was one intraventricular haemorrhage (full recovery) and one mild hemiparesis. There was no surgical mortality.

CONCLUSION

The mainstay of hydrocephalus management is EVT which provides a safe and reliable route for biopsy. In our experience, craniotomy and tumour resection are effective and safe.

Pediatric considerations for pineal tumor management

Pineal tumors are relatively rare central nervous system lesions with a predilection for the pediatric population. For the vast majority of these lesions, surgical resection is a critical step in effective treatment. This article discusses current strategies for preoperative evaluation, operative management, and postoperative care of the pediatric patient with a newly diagnosed pineal region tumor.

Pineal parenchymal tumor of intermediate differentiation with marked elevation of MIB-1 labeling index

We report a case of pineal parenchymal tumor (PPT) in an 11-year-old girl. Brain magnetic resonance imaging (MRI) revealed a large tumor (48 mm) located in the pineal region with heterogeneous enhancement after gadolinium administration. The patient underwent tumor removal with craniotomy; only partial tumor resection could be performed because of massive intratumoral bleeding. Histopathological examination of the tumor showed lobular proliferation of round cells with moderate atypia. Cellularity varied by area, and focal Homer Wright rosettes were identified. Examination of tumor cells revealed a few mitoses (two mitotic figures per 10 high-powered fields), and immunohistochemical staining revealed positivity for synaptophysin, slight positivity for neurofilament protein (NFP) with antibody clone 2F11, and strong positivity for NFP with clone NF-M+H. The pathological diagnosis was pineal parenchymal tumor of intermediate differentiation grade II according to World Health Organization criteria despite a high (22%) MIB-1 labeling index (LI). The patient had a favorable clinical course after an intensified chemotherapy regimen designed for pineoblastoma and radiotherapy administered to the entire neuraxis, followed by stereotactic radiotherapy. In conclusion, MIB-1 LI could be a useful tool for deciding therapeutic strategies for PPT treatment when there is a discrepancy between clinical findings and pathological grading.

Microsurgical third ventriculostomy with stenting in intrinsic brain tumors involving anterior third ventricle

OBJECTIVE

Microsurgical fenestration of the third ventricular floor performed in one session with resection of deep seated tumors has been recently demonstrated as an approach to specifically address the concomitant obstructive hydrocephalus. As with endoscopic third ventriculostomy, occlusion of the stoma may result in progression of the obstructive hydrocephalus. In order to provide reliable communication between the basal cisterns and ventricles, we propose stenting of the stoma in cases of direct surgical approach to deep seated tumors.

METHODS

After performing tumor resection through the anterior transcallosal approach, premamillar and Liliequist's membranes were identified and fenestrated. A silicon stent was inserted into the prepontine cistern through the fenestrated floor of the third ventricle; the stent connected the third and lateral ventricles with the basal cisterns.

RESULTS

Microsurgical ventriculostomy of the third ventricle and stenting of the stoma was performed in 9 patients simultaneously with tumor resection (5 cases), open biopsy (3 cases), or microsurgical dissection of severe adhesions at the level of Monro foramina (1 case). In 7 cases, the third ventricular floor was infiltrated with the tumor and obstruction of the aqueduct persisted after tumor surgery; in 2 patients, high risk of reocclusion at the level of Monro foramen was expected. Stenting of the ventricular system provided patency of the stoma and Monro foramen. None of the patients required a shunt postoperatively. The follow-up time ranged from 3 to 22 months.

CONCLUSION

Microsurgical fenestration of the third ventricle floor combined with stoma stenting can be a viable option for hydrocephalus control.

Tumors of the posterior third ventricular region in pediatric patients: The Indian perspective and a review of literature

Background:

Diverse tumors in the posterior third ventricular region (TPTVR) frequently occur in children. A decade's experience with pediatric TPTVR is presented, focusing on the Indian perspective.

Materials and Methods:

25 children (age range: 3-18 years; mean age: 13.32 years; presentation range: 7 days-2.5 years) had clinico-radiological assessment with contrast computed tomography (CT) and magnetic resonance imaging (MRI). The ventricular/lumbar cerebrospinal fluid (CSF) alpha feto protein (AFP)/beta human chorionic gonadotrophin (HCG) estimation was done when radiological suspicion of a germ cell tumor was present. Extent of resection was deemed partial when some tumor mass remained at the end of surgery, near total when <10% was retained over vital neurovascular structures, and total when complete resection was attained.

Results:

Operations included infratentorial supracerebellar approach (n = 12), occipito-transtentorial approach (n = 2), endoscopic biopsy and third ventriculostomy (n = 1), frontal parasagittal craniotomy, interhemispheric transcallosal subchoroidal approach (n = 2), middle temporal gyrus transcortical transventricular approach (n = 1), fronto-temporo-zygomatic combined transylvian and subtemporal approach (n = 1) and right ventriculoperitoneal shunt and stereotactic biopsy (n = 1). Only CSF diversion was performed for five patients with a small TPTVR. CSF diversion was required in 12 (48%) patients. Tumor pathology included pinealoblastoma (n = 4; one with pineocytic differentiation), nongerminomatous germ cell tumor (NGGCT; n = 3), germinoma (n = 3), pilocytic astrocytoma (n = 2), epidermoid (n = 3) and primitive neuroectodermal tumor (PNET), fibrillary astrocytoma, glioblastoma, teratoma, and meningioma (n = 1, respectively). A patient with neurocysticercosis was diagnosed solely on MRI (four did not undergo biopsy). Fractionated radiotherapy was administered in 13 patients with primary pineal tumors, PNET, NGGCT, fibrillary astrocytoma and glioblastoma. Extent of excision was total in 10 (40%), near total in 5 (20%), partial in 3 (12%) and a biopsy in 2 (8%) patients.

Conclusions:

Histopathologic characterization of TPTVR is essential prior to their further management. Benign lesions often have a good prognosis following gross total surgical resection. Pure germinomas are highly susceptible to radiotherapy. NGGCTs often have malignant components that require adjuvant therapy following surgery. The advancements in microsurgical techniques have led to gratifying perioperative results in these deep-seated lesions.

Nationwide investigation of the current status of therapeutic neuroendoscopy for ventricular and paraventricular tumors in Japan

OBJECT

The authors report their investigation on the current status of neuroendoscopic biopsy for ventricular and paraventricular tumors as well as treatment for associated hydrocephalus in Japan.

METHODS

Patients who had undergone therapeutic neuroendoscopy between 2005 and 2009 were included in this study. The main items examined were age; sex; localization of tumor; pathological diagnosis using biopsy; the presence, treatment, and efficacy of treatment of associated hydrocephalus; perioperative complications; activities of daily living (ADL) before and after therapeutic neuroendoscopy; and the presence of dissemination during the postoperative course.

RESULTS

Seven hundred fourteen patients from 123 sites (462 male and 252 female patients, mean age 33.3 years) were enrolled. Localization of the tumor was mainly classified into the lateral ventricle in 91 patients, the third ventricle in 339, the fourth ventricle in 18, the suprasellar region in 75, and other paraventricular areas in 191 patients. The most commonly observed tumors were germ cell tumors in the third ventricle (177 cases [39%]), cystic lesions in the suprasellar region (56 cases [75%]), and astrocytic tumors in the thalamus-basal ganglia (71 cases [38%]). Although 641 (92.8%) of 691 patients could receive neuroendoscopic diagnosis using biopsy, the diagnosis obtained with endoscopic biopsy differed from the final diagnosis based on subsequent craniotomy in 18 patients and clinical course in 3 patients. Of these 21 patients, 7 had astrocytic tumors, 4 had pineal tumors, 6 had germ cell tumors, and 4 had other tumors. The final diagnostic accuracy rate was 89.7%. Associated hydrocephalus was observed in 517 patients (72.4%), of whom 316 and 39 underwent third ventriculostomy and fenestration of the septum, respectively. The response rates were 96.2% and 89.7%, respectively. Third ventriculostomy was required for recurrence of hydrocephalus in 41 patients (13.0%), and the long-term response rate was therefore 83.2% (263 of 316 patients). Perioperative complications other than fever, such as new onset of or progressive hydrocephalus, infection due to CSF leakage, and bleeding in the ventricle or tumor, were found in 81 patients (11.3%). The median Karnofsky Performance Scale score before endoscopic surgery was 80, but it increased to 90 after surgery. The score was thus significantly increased after surgery (p < 0.0001, Mann-Whitney U-test). Activities of daily living after surgery decreased due to perioperative complications in 15 patients (2.1%). The incidence of new dissemination after endoscopic biopsy was 6.8% and not high compared with routine surgical treatment.

CONCLUSIONS

The authors concluded that neuroendoscopic diagnosis using biopsy for ventricular and paraventricular tumors is adequately accurate and safe. It was demonstrated that endoscopic procedures play important roles not only in the treatment of hydrocephalus associated with intra- and paraventricular tumors but also in significantly improving ADL. Furthermore, the long-term outcome of endoscopic third ventriculostomy was clearly favorable.

Are stereotactic sample biopsies still of value in the modern management of pineal region tumours? Lessons from a single-department, retrospective series

OBJECTIVE

Recent improvements in imaging-based diagnosis, the broader application of neuroendoscopic techniques and advances in open surgery techniques mean that the need for stereotactic biopsies in the management of pineal region tumours must be reevaluated. The primary aim of this retrospective study was to establish whether stereotactic biopsy is still of value in the modern management of pineal region tumours.

METHODS

From 1985 to 2009, 88 consecutive patients underwent a stereotactic biopsy in our institution (51 males and 37 females; median age at presentation 30; range 2-74).

RESULTS

Accurate tissue diagnoses were obtained in all but one case (i.e. 99%). In one case (1%), three distinct stereotactic procedures were necessary to obtain a tissue diagnosis. There was no mortality or permanent morbidity associated with stereotactic biopsy. One patient (1%) presented an intra-parenchymal hematoma but no related clinical symptoms. Five patients (6%) presented transient morbidity, which lasted for between 2 days and 3 weeks after the biopsy.

CONCLUSIONS

To guide subsequent treatment, we believe that histological diagnosis is paramount. Stereotactic biopsies are currently the safest and the most efficient way of obtaining this essential information. Recent improvements in stereotactic technology (particularly robotic techniques) appear to be very valuable, with almost no permanent morbidity or mortality risk and no decrease in the accuracy rate. In our opinion, other available neurosurgical techniques (such as endoscopic neurosurgery, stereotactic neurosurgery and open microsurgery) are complementary and not competitive.

Transcallosal interforniceal approach to pineal region tumors in 150 children

OBJECT

Pediatric pineal region tumors are very difficult to cure surgically. The authors used the transcallosal interforniceal approach in patients with these lesions.

METHODS

One hundred fifty children, 98 boys and 52 girls, with pineal region tumors underwent tumor resection via the transcallosal interforniceal approach in the pediatric neurosurgery ward of TianTan Hospital. The patients ranged in age from 1 to 15 years. Fifty-eight patients had mature teratomas; 57, immature teratomas; 14, astrocytomas; 3, glioblastomas; 4, pineoblastomas; 2, pineocytomas; 4, choriocarcinomas; 4, cavernous hemangiomas; 2, germ cell tumors; and 2, epidermoid cysts.

RESULTS

One hundred twenty-nine tumors were totally removed, 15 were subtotally removed, and 6 were partly removed. There were no deaths and no subsequent instances of disconnection syndrome. Short-term memory deficits appeared in 94 patients but resolved within 6 months in most; only a few patients retained persistent deficits. There were 2 patients with mutism that resolved within 10 days. Parinaud syndrome was observed in 45 patients after surgery; 21 of these cases had appeared preoperatively. The syndrome resolved within 6 months in 31 patients, while it remained in the other 14.

CONCLUSIONS

The transcallosal interforniceal approach appears to be a safe route for pineal region tumors in children, and complete resection can be achieved in the majority of patients.

Metastatic pineal tumors treated by neuroendoscopic surgery--two case reports

Two patients presented with metastatic pineal tumors. A 69-year-old man had gait disturbance, dementia, and urinary incontinence but no history of previous malignancy. Magnetic resonance imaging of the brain revealed a 23-mm tumor in the pineal region and obstructive hydrocephalus. A 37-year-old man had been treated for thyroid cancer. He presented with vomiting and consciousness disturbance. Brain magnetic resonance imaging revealed a 28-mm pineal tumor associated with intratumoral hemorrhage and accompanying obstructive hydrocephalus. Both patients underwent neuroendoscopic biopsy and third ventriculostomy through the foramen of Monro, resulting in reliable histological diagnoses and subsidence of hydrocephalus.

Balloon compression technique in the management of persistent intraoperative intratumoral hemorrhage resulting from stereotactic biopsy: technical note

BACKGROUND

Despite its proven safety, intraoperative intratumoral hemorrhage is an uncommon but serious complication of stereotactic brain biopsy.

OBJECTIVE

We describe the "balloon compression technique" that was used in the management of persistent intraoperative bleeding that could not be arrested by conventional methods of hemostasis.

METHODS

Between January 2001 and March 2009, of 184 image-guided stereotactic brain biopsy procedures, intraoperative intratumoral bleeding occurred in 12 cases (6.5%). In 3 of these 12 cases (1.6%), intraoperative hemorrhage was persistent. In these cases, after adjustment of the optimum length, a balloon catheter (Fogarty) was inserted through the cannula and inflated with a contrast agent. We observed the patient for 10 minutes by checking the position of the balloon with regular intervals, using a frozen C-arm fluoroscope to determine any significant changes in its initial position due to possible enlargement of the hematoma. The patient was also closely observed during this time.

RESULTS

Hemostasis was obtained immediately after the inflation of the balloon in all 3 cases. The patients tolerated the procedure well. During and after the procedure no complications related to the technique were observed. None of the cases required craniotomy for evacuation of the hematoma and to secure hemostasis.

CONCLUSION

Our preliminary results indicate that the balloon compression technique seems to be a safe, rapid, and effective stereotactic practice in the management of the persistent intraoperative intratumoral bleeding that could not be arrested by standard, conventional hemostatic methods.

Pineal parenchymal tumors. Management with interstitial iodine-125 radiosurgery

PURPOSE

To evaluate the efficacy of interstitial radiosurgery (IRS) for pineal parenchymal tumors (PPTs).

PATIENTS AND METHODS

18 consecutively admitted patients (twelve male and six female, age range 6-68 years, median age 34 years) with PPTs (eight pineocytomas, ten malignant PPTs) were treated at the authors' institution with IRS using stereotactically guided iodine-125 seed implantation ((125)I-IRS) as either primary or salvage therapy. The cumulative tumor surface dose ranged from 40 to 64 Gy. Adjuvant radiotherapy of the whole brain or the craniospine was done in patients with grade III and grade IV PPT. The median follow-up period was 57.4 months (range 6-134 months).

RESULTS

Overall actuarial 5- and 8-year survival rates after IRS were 100% and 86% for pineocytomas, and the overall actuarial 5-year survival rate was 78% for high-grade PPTs. Follow-up magnetic resonance imaging showed complete remission in 72% (13/18) and partial remission in 28% (5/18) of the cases. One patient developed an out-of-field relapse 4 years after partial remission of a pineocytoma, which had already been treated with IRS. There was no treatment-related mortality. Treatment-related morbidity occurred in two patients only.

CONCLUSION

This study indicates that stereotactic (125)I-IRS for the management of PPTs is quite efficient and safe. Due to the low rate of side effects, IRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant PPTs, IRS may be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.

Primary midbrain germinoma

Intracranial germinomas arising primarily in the midbrain are extremely rare and only one case has been reported in the literature. A 15-year-old boy presented with headache, diplopia, unsteadiness and personality changes. Brain MRI showed a heterogeneous lesion in the midbrain. The pineal body region was free. The preoperative diagnosis included brain-stem glioma, metastasis and lymphoma. Stereotactic biopsy was permitted in order to take a specimen and the diagnosis of germinoma was established. The patient responded well to chemotherapy and radiotherapy. Germinoma should be included in the differential diagnosis of midbrain lesions. Preoperative diagnosis is difficult and biopsy is still needed for such lesions.

Endoscopic biopsy during third ventriculostomy in paediatric pineal region tumours

OBJECTS

The goal of the study was to establish if endoscopic biopsy during third ventriculostomy contributes to morbidity in the management of paediatric pineal region tumours presenting with hydrocephalus.

MATERIALS AND METHODS

This study was a retrospective descriptive study in patients less than 18 years of age who have presented with a pineal region tumour between 2000 and 2006. Data were obtained from case notes. Twelve patients had presented with a pineal region mass with symptomatic hydrocephalus. Of these, eight had endoscopic biopsy during third ventriculostomy.

CONCLUSIONS

No mortality or permanent morbidity was seen following endoscopic biopsy. Two cases of transient worsening of pre-operative diplopia were noted. Diagnostic sensitivity for endoscopic biopsy is 75%. Tumour markers were not significantly raised in any plasma and cerebrospinal fluid samples. Endoscopic biopsy during third ventriculostomy in paediatric pineal region tumours is safe and results in good diagnostic yields. It should play an integral role in the initial management of patients in this setting.

Intracranial teratomas in children: the role and timing of surgical removal

OBJECT

In this study, the authors report their experience with the surgical treatment of intracranial teratomas with an emphasis on the indications for delayed resection after oncological treatment.

METHODS

The authors retrospectively reviewed the cases of 14 children with intracranial teratomas. The mean age at diagnosis was 10.5 years (range 2 days-18 years), and 11 patients were male. The final histological analysis revealed pure mature teratoma in 5 cases, mixed teratoma with germinoma in 3 cases, and nongerminomatous malignant germ cell tumor in 6 cases. Thirteen patients underwent tumor resection, and these patients were divided into 2 subgroups according to the timing of surgery. In Group A, 10 patients underwent resection as the primary treatment because no tumor markers were detected in 4 patients, a teratomatous component was revealed on biopsy sampling in 3 patients, and a large tumor volume in 3 patients. In Group B, 3 patients underwent removal of residual pure mature teratoma after oncological treatment.

RESULTS

Seven of the 8 patients (87.5%) with pure mature teratomas or with mixed teratoma and germinoma are currently alive (mean follow-up of 9 years); the eighth patient died of postoperative meningitis. Two of the 6 patients (33%) with mixed nongerminomatous malignant germ cell tumors died of tumor progression regardless of the timing of surgery.

CONCLUSIONS

The results of this study support the belief that microsurgical removal is the only effective treatment for intracranial teratomas. Surgery may be performed as the primary therapy when there is evidence of a noninvasive teratoma, and as a secondary therapy if there is only a partial response to neoadjuvant therapy or if progression is observed in mixed malignant germ cell tumors.

Endoscopic options in management of posterior third ventricular tumors

OBJECTIVE

A spectrum of both radiosensitive and radio-resistant lesions occurs in the region of the posterior third ventricle (PTV). Most of these are associated with hydrocephalus requiring a cerebrospinal fluid diversion procedure. The present study aims to assess the effectiveness of endoscopic biopsy and third ventriculostomy (ETV) in these patients.

MATERIALS AND METHODS

Twenty-four patients with PTV lesions with moderate to severe hydrocephalus were managed prospectively. All patients underwent ETV and biopsy of the lesion during the same procedure. The ETV could be performed in all patients, where as in 23, a successful biopsy could be obtained. The ETV was successful in 22 patients; it failed in 2 patients requiring shunt insertion. A positive biopsy was obtained in all the patients (pinealocytoma 4, pinealoblastoma 10, embryonal cell carcinoma 1, germinoma 2, oligodendroglioma 1, astrocytoma 2, tuberculoma 4). All patients were subsequently managed with further surgery, radiation, and chemotherapy either alone or in combination depending on the pathology. One patient with a tumor bed hematoma required clot evacuation. The follow-up period ranged from 12 to 36 months. Two patients died, one during hospital stay with a tumor bed hematoma and another at 6 months follow-up due to extensive leptomeningeal spread.

CONCLUSIONS

The high yield of endoscopic biopsy (100%) and success of ETV (91%) emphasizes its role in management of the diverse group of PTV lesions in arriving at the optimal definitive management.

Management of pineal region tumors

Tumors of the pineal region represent a diverse collection of tumors with a variety of natural histories. This diversity necessitates accurate histologic diagnosis to allow rational therapeutic planning. Evaluation of a pineal lesion should begin with craniospinal MRI and analysis of the cerebrospinal fluid (CSF). Whereas certainty of the histologic diagnosis is now a requirement for treatment in Western nations, some Asian centers continue to recommend a test dose of radiation therapy based on the high incidence of germinoma in those countries. If there is high clinical suspicion of a germinoma or tectal glioma, stereotactic or endoscopic biopsy may be pursued. All other lesions should be referred for open biopsy with microsurgical techniques. This approach provides adequate tissue for diagnosis, may be curative in low-grade tumors, and may substantially improve survival in patients with malignant tumors. If open surgery is not desired by the patient or practitioner, stereotactic or endoscopic biopsy may be followed by radiosurgery for localized, well-demarcated tumors. Radiation therapy is the first-line therapy for germinomas. Although the optimal radiation dosage and volume have not been decided, the current Children's Oncology Group trial may offer definitive evidence to address this dilemma in germ cell tumors. Evidence of CSF seeding requires craniospinal radiation and adjuvant chemotherapy regardless of tumor type. Diagnosis of any of the malignant tumors (non-germ cell tumors, pineoblastomas, and parenchymal tumors of intermediate determination) also requires craniospinal radiation (with local tumor doses of at least 50 Gy) and adjuvant chemotherapy (generally platinum based). Patients with tectal gliomas may undergo excision with or without postoperative radiation; however, they also may be observed with vigilant follow-up alone.

Outcomes in patients undergoing single-trajectory endoscopic third ventriculostomy and endoscopic biopsy for midline tumors presenting with obstructive hydrocephalus

OBJECT

The primary aim of this study was to evaluate the success of endoscopic third ventriculostomy (ETV) as a treatment for obstructive hydrocephalus secondary to midline tumors (midbrain, pontine, pineal, tectal plate, thalamic, and third ventricular regions). In addition, the study examined the role and value of endoscopic tumor biopsy (ETB) in the management of such cases. All surgical procedures were performed through a single-trajectory approach.

METHODS

A retrospective analysis of clinical notes, operation records, and pre- and postventriculostomy neuroimaging data was performed to determine the success or failure and complications of ETV and ETB in 42 patients presenting with tumor-induced obstructive hydrocephalus. Patient data were derived from an endoscopy database initiated in 1998. The study population included 21 female and 21 male patients (mean age 37 years, range 5-77 years). All 42 patients underwent an ETV; 33 of the 42 underwent an ETV and an ETB (single-trajectory). One patient was excluded from the follow-up analysis due to rapid deterioration of his condition from tumor progression. The duration of follow up ranged from 3 to 84 months (mean 32 months). At the last follow up, 11 patients with ETVs had undergone shunt placement and two patients had undergone repeated ETVs, giving a long-term success rate of 68% (28 of 41 cases) for single ETV as a treatment for hydrocephalus at presentation. Statistical analysis revealed no significant relationship (p > 0.92) between tumor location and ETV success or failure. The mean time to ETV failure was 32 weeks. Histological examination of biopsy specimens was non-diagnostic in eight (24%) of the 33 cases in which ETB was performed. Seven of these cases involved pineal region tumors and one involved a tectal plate tumor. There was no death or major morbidity associated with ETV and ETB in this series.

CONCLUSIONS

Endoscopic third ventriculostomy is a safe and durable means of controlling hydrocephalus in tumor cases. Its success rate is high--comparable to that reported in aqueduct stenosis cases. Although ETB is probably not as accurate for diagnosis as biopsy with frame-based stereotactic guidance, it is associated with a lower mortality rate and, in the correct clinical setting, may be justifiably attempted as an initial biopsy procedure at the same time as ETV via a single-trajectory approach.

Neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle: indications, technique, complications, and results

OBJECTIVE

Evaluation of results of the neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle.

METHODS

From 2001 to 2004, 23 patients (mean age, 30.6 yr) with tumors located in the pineal region or posterior third ventricle underwent neurofiberscopic biopsy with simultaneous third ventriculostomy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by radiotherapy and/or chemotherapy without open surgery (eight patients), establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy (11 patients), differentiation of the recurrent neoplasm and radiation necrosis (two patients), and decompression of the large tumor-associated cyst (two patients). In six previously shunted patients, substitution of the ventriculoperitoneal shunt on the third ventricle stoma was performed.

RESULTS

There was no postoperative mortality or permanent morbidity. In all cases, the obtained tissue sample was sufficient for pathological diagnosis. Transient postoperative complications included fever (15 patients), nausea and vomiting (three patients), and diplopia (one patient). On the long-term follow-up, delayed third ventricular stoma failure caused by tumor regrowth and scar formation was found in one patient, and dissemination of the malignant glioma through the subarachnoid space was found in another patient.

CONCLUSION

Neurofiberscopic biopsy represents a useful method for sampling of tumors of the pineal region and posterior third ventricle, which can be effectively used in both previously shunted and shunt-free patients.

Validation of intraoperative diagnoses using smear preparations from stereotactic brain biopsies: intraoperative versus final diagnosis--influence of clinical factors

OBJECTIVE

Despite improvements in imaging techniques, histopathological diagnosis is still an important tool in neuro-oncology. At Freiburg University Hospital in Germany, approximately 450 patients per year undergo a serial stereotactic biopsy to obtain a diagnosis. We analyzed the accuracy of intraoperative diagnosis for rapid establishment of treatment options. Furthermore, we wanted to find out whether the location and histopathology of the tumors as well as the age and sex of the patients affected accuracy. Because of the large number of biopsies performed per year, parameters could also be evaluated for rare cerebral lesions.

METHODS

We retrospectively analyzed 5000 consecutive stereotactic brain biopsies from 4589 patients. The digital database comprises the intraoperative and final diagnoses, the location of the tumors, and the sex and age of the patients. Regression analysis was performed to identify parameters that had a significant impact on the results.

RESULTS

Intraoperative diagnosis was correct in 90.3% of biopsies. This included complete correlation in 81.3% of the biopsies and partial correlation in 9% of the biopsies. In 5.1% of the biopsies, no correlation between the intraoperative and final diagnosis was obtained. In 4.6% of the biopsies, no diagnosis could be made during or after surgery. A high correlation was found for World Health Organization Type II astrocytomas and, with regression analysis, for World Health Organization Type I astrocytomas, glioblastomas, and metastases.

CONCLUSION

Intraoperative diagnosis with stereotactic biopsy has high validity. Immediate treatment based on the intraoperative diagnosis can be justified (e.g., for metastases or glioblastomas). Stereotactic biopsy with an exact histopathological diagnosis is strongly recommended for planning adequate therapy for patients with unidentified brain lesions.

Pineal parenchymal tumors of intermediate differentiation in adults: Case report and literature review

Pineal parenchymal tumors (PPT), including pineoblastomas, are very uncommon, especially in adults. Because of the small number of reported cases, the histological and biological features of these tumors are still being defined, as is their optimal management. Also, the pathological variability of these tumors makes it difficult to draw general conclusions about their behavior. We report the case of a PPT of intermediate differentiation (PPTID) with an excellent outcome. A 3.2 cm tumor in the pineal and tectal region with obstructive hydrocephalus was found in a 28-year-old female complaining of headaches and hypoesthesia of the right side of the face. Stereotactic biopsy revealed a highly cellular tumor composed of small cells that contained little cytoplasm that were arranged in a diffuse pattern. Mitotic activity was low and there was no evidence of necrosis. Immunohistochemical examination demonstrated positive staining for neuron-specific enolase and synaptophysin. There was no expression of neurofilaments or GFAP. Ki-67 proliferation index was 12%. The diagnosis was a PPTID. Treatment consisted of combined neoadjuvant chemotherapy and craniospinal radiotherapy. Six years after treatment, the patient is alive and free of any clinical or radiological signs of relapse. This paper discusses the pathological and biological features of these tumors and the treatment options available.

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours

OBJECT

The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT).

POPULATION AND METHODS

We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy).

RESULTS

With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery.

CONCLUSION

This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

Isolated pineal region metastasis of small cell lung cancer

The pineal region is an unusual site for brain metastasis and most metastatic pineal lesions are asymptomatic. Rarely the symptoms of metastatic involvement of the pineal gland precede those of the primary tumor or other metastatic sites. An 83 year-old man presented with gait disturbance and limitation of upward gaze. Brain MRI showed homogeneous enhancement of a solitary mass in the pineal region with obstructive hydrocephalus. A stereotactic biopsy was performed, and small cell carcinoma was diagnosed. A systemic investigation for the primary lesion subsequently revealed small cell carcinoma of the lung. The patient was referred for radiotherapy and chemotherapy. Although rare, metastatic tumor should be considered in the differential diagnosis of pineal region tumors, particularly in elderly patients.