Colloid cysts of the third ventricle: ultrastructural features are compatible with endodermal derivation

Endoscopic trans-septal interforniceal approach for excision of colloid cysts of the third ventricle using the rotational technique

Colloid cysts of the third ventricle are benign intracranial lesions that account for 0.5 to 2% of all brain tumors and are even rarer in pediatric population. Dandy was the first to successfully excise a colloid cyst of the third ventricle via a transcortical transventricular approach in 1921. For several decades to follow, the transcortical transventricular and transcallosal microsurgical approaches remained the cornerstone of surgical management of these lesions. With time and refinements in endoscopic equipment and techniques, endoscopic resection of colloid cysts evolved into a currently well-established and appealing minimally invasive alternative to microsurgery. Endoscopic endochannel techniques for colloid cysts of the third ventricle may either be transforaminal or trans-septal interforniceal, depending on the pathoanatomical features of the colloid cyst and its relation to the juxtaposed anatomical structures. The endoscopic trans-septal interforniceal approach is required to access the rare subset of colloid cysts that extend superior to the roof of the third ventricle between the two fornices insinuating themselves between the leaflets of the septum pellucidum. In this article, the surgical technique of the endochannel endoscopic trans-septal interforniceal approach is elaborated upon. A representative case is presented along with an operative video.

Rate of Missed Intracranial Colloid Cysts on MRI and CT

BACKGROUND AND PURPOSE

Intracranial colloid cysts of the third ventricle are rare; however, they may be symptomatic. They can create a mass effect on the foramina of Monro, resulting in acute hydrocephalus. Colloid cysts are detectable on CT and MRI but are commonly missed. In this paper, we investigate the rate of missed colloid cysts on MRI and/or CT imaging within our multihospital metropolitan medical group.

MATERIALS AND METHODS

A retrospective, institutional review board-approved search of the network-wide picture archiving and communication system (PACS) from January 1, 2010, to October 31, 2020, was performed to identify reports including a "colloid cyst" in MRI brain or CT head imaging. Results without imaging and/or surgical confirmation of intracranial colloid cysts were excluded, rendering 229 cases. A PACS review of these cases was performed by two neuroradiologists to determine instances where the cyst had previously been imaged but not diagnosed on either CT or MRI.

RESULTS

Two hundred twenty-nine subjects had confirmed colloid cysts through imaging and/or surgical reports. Of these, 46 had prior imaging depicting a colloid cyst either on CT and/or MRI without mention on the interpretative report, resulting in a non-detection rate of 20.1%.

CONCLUSION

Intracranial colloid cysts can be missed at a considerably high rate, which is concerning given their clinically unpredictable nature and ability to cause significant morbidity and mortality. As such, it is important to take a proactive approach to searching for these cysts as part of a regular imaging search pattern and to continue to determine new methods of increasing detection sensitivity.

Intraventricular sizeable colloid cyst with atypical radiological features: A case report and evidence-based review

Colloid cysts are benign intracranial lesions, typically located in the anterior portion of the third ventricle near the interventricular foramina of Monro. The cysts usually consist of an epithelial lining filled with viscous gelatinous material of various components. Colloid cysts are generally asymptomatic, but once symptomatic, they can present in a variety of ways, including headaches, vomiting, visual and memory problems, and vertigo. Colloid cysts present classically on imaging as a well-delineated hyperattenuating lesion on unenhanced radiological modalities. Herein, we report a case of a patient who presented with hydrocephalus caused by a sizeable colloid cyst which demonstrated atypical imaging findings in the form of hypodensity on CT and hyperintensity on T2WI, making them difficult to identify and easy to miss. Although this atypical imaging appearance is uncommon with yet unknown true incidence, it is prudent to be aware of it because early management of colloid cysts has a favorable outcome, in contrast to untreated cysts that are associated with higher rates of morbidity and mortality. Additionally, we provide a comprehensive, evidence-based review of the medical entity of intracranial colloid cysts with highlights of current postulated pathological theories and management algorithms.

First reported case of hydrocephalus in jointly diagnosed bacterial meningitis and a colloid cyst: how Ockham's razor became Hickam's dictum

We report the first case in the literature of acute hydrocephalus due to a simultaneous diagnosis of bacterial (not asceptic) meningitis and a colloid cyst. Diagnosing disease is the cornerstone skill of a medical practitioner. Both education and experience allow for sharpening of this skill throughout years of medical practice. Disease is fraught with nuances and inconsistencies which can render an accurate diagnosis a difficult task. Medical practitioners can be guilty of cognitive biases such as Ockham's razor. We present the case of a patient with an initial diagnosis of obstructive hydrocephalus secondary to a colloid cyst. However, pneumococcal meningitis blunted Ockham's razor in favour of Hickam's dictum.

Retrospective evaluation of endoscopic treatment in colloid cyst of the third ventricle

Introduction

Endoscopic methods have gained a well-established position in surgical treatment of colloid cysts of third ventricle. However, the possibility of total tumor removal with this method and the long-term effectiveness of treatment are being questioned.

Aim

Personal twenty years’ experience in treatment of third ventricle colloid cysts is presented on the basis of retrospective analysis.

Material and methods

The study group included 58 patients diagnosed by neuroimaging (head CT/MRI) with third ventricle colloid cyst. Post-hospital follow-up ranged from 18 to 42 months. Long-term follow-up head CT/MRI was performed in 39 patients.

Results

The colloid cyst was removed totally in 47 (81%) patients. In 11 cases, the colloid cyst’s wall was tightly adherent to the roof of the third ventricle, which limited the radicality of the procedure. Sixteen patients demonstrated memory impairments, 4 patients epilepsy and another 2 akinetic mutism in the direct postoperative course. One patient died as a result of complications unrelated to the procedure. The average hospitalization was 5 days. In the late period after surgery, remission of the most, previously, reported ailments and symptoms has been reported. Surgical treatment for hydrocephalus was needed in 7 patients. In 3 cases cyst recurrence was diagnosed which required reoperation.

Conclusions

The endoscopic methods allow the total removal of a third ventricle colloid cyst in most patients. Leaving a small coagulated fragment of the cyst rarely results in its recurrence. This method results in effective treatment with a low complications rate, shortens hospitalization time and brings the patient a high level of satisfaction with a quick recovery.

Management of pineal and colloid cysts

The widespread use of MRI has led to the increasingly frequent diagnosis of pineal and colloid cysts. While most are small and incidental, do not require long-term monitoring and will never need treatment, they are a cause of patient anxiety and clinician uncertainty regarding the optimal management-particularly for larger cysts or those with an atypical appearance. Occasionally pineal cysts, and more commonly colloid cysts, cause hydrocephalus that requires urgent neurosurgical treatment. More recently the non-hydrocephalic symptomatic pineal cyst has been described in the neurosurgical literature but there is controversy over this entity and its management. This review addresses the difficulties in managing pineal and colloid cysts and provides a pragmatic framework for the practising clinician.

Risk Analysis and Management of Third Ventricular Colloid Cysts

OBJECTIVE

Colloid cysts (CCs) are histologically benign lesions that carry the risk of causing obstructive hydrocephalus. The indication for surgery for symptomatic cysts is unquestioned; however, the management of incidentally detected lesions has remained controversial. We independently evaluated the CC risk score (CCRS) as a useful risk stratification scheme.

METHODS

The demographics, imaging characteristics, and clinical presentations of 103 patients with CC during a 10-year period were correlated with symptoms and the occurrence of hydrocephalus. The discriminate capacity of the CCRS was quantified and a decision algorithm formulated.

RESULTS

The correlates of symptoms included age <65 years, diameter ≥7 mm, anterior location, hyperintensity on T2-weighted fluid-attenuated inversion recovery (FLAIR) and/or T2-weighted images, and headache at presentation without an alternative explanation. On multivariate analysis, age <65 years, diameter ≥7 mm, and headache at presentation predicted for symptomatic cysts. The CCRS was highly effective at identifying symptomatic patients and those with obstructive hydrocephalus. All patients with cyst growth and symptomatic progression had had an initial CCRS of ≥3 plus hyperintensity (preexisting or developing) on T2-weighted FLAIR images.

CONCLUSIONS

The CCRS performed exceptionally well in distinguishing the highest risk patients. Closer follow-up is recommended for younger asymptomatic patients with cysts near the foramen of Monro. Hyperintensity on T2-weighted FLAIR images might indicate greater growth potential for small lesions.

The Variable Appearance of Third Ventricular Colloid Cysts: Correlation with Histopathology and the Risk of Obstructive Ventriculomegaly

BACKGROUND AND PURPOSE

While third ventricular colloid cysts may present as an incidental finding, they also harbor the potential to cause ventricular obstruction and sudden death. Herein we analyze the relationship between imaging appearance and the risk of obstructive ventriculomegaly.

MATERIALS AND METHODS

This is a retrospective review of the MR imaging appearance of 64 patients with colloid cysts, 46 of whom also had a CT scan, obtained by a tertiary hospital imaging report data base search over a 10-year period. Cysts were categorized by appearance on T2-FLAIR and correlated with patient age, cyst size, and the risk of obstructive ventriculomegaly. Histopathologic correlation was available for 28 cases.

RESULTS

The 64-patient cohort was 52% female, median age 50 years (range 10 to 99 years). Cysts hyperintense on T2-FLAIR (53.1%) were larger (P <.001), occurred in younger patients (P = .01), and had a higher risk of obstructive ventriculomegaly than homogeneously hypointense cysts (relative risk 6.18, 95% CI [2.04, 18.67]). Three patterns of T2 hyperintensity were identified: homogeneously hyperintense, hyperintense rim, and cysts with "dot sign." Although "dot sign" cysts were larger (P < .001), there was no significant difference in patient age or the risk of ventricular obstruction among T2 hyperintense cysts. Cyst wall histopathology did not vary with imaging appearance.

CONCLUSIONS

Hyperintensity on T2-FLAIR, whether homogeneous, rim, or "dot sign," is associated with larger cyst size and younger patient age, and is an imaging risk factor for obstructive ventriculomegaly. The hyperintense rim does not represent a thickened cyst wall.

Genetics of Colloid Cyst in Monozygotic Twins: Case Report and Review of Literature

BACKGROUND

Colloid cysts are rare developmental lesions, accounting for approximately 1% of intracranial tumors. Often, these benign lesions are asymptomatic, but they are associated with significant mortality as a result of acute hydrocephalus. This mortality in patients with vague or no symptoms dictates a need for better understanding of the etiology of colloid cysts to expedite diagnosis and management. We present a case of monozygotic twins with colloid cysts to propose a genetic etiology for colloid cyst.

CASE DESCRIPTION

Previously healthy male monozygotic twins presented 4 years apart with headache secondary to hydrocephalus as a result of colloid cysts. Both patients underwent multiple surgeries and were doing well at last follow-up.

CONCLUSIONS

The present case adds to a body of literature of familial colloid cysts, suggesting higher concordance in monozygotic compared with dizygotic twins. This may be due to high genetic load, shared intrauterine environment, epigenetic changes, or genetic mutation. This literature review suggests that given high morbidity and mortality of colloid cysts, screening may be beneficial. Even in the absence of a single, definitive genetic etiology, we recommend consideration of genetic screening or, at a minimum, screening with neuroimaging for monozygotic twins in cases where 1 twin is diagnosed with colloid cyst.

The Case of the Disappearing Colloid Cyst

BACKGROUND

The natural history of colloid cysts is imperfectly understood, and controversies remain in defining broad management strategies for incidental colloid cysts. The gradual asymptomatic regression of a colloid cyst has not been reported.

CASE DESCRIPTION

We present a unique case demonstrating the clinically silent, gradual regression of a colloid cyst over many years.

CONCLUSIONS

Gradual regression of a colloid cyst is possible. The philosophical and practical implications of this case on the neurosurgeon's approach to managing patients with colloid cysts are discussed.

A unique finding of cavum velum interpositum colloid-like cyst and literature review of a commonplace lesion in an uncommon place

Colloid cysts typically reside within the area of the anterior third ventricle, in the proximity of the foramen of Monro. Although they are considered to commonly localize in various parts of the cerebrum, they are exceedingly rare outside the ventricular system and rarely occur within the velum interpositum. We have reported here a rare case of a velum interpositum colloid-like cyst in a 23-year-old man, who presented to our clinic with temporary binocular strabismus, which he had been experiencing for the previous year. In addition, we have briefly reviewed evidence regarding the generation, anatomy, and pathogenesis of colloid cysts, as well as the management options for such rare cases. The present report is only the third to describe a colloid-like cyst located within the velum interpositum, providing additional data that may aid in elucidating the pathogenesis of these neoplasms.

Microsurgical Treatment of Colloid Cysts of the Third Ventricle

BACKGROUND

This study analyzes the results of surgical treatment in 377 patients with colloid cysts (CCs) of the third ventricle who were treated at the Burdenko Neurosurgery Institute from 1981 to 2015. Operations were performed by a single surgeon (the first author of the article).

METHODS

The transcallosal approach was used to remove CCs in 97% of cases. Total cyst removal was performed in 96% of cases (in 4% of cases, a small cyst capsule fragment was left on the veins and fornix); in 3 cases, the cyst recurred, which required its repeated removal.

RESULTS

Hydrocephalus symptoms regressed in 98% of patients. The most frequent complications in the early postoperative period were memory impairments of varying severity, with a tendency to regress by the time of discharge. Two patients had an intraventricular hematoma, which required operative exploration in 1 patient. There were 4 cases of meningitis (including 1 shunt-associated meningitis) and 5 cases of transient pyramidal insufficiency.

CONCLUSIONS

We made a preliminary assessment of the reasonability of the infratentorial supracerebellar approach for removal of CCs in 10 cases.

TWO UNCOMMON CASES OF COLLOID CYST OF THE THIRD VENTRICLE

Colloid cysts of the third ventricle of brain comprise 1-2% of all intracranial tumonrs [1]. They are increasingly being discovered incidentally, often in patients complaining of headache [2]. We came across two such cases in a large tertiary care service hospital in the past 20 years. Second case also had associated visual disturbances and seizures. Both met with fatal outcome. Autopsy revealed presence of colloid cyst in the third ventricle in both cases. It is proposed that to avoid fatal outcome in a patient reporting with frequent attacks of headache, the presence of colloid cyst in the third ventricle should be considered in differential diagnosis. In such cases, CT scan or MRI study of brain becomes an essential diagnostic tool.

Microsurgical vs. Endoscopic Excision of Colloid Cysts: An Analysis of Complications and Costs Using a Longitudinal Administrative Database

OBJECTIVE

Open microsurgical and endoscopic approaches are the two main surgical options for excision of colloid cysts. Controversy remains as to which is superior. Previous studies consist of small cohort sizes. This topic has not been investigated using national administrative claims data which benefits from larger patient numbers.

METHODS

Current Procedural Terminology (CPT) and International Classification of Disease version 9 (ICD-9) coding at inpatient visit was used to select for index surgical procedures corresponding to microsurgical or endoscopic excision of colloid cysts. Comorbidities, costs, and complications were collected.

RESULTS

We identified a total of 483 patients. In all, 240 were from the microsurgical cohort and 243 were from the endoscopic cohort. The two groups displayed similar demographic and comorbidity profiles. Thirty-day post-operative complications were also similar between groups with the exception of seizures and thirty-day readmissions, both higher in the open surgical cohort. The seizure rates were 14.7 and 5.4% in the microsurgical and endoscopic cohorts, respectively (p = 0.0011). The thirty-day readmission rates were 17.3 and 9.6% in the microsurgical and endoscopic cohorts, respectively (p = 0.0149). Index admission costs and 90-day post discharge payments were higher in patients receiving microsurgical excision.

CONCLUSION

An analysis of administrative claims data revealed few differences in surgical complications following colloid cyst excision via microsurgical and endoscopic approaches. Post-operative seizures and thirty-day readmissions were seen at higher frequency in patients who underwent microsurgical resection. Despite similar complication profiles, patients undergoing microsurgical excision experienced higher index admission costs and 90-day aggregated costs suggesting that complications may have been more severe in this group.

Spontaneous resolution of colloid cyst of the third ventricle: Implications for management

While there is little controversy regarding the treatment of symptomatic colloid cysts, the optimal management of “incidentally” detected and asymptomatic colloid cyst remains unclear. The age of the patient, duration and significance of symptoms related to the cyst, size and radiological characteristics of the cyst and the presence of hydrocephalus are all factors to be considered before considering surgery. While surgery most often provides good results in the majority of patients, complications do occur. Despite growing literature about the natural history of this condition, to date, only three cases of spontaneous resolution of colloid cyst <10 mm have been reported. We report the case of spontaneous resolution of a colloid cyst larger than 10 mm, initially managed with close observation and serial neuroimaging. This case highlights the possible role for a conservative approach even in larger-sized cysts.

Paired Colloid Cysts in the Third Ventricle

BACKGROUND

Colloid cyst is the most common neoplastic lesion of the third ventricle, and the occurrence of 2 colloid cysts in the ventricular system is rare.

CASE REPORT

We present a 35 year old female patient with paired colloid cysts of the third ventricle who presented with obstructive hydrocephalus and were treated surgically with the transcallosal interhemispheric transforaminal approach. Until now only 3 patients of dual or paired colloid cysts of different ventricles were reported. To the best of our knowledge, this is the first case with both the colloid cysts present in the third ventricle.

CONCLUSION

This report illustrates the importance of proper radiologic study in a case of colloid cyst and preparing preoperatively and excision of both the colloid cyst whenever present, ​to prevent the recurrence.

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.

MRI features have a role in pre-surgical planning of colloid cyst removal

BACKGROUND

Endoscopic resection is becoming a well-established treatment option for patients with colloid cysts of the third ventricle. A disadvantage of this approach is the decreased ability to resect cysts in their entirety. Correlations between magnetic resonance imaging (MRI) features and cyst content could potentially help surgeons decide on the extent of resection and approach. We attempted to identify a correlation between patients' MRI imaging patterns and difficult cyst removal, post-operative adverse outcomes and the need for cerebrospinal fluid (CSF) diversion, in order to detect markers that may affect pre-surgical planning.

METHOD

A retrospective examination of all patients' records that underwent a colloid cyst excision attempt at our institution between 2001 and 2014, and which had a minimum 1-year follow-up was compiled.

RESULTS

Of the 25 patients fulfilling the criteria, we found cysts with a low T2 signal, specifically when combined with high T1 signal, to be significantly correlated with piecemeal, difficult removals. Correlation was also found between high T2 signal cysts and pre-operative hydrocephalus. Among patients that had pre-existing hydrocephalus, those that required a piecemeal removal possessed a strong trend towards a need for subsequent shunting.

CONCLUSIONS

We found specific MRI features suggestive of difficult cyst excision. In a subgroup of patients with pre-operative hydrocephalus and imaging features suggestive of difficult removal, significantly higher rates of shunting were observed. We therefore recommend an open approach in cases of low T2, high T1 signal cysts with a diameter of over 15 mm, or CSF shunting in poor surgical candidates. Smaller cysts, with a low T1 signal, a high T2 signal and pre-operative hydrocephalus, constitute a subgroup in which we recommend endoscopic intervention as the procedure of choice.

Huge familial colloid cyst of the third ventricle: An extraordinary presentation

Background:

Since the use of computed tomography and magnetic resonance imaging, colloid cysts (CCs) are discovered more frequently and subsequently their true incidence exceeds the numbers previously estimated. In 1986, the first familial case was reported in two identical twin brothers. To date, a total of 17 of these cases have been reported, all differing in the pattern of affected family members.

Case Description:

Here, we describe a unique presentation of a familial case and review the relevant literature on CCs and their natural history to improve our understanding of these cases.

Conclusion:

Familial CC can present in various patterns, sizes, and forms. A genetic factor is likely to be responsible in these cases, and further research is warranted to clarify this phenomenon.

Suprasellar dermoid cyst associated with colloid cyst of the third ventricle: Disordered embryogenesis or a mere coincidence?

Intracranial dermoid cyst and colloid cysts of the third ventricle are rare benign congenital lesions of early adulthood. Both lesions are thought to be congenital in origin however association is rare. Only one case of this association has been reported. We report a 22-year-old male with suprasellar dermoid cyst and colloid cyst of the third ventricle presenting simultaneously. Embryogenesis of this association has been discussed.

Full scope of options

OBJECTIVE

The purpose of Clinical Problem Solving articles is to present management challenges to give practicing neurosurgeons insight into how field leaders address these dilemmas. This illustration is accompanied by a brief review of the literature on the topic.

PRESENTATION

The case of a 16-year-old boy presenting with headaches is presented. The patient is found to have a typical colloid cyst at the foramen of Monro. Bilateral ventriculoperitoneal shunt placement had been performed as an initial treatment of the patient before presentation.

RESULTS

Surgeons experienced in open and endoscopic surgery discuss their individual approaches to colloid cysts, in the context of previous shunting, providing a varied perspective on the clinical challenges posed by these lesions.

CONCLUSION

Both open and endoscopic options remain viable for excision of a colloid cyst. Each has associated potential complications, as illustrated by the current case.

Pediatric colloid cysts of the third ventricle: management considerations

PURPOSE

Pediatric colloid cysts (CC) have a congenital origin, and yet, there are very few studies focussing exclusively on their occurrence in the pediatric population. Pediatric CC has been associated with more aggressive clinical and radiological patterns than their adult counterparts. In this study, undertaken on children with anterior third ventricular CC, excised using the interhemispheric transcallosal approach, the characteristic clinicoradiological features and management options are studied.

METHODS

Five pediatric patients (aged 16 years or less; mean age 13.8 years; mean duration of symptoms:7.6 months) out of 38 patients with CC operated between 1995 to 2009 were included. The clinical manifestations included those of raised intracranial pressure (n = 4); exacerbation of occipital headache on reading (n = 1); secondary optic atrophy (n = 3); and, drop attacks (n = 1). On computed tomography scan, the cyst was hyperdense, enhancing in two patients and not enhancing in three patients. All had bilateral lateral ventricular dilatation with periventricular lucency. On magnetic resonance imaging (n = 3), the cyst was T1 hypointense and T2 isointense in one, hyperintense on both T1 and T2 with a hypointense capsule and nonenhancing on contrast in one (with a giant colloid cyst), and T1 hyperintense and T2 hypointense in one patient. An interhemispheric, transcallosal trajectory combined with transforminal approach (n = 3); combined transforminal and subchoroidal approaches (n = 1); and, interforniceal approach (n = 1) were used.

RESULTS

Total excision was performed in four patients. In one patient, a small part of capsule was left attached to thalamostriate vein. Symptoms of raised intracranial pressure showed improvement in all the patients with resolution of hydrocephalus. There was no tumor recurrence at follow-up.

CONCLUSIONS

Pediatric colloid cysts are rarer than their adult counterparts due to their late detection only after manifestations of raised intracranial pressure, visual or cognitive dysfunction or drop attacks occur. Their radiological appearance varies depending upon the amount of mucoid content, cholesterol, proteins, and water content. The fast development of clinical manifestations in children may be related to rapid enlargement of cyst due to higher water content within them. The transcallosal approach is the "gold standard" of surgery and usually ensures gratifying and lasting results.

Obstructive hydrocephalus due to a third ventricular neuroepithelial cyst

Cysts occupying the third ventricle are rare lesions and may appear as an unusual cause of obstructive hydrocephalus. Various types of lesions occur in this location, and they generally have an arachnoidal, endodermal, or neuroepithelial origin. The authors present a case of acute hydrocephalus following minor trauma in a child due to cerebrospinal fluid outflow obstruction by a third ventricular cyst. Definitive diagnosis of this cystic lesion was possible only with contrast ventriculography and not routine computed tomography or magnetic resonance imaging. The investigation, treatment, and pathological findings are discussed.

Choroid plexus acinar adenoma: a case report

Mucus-secreting adenomas or acinar adenoma of the choroid plexus are very rare. We report the case of a 79-year-old male with a 3-year history of occipital headaches with vomiting, ataxia and cerebellar signs. He was first seen due to difficulty while walking. He was admitted to the hospital with significant tumor expansion and clinical deterioration. CT and MRI revealed obstructive hydrocephalus secondary to a large fourth ventricular cyst mass, which enhanced markedly on contrast administration. Pathological findings were consistent with an acinar choroid plexus adenoma. The tumor was attached to the ependymal lining and was strongly adhered to the walls and floor of the IV ventricle. Post-operative bleeding complicated partial removal of this tumor. The patient died 6 h after surgery.

Coexistence of colloid cyst and neuroglial heterotopia

INTRODUCTION

Colloid cyst is a rare intracranial tumor in childhood. This is the first report on the coexistence of a colloid cyst and the neuroglial heterotopia.

DISCUSSION

A 3-year-old boy presented with a 10-day history of headache. Radiological findings revealed a cyst in the third ventricle and a solid mass protruding into the lateral ventricle causing obstructive hydrocephalus. The cyst was attached to the solid mass. Endoscopic aspiration and removal of the cyst followed by biopsy of the protruding mass was performed. Headache and vomiting then disappeared and the patient returned to normal life.

CONCLUSION

The pathologic diagnosis was a colloid cyst associated with neuroglial heterotopia. We experienced a case of coexistent colloid cyst and neuroglial heterotopia, which have different embryonal origins.

The role of electron microscopy in the diagnosis of surgical pathology in the central nervous system

Electron microscopy has played an important role in the diagnosis of surgical pathology and the establishment of new tumor entities and variants in the central nervous system. However, the use of ultrastructural analysis of brain tumors has decreased with the advent of immunohistochemistry. I present here my personal experiences and perspective on the role of electron microscopy in surgical neuropathology.

Neuroenteric cyst of the anterior cranial fossa: case report and review of the literature

A case of intradural neuroenteric cyst located in the anterior cranial fossa is presented. The cyst caused anosmia and progressive personality changes in an elderly woman. The patient underwent bifrontal craniotomy with evacuation of cyst contents and removal of the cyst wall. Incidence, classification, histopathology, and histogenesis of neuroenteric cysts are discussed with review of the literature.

Third ventricular colloid cysts in children

INTRODUCTION

Colloid cysts of the 3rd ventricle are relatively rare intracranial tumours, more so in children. They are benign tumours with excellent prognosis if diagnosed and treated early.

METHODS

A retrospective analysis of 18 cases of colloid cysts in children below 18 years, operated in our institution between September 1998 and November 2003 (5 years) was made. Clinical presentation, radiological findings, surgical approaches and outcome were analysed.

RESULTS

Age ranged from 7 to 18 years. The male-to-female ratio was 12:6. Headache and vomiting were the most common symptoms. Papilloedema was the most common clinical sign. Pre-operative CT showed a hyperdense non-enhancing lesion in the majority. Twelve patients underwent a transcallosal, 2 a transcortical and 4 an endoscopic approach. Ventriculoperitoneal shunts were done in 5 patients. Postoperatively 2 patients developed epidural haemorrhage which required evacuation. One patient was re-explored for symptomatic residue. A mean follow-up of 10.2 months was available in 9 patients; the majority were asymptomatic.

CONCLUSION

Colloid cysts though rare are increasingly detected in children. Their early recognition and treatment give excellent results.

Colloid (Enterogenous) Cyst in the Frontal Lobe-Case Report-

A 60-year-old man presented with a left frontal mass lesion incidentally detected at a health check without apparent symptoms. Computed tomography revealed the lesion as homogeneous high density and magnetic resonance (MR) imaging showed the lesion as hyperintense on T(1)-weighted images, isointense on T(2)-weighted images, and hypointense on diffusion-weighted images. T(1)-weighted MR images with gadolinium showed no enhancement of the mass lesion. Cerebral angiography revealed an avascular area around the left frontal lesion. Total removal of the lesion was achieved through a craniotomy without complications. Histological, immunohistochemical, and electron microscopy examinations established the definite diagnosis of colloid cyst.

Benign cysts in the central nervous system: Neuropathological observations of the cyst walls

A diverse variety of benign cysts exist in the CNS. Advances in diagnostic radiology have facilitated diagnoses and surgical intervention in many patients with CNS cysts. However, a fundamental understanding of the pathological features of these lesions is clinically vital. From an etiological point of view, the cysts can be divided into two groups. The first includes lesions that arise from within the CNS and may be static structures such as cavities arising from infarcts and other destructive processes while other lesions such as arachnoid cysts, ependymal cysts, cystic hemangioblastoma, cystic cerebellar astrocytoma and infectious processes, are progressive. The second group of cysts arise from the intrusion of non-nervous system tissue into the neuroaxis and are usually midline. They are frequently expanding congenital lesions although some become symptomatic only in adults. Examples include teratomas, dermoid cysts, epidermoid cysts, craniopharyngiomas, Rathke's cleft cysts, and other epithelial cysts presumably derived from the upper respiratory or intestinal tract. Chick embryos exposed to lead have been used as a model of cyst formation.

Intraepithelial carcinoma arising in an endodermal cyst of the posterior fossa

Endodermal cysts of the central neuraxis are benign, non-neoplastic epithelium-lined cysts arising from endodermal tissue that have been displaced early in fetal life. Intracranial endodermal cysts are rare and usually located in the posterior fossa. The present study involves a 36-year-old man with a typical epithelial cyst in the posterior fossa. Microscopically, the cyst has a simple columnar epithelium with mucus-producing cells, containing an area composed of dysplastic epithelium with evidence of an intraepithelial carcinoma. The atypical cells have a high proliferative fraction demonstrated by Ki-67 immunostain. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic endodermal cyst. The clinicopathologic features and a review of the literature are discussed.

Cyst of the third ventricle as an unusual cause of acquired hydrocephalus

Cysts of the third ventricle are rare congenital suprasellar malformations of arachnoidal, endodermal, or neuroepithelial origin. Depending on their size and location, they can cause space-occupying intracranial lesions and hydrocephalus occlusus by obstruction of the aqueduct or foramen of Monro. They can be missed on routine computer tomography and magnetic resonance imaging. A 2-year-old boy presented signs of intracranial pressure. Initial magnetic resonance imaging revealed a triventricular internal hydrocephalus with no visible etiologic lesion. An extended investigation with the constructive interference in steady state-technique showed a mobile cystic cerebrospinal fluid-intense lesion within the third ventricle, causing transient occlusion of the foramen of Monro. A suprasellar cyst of the third ventricle is an important differential diagnosis in apparently "idiopathic" internal hydrocephalus. In such cases, magnetic resonance imaging using the constructive interference in steady state-technique with a slice thickness of 1 mm is the method of choice for detecting intraventricular cysts. Neurosurgical fenestration and/or resection of the cyst by neuroendoscopy can resolve cerebrospinal fluid circulation disturbances and seems to be superior to a shunt.

Spontaneous rupture of a presumed colloid cyst of the third ventricle--case report

An 83-year-old man presented with gait disturbance, dementia, and urinary incontinence that had progressed over 2 months. Computed tomography (CT) of the brain revealed hydrocephalus due to a well-demarcated, round hyperdense mass in the third ventricle, which was not enhanced by contrast agent. Ten days after the initial evaluation, CT revealed that the cyst in the third ventricle had disappeared. Magnetic resonance imaging revealed spontaneous rupture of the lesion and remnants of cyst wall anchored to the anterior roof of the third ventricle. Thereafter, the symptoms of hydrocephalus subsided. However, 6 months later the patient's condition gradually deteriorated and the ventricles dilated without any evidence of tumor regrowth. Surgical intervention was not performed as the family of the patient withheld consent. The natural history of colloid cysts of the third ventricle remains unclear. Spontaneous rupture of a presumed colloid cyst of the third ventricle should be considered when planning treatment.

A theory on the natural history of colloid cysts of the third ventricle

OBJECTIVE

Patients with third ventricular colloid cysts typically are diagnosed when they develop symptoms related to cerebrospinal fluid (CSF) obstruction at the foramen of Monro. However, the clinical and neuroimaging characteristics related to symptom development are poorly understood.

METHODS

From January 1974 to June 1998, 155 patients with newly diagnosed colloid cysts were managed at our center. Eighty-seven patients (56%) were thought to have tumor-related symptoms, and they underwent surgery (resection, n = 74; ventriculoperitoneal shunting, n = 11; stereotactic aspiration, n = 2). Sixty-eight patients (44%) had colloid cysts thought to be asymptomatic, and observation with serial neuroimaging was recommended. Recursive partitioning was used to examine the association of patient and tumor characteristics with the development of cyst-related symptoms.

RESULTS

Univariate analysis comparing symptomatic and asymptomatic patients revealed four factors associated with cyst-related symptoms: 1) younger patient age (44 yr versus 57 yr; P < 0.001); 2) cyst size (13 mm versus 8 mm; P < 0.001); 3) ventricular dilation (83% versus 31%; P < 0.001); and 4) increased signal on T2-weighted magnetic resonance images (44% versus 8%; P = 0.001). All four variables remained significant in a multivariate logistic regression model: patient age (P = 0.04; odds ratio, 1.0); cyst size (P = 0.04; odds ratio, 1.2); ventricular dilation (P = 0.02, odds ratio, 7.2); and increased signal on T2-weighted magnetic resonance images (P = 0.04; odds ratio, 2.7). The most significant variable was ventriculomegaly (yes versus no). Patients with normal-sized ventricles (n = 62) were further categorized by cyst size (< or = 10 mm versus > 10 mm). For patients with enlarged ventricles (n = 93), patient age (< or = 50 yr versus > 50 yr) was the most important variable. Patients older than 50 years also were split with respect to cyst size; patients aged 50 years or younger with enlarged ventricles were not affected by cyst size. The percentage of patients with cyst-related symptoms was 12, 50, and 85% in the three final patient classes, respectively. Multivariate analysis including the patient classes resulted in removal of the other significant variables from the model, whereas the patient classes remained significant (P < 0.0001; odds ratio, 6.3) for predicting patients with cyst-related symptoms.

CONCLUSION

The patient and neuroimaging characteristics of the different patient classes support a theory on the natural history of colloid cysts. Patients with third ventricular colloid cysts become symptomatic when the tumor enlarges rapidly, causing CSF obstruction, ventriculomegaly, and increased intracranial pressure. Some cysts enlarge more gradually, however, allowing the patient to accommodate the enlarging mass without disruption of CSF flow, and the patient remains asymptomatic. In these cases, if the cyst stops growing, the patient can maintain a steady state between CSF production and absorption and may not require neurosurgical intervention.

Endoscopic colloid cyst surgery

OBJECTIVE

The purpose of this report is to discuss the technical aspects of operating on colloid cysts through a transventricular approach, with rigid endoscopes.

METHODS

Twelve patients underwent 14 endoscopic operations in attempts to treat their colloid cysts. All patients were symptomatic, with headache being the most common complaint (8 of 12 patients). Six patients in this series exhibited enlarged ventricles associated with their colloid cysts. Using rigid endoscopes of < or =3.5-mm diameter, the cysts were inspected and fenestrated. Both hard and soft cyst contents were evacuated, and then the walls of the cysts were coagulated inside and outside. External ventriculostomy tubes were usually placed. Technical obstacles to successful completion of endoscopic colloid cyst surgery are discussed.

RESULTS

For 11 of the 12 patients, the colloid cysts could be treated via an endoscopic approach. The mean follow-up time was 173 weeks, and the median follow-up time was 125 weeks. For the 12th patient, bilateral scarring of the foramina of Monro precluded direct surgery; therefore, a septostomy was performed and a ventriculoperitoneal shunt was placed.

CONCLUSION

Endoscopic transventricular surgery should be considered for the treatment of colloid cysts.

Natural history of asymptomatic colloid cysts of the third ventricle

OBJECT

To determine the natural history of colloid cysts of the third ventricle in patients in whom the cysts were incidentally discovered, the authors retrospectively reviewed cases observed during the modern neuroimaging era (1974-1998).

METHODS

During this 25-year interval, 162 patients with colloid cysts were examined and cared for at our center. Sixty-eight patients (42%) were thought to be asymptomatic with regard to their colloid cyst and observation with serial neuroimaging was recommended. The mean patient age was 57 years at the time of diagnosis (range 7-88 years) and the mean cyst size was 8 mm (range 4-18 mm). Computerized tomography scanning revealed a hyperdense cyst in 49 (84%) of 58 patients. Three patients were excluded from the study because they died of unrelated causes within 6 months of scanning and seven patients were lost to follow-up review. Clinical follow-up evaluation was available at a mean of 79 months (range 7-268 months) in the remaining 58 patients. The numbers of patients who participated in follow-up review at 2, 5, and 10 years after diagnosis were 40, 28, and 14, respectively. The incidences of symptomatic progression related to the cyst were 0%, 0%, and 8% at 2, 5, and 10 years, respectively. No patient died suddenly during the follow-up interval. Two (6%) of 34 patients in whom follow-up imaging was performed either exhibited cyst growth (one patient) or experienced hydrocephalus (one patient) at a mean of 41 months after diagnosis (range 4-160 months).

CONCLUSIONS

Patients in whom asymptomatic colloid cysts are diagnosed can be cared for safely with observation and serial neuroimaging. If a patient becomes symptomatic, the cyst enlarges, or hydrocephalus develops, prompt neurosurgical intervention is necessary to prevent the occurrence of neurological decline from these benign tumors.

Rare occurrence of intracerebellar colloid cyst. Case report

Colloid cysts are rare intracerebral lesions that are preferentially encountered within the third ventricle. There are only a few reports in which colloid cysts are described in other locations such as the fourth ventricle. A symptomatic intracerebellar colloid cyst in a 45-year-old woman is described. The patient presented with headache, gait disturbance, and nausea. Neuroradiological imaging revealed compression of the fourth ventricle, hydrocephalus, and an intracerebellar cystic lesion measuring 4 x 5 cm that had a small peripheral solid portion. The cyst was successfully removed via a paramedian suboccipital approach. Postoperatively, the patient recovered quickly. The findings in the present report represent an additional example of the broad spectrum of cystic lesions encountered in the cerebellum.

Colloid cyst of the third ventricle: radiologic-pathologic correlation

We describe a patient with a large colloid cyst of the third ventricle and resultant hydrocephalus. An unenhanced brain CT demonstrated the central portion of the mass to be of increased density relative to the peripheral portion. On T1-weighted images, the central portion of the mass was of increased signal intensity relative to brain, whereas the periphery was isointense. On T2-weighted images, the central portion was markedly hypointense to brain, while the peripheral portion was isointense. These imaging findings corresponded to an actual pathological difference between the central and peripheral portions of the mass. The central portion was solid, whereas the periphery was liquid. Since no histological difference was identified between the central and peripheral portions of the mass, we hypothesize that the differences in densities on CT and signal characteristics on MR were related to the state of hydration in the mass where the central portion possibly had a higher protein concentration than the periphery.

Sudden death in an adolescent boy due to a colloid cyst of the third ventricle

A 13-year-old boy died suddenly at night while asleep. A colloid cyst filled the third ventricle, obstructed the flow of cerebral spinal fluid, and led to prominent hydrocephalus. Acute ventricular distension with brain herniation resulted in death, whereas repeated previous episodes had led to cerebral compression and edema. Complaints included only episodic headache in the month prior to death. His pediatrician prescribed a course of Imitrex (sumatriptan) because of lack of neurologic signs or other symptoms and a family history of migraine headaches. The headaches persisted, however, and within 1 month the patient died. The difficulty of accurate clinical diagnosis in this case is common. Subtle signs or even lack of symptoms of increased intracranial pressure may prevent a timely diagnosis before the occurrence of deadly complications. This case report helps to remind both forensic medical examiners and clinicians that this entity, although rare, should remain in the differential diagnosis of headache in children and young adults and of hydrocephalus at autopsy. Timely diagnosis of this benign lesion can lead to a surgical cure.