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Background Although the interforniceal approach with the preservation of the fornix is useful during the endoscopic approach for retroforaminal colloid cysts, it carries a significant risk of memory and cognitive difficulties. Because most reports have reported the endoscopic approach to colloid cysts through the foramen with little emphasis on retroforaminal cysts, the aim of this study was to investigate colloid cysts as a special entity with regard to their different characteristics and surgical approaches and outcomes. Methods In this retrospective study, 12 patients with third ventricular colloid cysts with retroforaminal extensions were included. All patients underwent endoscopic transseptal interforniceal approach with tumor resection. The surgical technique was briefly described, and preoperative and postoperative data were evaluated. Results Among the 12 patients included in this study, most of our patients were males. Average diameter of the colloid cyst was relatively large (average 22 mm). Gross total resection was achieved in 10 cases (83.3%). The stable images showed no local recurrence in the long-term follow-up period except in 1 case at the 28-month follow-up period. Conclusions Retroforaminal colloid cyst represents a unique entity that requires special attention to its mode of growth. The endoscopic approach for retroforaminal colloid cysts is nearly the same as that for foraminal cysts. It has a lower incidence rate of postoperative memory changes, lower chances of total resection, and lower incidence rate of hard contents. Moreover, sufficient knowledge on morbid anatomy is important to avoid fornix injury.

Colloid cyst are benign intracranial lesions located in the III ventricle in the region of the foramen of Monro. The majority present in the third and fourth decades of life and are rare under the age of ten. We report a case of an incidentally colloid cyst presented in a 2.5 -years-old girl who was managed conservatively; follow-up with MRI showed a progressive reduction in size. We review the four similar case previously reported.

Introduction. Cysts of the chiasmo-sellar region include Rathke cleft cysts, colloid cysts, arachnoid cysts, dermoid cysts, and epidermoid cysts.The objective was to determine the specific features of surgical treatment for each type of cysts of the chiasmo-sellar region, allowing to achieve the best postoperative results.Methods and materials. During the period from 2009 to 2018, 57 patients with cysts of the chiasmo-sellar region were examined and treated. All patients underwent transsphenoidal endoscopic treatment of cysts of the chiasmo-sellar region.Results. Among 57 operated patients, follow-up observation revealed only 2 relapses.Conclusion. For each type of cysts of the chiasmal-sellar region, there are specific features of surgical treatment that allow to achieve the best postoperative results.

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.

Introduction Acute spontaneous bleeding within a colloid cyst of the third ventricle is extremely rare. Accordingly, is difficult to establish reliable prognostic factors, risk factors for obstructive hydrocephalus remain poorly defined, and there are no standard management strategies. Case presentation 19-Year-old man with a colloid cyst of the third ventricle causing obstructive hydrocephalus is described, initially treated with partial endoscopic removal and ventriculo-peritoneal shunt placement. Serial neuroimaging follow-up showed gradual growth of the cyst due to clinically silent intracystic recurrent hemorrhage. Microsurgical transcallosal approach was performed and the cyst was totally resected. Pathological examination demonstrated hemorrhages of varying ages within the tumor. Conclusion Bleeding within a colloid cyst must be considered when neuroimaging follow-up shows cyst growth, even with no clinical events associated. Hemorrhagic changes within the colloid cyst should be considered in the surgical indication and approach.

Background The surgical approaches of colloid cysts commonly include endoscopy or open microsurgery. Each approach carries its own challenges, feasibility, and complications. The aim of the current study is to compare endoscopic versus open microsurgical excision of third ventricular colloid cysts. Methods A retrospective cohort study was conducted to compare the surgical outcomes of endoscopic versus open microsurgical (transcortical-transventricular and transcallosal approaches) excision of colloid cyst of the third ventricle at a tertiary-care medical institute. All patients with a neuroradiologic diagnosis of colloid cyst who subsequently underwent surgical management between January 2003 and June 2020 were included. The neurologic outcome was assessed at the last follow-up visit. Results A total of 32 patients with colloid cysts were included in the study. The mean age was 35.8 ± 18.3 years (range, 4–75 years). Female patients slightly outnumbered male patients (n = 17; 53.1%). A total of 21 patients (65.6%) underwent endoscopic resection of the colloid cyst. Complications were encountered in 7 patients (endoscopic, n = 3; microsurgery, n = 4; P = 0.151). Recurrence was identified in 4 patients (endoscopic, n = 3; microsurgery, n = 1; P = 0.673). Most patients improved neurologically on follow-up visits to the clinic (endoscopic, n = 19; microsurgery, n = 9; P = 0.482). Conclusions Both endoscopic and microsurgical approaches provide favorable surgical outcomes in colloid cyst resection. The complication rates between both approaches is statistically insignificant. The optimal surgical approach for colloid cyst resection remains controversial.

Although outcome studies and systematic reviews have been published on the surgical treatment of third ventricle colloid cysts (TVCC), there are no meta-analyses that compare the outcomes for various surgical approaches. This meta-analysis assesses the outcomes and complications for transcortical, transcallosal, and endoscopic surgical approaches used to excise TVCCs. A meta-analysis of surgically excised TVCCs was performed with an assessment of outcome for transcortical, transcallosal, and endoscopic approaches. A random-effects model analyzed the extent of surgical excision. The analysis included reports that compared at least two of these surgical approaches, for a total of 11 studies comprising a population of 301 patients. The transcortical approach was associated with a higher incidence of complete excision compared to the endoscopic approach (OR = 0.137, p = 0.041), with no significant differences observed between transcortical and transcallosal approaches, and between transcallosal and endoscopic approaches. Comparison between endoscopic and pooled microsurgical approaches was also insignificant (OR = 0.22, p = 1). The risk of motor weakness was increased with the transcortical approach compared to the endoscopic approach (OR = 6.10, p = 0.018). There were no significant differences between transcortical and transcallosal approaches regarding newly onset seizures, and no significant mortality differences between all three approaches. This study demonstrates that microsurgical approaches are associated with a greater extent of resection compared to endoscopic approaches; however, best results are likely achieved based on the surgeon's expertise, flexibility, and case review.

Background Third ventricle cavernous malformations (CMs) associated with ventriculomegaly and obstructive hydrocephalus are quite rare in patients. Preoperative surgical planning can be challenging due to the lesion's non-specific appearance on CT and magnetic resonance imaging that can mimic other intraventricular pathologies, such as a colloid cyst. Management of these lesions can be varied in the setting of obstructive hydrocephalus. Case Description The patient is a 78-year-old woman who first presented to her primary care provider with balance difficulties and inability to ambulate on her own. She also had bladder incontinence and progressive, severe headaches. Imaging of the brain demonstrated entrapment of the right lateral ventricle and obstructive hydrocephalus due to a lesion in the third ventricle obstructing the right foramen of Monro, thought to be a colloid cyst. A right frontal neuroendoscopic approach with direct visualization, however, confirmed a third ventricle CM. A septal pellucidum fenestration was performed to restore cerebrospinal fluid communication and no resection of the lesion was performed. The patient recovered well after the operation and at clinical follow-up reported no headaches and was walking well without a walker and with no neurological deficits. Conclusions A third ventricle CM was discovered after a neuroendoscopic approach for resection of a presumed colloid cyst in a patient with obstructive hydrocephalus. A neuroendoscopic septostomy was performed to treat the obstructive hydrocephalus and no resection was attempted. The patient suffered no complications and is at her neurologic baseline with no deficits.

Background Retraction of white matter overlying a brain lesion can be difficult without causing significant trauma especially when using traditional methods of bladed retractors. These conventional retractors can produce regions of focal pressure resulting in contusions and areas of infarct. Methods In this article, we present a retrospective case series of six patients with deep-seated intraventricular and intra-axial tumors that were approached using a ViewSite Brain Access System (tubular retractor). The authors describe a unique method of creating a pathway using a dilated glove. We shall also review the relevant literature that reports this type of surgery. Cases included three cases with third ventricular colloid cysts, one case of a third ventricular arachnoid cyst, one case with a lateral ventricular neurocytoma, and a case with a deeply seated intra-axial metastatic tumor. Results Gross total resection was achieved in five cases with small residual in the central neurocytoma operation, with no documented neurological deficit in any case. One case had persistent memory problems and one case had continuing decline from the metastatic disease. Conclusion The introduction of tubular-shaped retractor systems has offered the advantage of reducing retraction pressures and distributing any remaining force in a more even and larger distributed area, thus reducing the risk of previous associated morbidity while also permitting great visualization of the target lesion.

Background Colloid cysts are a benign tumor that is almost exclusively found in the third ventricle and may cause hydrocephalus and rarely life-threatening acute deterioration and even sudden death. With very few cases of sudden death reported in literature not much is known about the patient and cyst characteristics in these patients. The authors present a review of 65 cases of colloid cyst attributed deaths in literature. Materials and methods A literature search for sudden death with radiologically or pathologically identified colloid cyst was done on PubMed, google scholar, Medbase and clinicaltrials.org research drives. Patient demographics, symptoms and cyst characteristics were recorded and analyzed. A Bivaret Pearson correlation coefficient was used to analyze and compare the relationship between each antecedent symptom, cyst size, and, cyst hemorrhage in patients who subsequently succumbed and died in order to ascertain possible relation. Results Most patients had a history of sudden severe headaches (p = 0.01) with associated vomiting (p = 0.03). Radiologically, cyst associated ventriculomegaly was seen in 97% (P = 0.78) was a notable feature. Even more, the cyst size (p = 0.01) and associated hemorrhage (p = 0.02) were also major notable feature preceding sudden death in both gender group. Conclusion Acute deterioration in colloid cysts is rare, but can be fatal. Associated symptoms include severe headache and vomiting. Seizures are commonly seen in patients in the first two decades. Given the risk of acute deterioration and mortality, headaches should be thoroughly investigated and all patients diagnosed with a colloid cyst > 1 cm should be offered surgical management regardless of symptom profile.

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 use of minimally invasive transcranial ports for the resection of deep-seated lesions has been shown to be safe and effective. To date, most of the literature regarding the tubular retractors used in brain surgery is comprised of individual case reports that describe the successful resection of deep-seated lesions such as thalamic pilocytic astrocytomas, colloid cysts in the third ventricle, hematomas, and cavernous angiomas. The authors describe their experience using a tubular retractor system with three different cases involving large intraventricular meningiomas and examine radiographic and patient outcomes. A single-institution, retrospective case series was performed from a skull base database. Patients who underwent resection of intraventricular > 4-cm meningiomas with port technology were identified. The authors reviewed three cases to illustrate the feasibility of minimal access port surgery for the resection of these lesions. Complete resection was achieved in all cases. None of the patients developed permanent neurological deficits. There were no major complications related to surgery and no mortalities. Good clinical and surgical outcomes for atrium meningiomas can be achieved through the minimally invasive port technique and tumor size does not appear to be a limitation.

Colloid cysts are uncommon, intracranial lesions frequently arising from the anterior aspect of the third ventricle. Rarely a cyst presents greater than 30 mm diameter as a giant colloid cyst. This case reports a patient with a giant colloid cyst occupying a cavum septum pellucidum et vergae. The clinical and operative significance of this anatomical variation is discussed and the giant colloid cyst literature reviewed.

Background: Thyroid swelling continues to be prevalent in various parts of India. The swellings are to be clinically detected initially followed by imaging and tissue diagnosis. The main objective of the study was to observe clinical presentations of the thyroid swellings and to correlate the clinical diagnosis with that of pathological diagnosis. To study the spectrum of clinical presentations of thyroid swellings and the accuracy of FNAC in the diagnosis of thyroid swellings.Materials and Methods: Patients with obvious thyroid swellings were included in a prospective study which was conducted for a year in a tertiary centre. Various entities like clinical examination, ultrasonological studies and tissue diagnosis were included.Results: Out of the 65 patients included in the study, incidence of thyroid swellings was much higher in the age distribution between 30-50 years. On ultrasonographic studies, 18 patients were radiologically diagnosed with carcinoma thyroid and colloid goiter each, constituting 27.7% of the total. Another 17 cases were diagnosed with multinodular goitre with 26.2%, 4 cases with thyroiditis (6%), 3 cases with solitary thyroid nodule and hashimotos thyroiditis each (4.6%) and 2 cases of colloid cyst (3.1%). On comparison of clinical diagnosis with FNAC, of 22 cytologically diagnosed malignant cases, 16 cases were clinically diagnosed. On correlation of the histopathological findings of 65 cases with that of the fine needle aspiration cytology,60 cases matched the reports with each other, with accuracy rate of 92.30%.Whereas, of the remianing 5 cases, 3 were of follicular adenoma and of 2 cytologically diagnosed colloid cyst showed up to be colloid goitre.Conclusion: Thyroid swellings are more predominantly seen in female gender in the age group of 30- 50 years. Most of the swellings are benign in nature, of which colloid goitre is the most common in our study. Fine needle aspiration cytology (FNAC) is a valuable and cost effective pre-operative investigation for thyroid swellings. Surgical management is the definite treatment for thyroid swellings, of which total thyroidectomy is the most preferable type in our centre.

Third ventricular colloid cyst is slow-growing benign tumor comprising

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

Background Colloid cysts of the third ventricle are benign congenital lesions. They are at times totally asymptomatic or may be detected in the evaluation for headache, neurologic disturbances, or psychiatric disturbances. They may sometimes cause grave consequences such as coma or even sudden death. The radiologic appearance is unique and important for making decisions in the management. Case Description We report a patient with a colloid cyst who presented to us after sudden deterioration in consciouness. It was noted that he underwent brain computed tomography (CT) scan 10 months ago in the evaluation of headache. Compared with previous CT scan, there was a sudden change in the density and size of the colloid cyst with obstructive hydrocephalus. This unique change in the character of the colloid cyst occurred without any intervention. We discuss the possible etiologies behind this phenomenon along with a review of the literature. Conclusions This case stands out remarkably because it is only the second case in literature with similar natural history.

The presence of collision tumors without any evidence of phacomatoses, genetic syndromes, or any history of previous radiation to the brain is extremely rare. We report a case with two diverse primaries, a tentorial meningioma and a colloid cyst found in the same patient occurring in the absence of these conditions. To the best of our knowledge, a single case of a colloid cyst and meningioma found together in the same patient has been reported till date. In such cases, the surgical dilemma as to which tumor to operate first has been addressed in our case report.

Background Although endoscopic approaches are widely used for resection of colloid cysts because of the lower invasiveness, removal of the recurrent colloid cyst is still challenging. Total removal is sometimes difficult to achieve with single-port endoscopy because of the restricted access and working space. To compensate for these limitations, the dual endoscope technique via the bilateral transforaminal approach was chosen. Case Description A 34-year-old woman with recurrent colloid cyst of the third ventricle was admitted to our department. She had a history of endoscopic subtotal removal at another institution. Reoperation was scheduled and the endoscopic bilateral transforaminal approach was chosen to ensure total removal with minimum complication risk. After decompression, the cyst was retracted toward the third ventricle floor via the right foramen of Monro. Under direct inspection with an angled scope via the right foramen of Monro, the cyst attachment on the third ventricle roof was sharply dissected via the left foramen of Monro, resulting in total removal. Conclusions The dual endoscope technique via the bilateral transforaminal approach can achieve better surgical outcome by obtaining direct visualization of the cyst attachment. Although the indication should be limited, this approach can be considered especially for patients with recurrent lesions involving possible adhesion to vital structures.

Objective: Colloid cysts of the third ventricle are benign intracranial tumors. They are most commonly presented with signs of intracranial hypertension due to obstructive hydrocephalus, including headache, nausea/vomiting and vision disturbances, whereas extrapyramidal symptoms such as tremor are very rare. Sudden death, due to abruptly developed hydrocephalus, can be also observed. Although paroxysmal symptomatology attributed to the intermittent obstruction of the foramen of Monro is considered the “classical” clinical presentation, it is rather the exception in clinical practice. Case Report: A 42-year-old woman with no medical history was admitted to the neurology department as suffering from a potential demyelinating disease due to episodes of paroxysmal tremor of her right lower limb and persistent mild gait instability, which presented 15 days prior to her arrival. She also complained of episodes of partially position-dependent bilateral headache over the last 10 years, as well as episodes of vertigo over the last 4 years. On arrival, her gait was shuffling and mildly wide-based and an intermittent tremor of her right lower limb was observed in supine and sitting positions, but not in a prone position. Brain magnetic resonance imaging (MRI) demonstrated a round cystic lesion of the third ventricle, accompanied by hydrocephalus with enlargement of lateral ventricles. MRI findings were highly indicative of a colloid cyst. The patient underwent resection of the mass and the tremor resolved after surgery. Conclusion: Given the greatly heterogeneous clinical presentation of colloid cysts, our case highlights the significance of the prompt diagnosis of this rare but potentially fatal cause of paroxysmal limb tremor.

Undiagnosed significant hydrocephalus is an uncommon finding at forensic autopsy as many cases present in life with complex neurological symptoms. We present a case of a 46-year-old man with no neurological deficits or history of head trauma that was incidentally found to have a massive hydrocephalus at autopsy. This was found to be associated with an unruptured arteriovenous malformation completely confined to the choroid plexus as well as complete agenesis of the corpus callosum. The arteriovenous malformation was found to form a calcified obstruction at the foramen of Monro analogous to a mass lesion, such as a colloid cyst of the third ventricle. The association of this malformation and agenesis of the corpus callosum has never been described. Histologic examination of the brain confirmed significant loss of white matter tracts and thinning of the cortical ribbon due to pressure atrophy of the ependymal lining without significant gliosis, cortical dysplasia, or evidence of other developmental malformations. Autopsy is a vital tool in the evaluation of such rare cases, enhances epidemiologic data, and increases the understanding of these pathophysiological associations.

Lesions located in subcortical areas are difficult to safely access. Tubular retractors have been increasingly used successfully with low complication profile to access lesions by minimizing brain retraction trauma and distributing pressure radially. Both binocular operative microscope and monocular exoscope are utilized for lesion visualization through tubular retractors. We present the largest multi-surgeon, multi-institutional series to determine the efficacy and safety profile of a transcortical-transtubular approach for intracranial lesion resections with both microscopic and exoscopic visualization. We reviewed a multi-surgeon, multi-institutional case series including transcortical-transtubular resection of intracranial lesions using either BrainPath (NICO, Indianapolis, Indiana) or ViewSite Brain Access System (VBAS, Vycor Medical, Boca Raton, Florida) tubular retractors (n = 113). One hundred thirteen transtubular resections for intracranial lesions were performed. Patients presented with a diverse number of pathologies including 25 cavernous hemangiomas (21.2%), 15 colloid cysts (13.3%), 26 GBM (23.0%), two meningiomas (1.8%), 27 metastases (23.9%), 9 gliomas (7.9%) and 9 other lesions (7.9%). Mean lesion depth below the cortical surface was 4.4 cm, and mean lesion size was 2.7 cm. A gross total resection was achieved in 81 (71.7%) cases. Permanent complication rate was 4.4%. One patient (0.8%) experienced one early postoperative seizure ( 1 week follow-up). Mean post-operative hospitalization length was 4.1 days. Tubular retractors provide a minimally invasive operative corridor for resection of intracranial lesions. They provide an effective tool in the neurosurgical armamentarium to resect subcortical lesions with a low complication profile.

Background Colloid cysts are benign and rare tumors of the brain. The growth rates of these tumors are unpredictable. These cysts can increase in size and obstruct the cerebrospinal fluid pathways producing obstructive hydrocephalus. Consequently, this can manifest as acute severe headaches followed by deterioration in consciousness, or even sudden death in patients. Such remarkable episodes occurring in patients during air travel have been reported sparsely in the literature. Case Description In this report, we narrate the ordeal of a patient who had severe headache followed by loss of consciousness during his air travel. After his arrival, he was taken to a referral center where the diagnosis of a colloid cyst obstructing the cerebrospinal fluid pathway resulting in acute obstructive hydrocephalus was revealed. We analyze the physiologic effects of cabin pressure and high altitude on the intracranial pressure and present a brief review of the literature. Conclusions Changes in cabin pressure during flight may play a role in worsening of intracranial pressure in patients with colloid cyst with marginal brain compliance.

Introduction:The plasticity of the neural circuits after injuries has been extensively investigated over the last decades. Transcallosal microsurgery for lesions affecting the third ventricle offers an interesting opportunity to investigate the whole-brain white matter reorganization occurring after a selective resection of the genu of the corpus callosum (CC).MethodDiffusion MRI (dMRI) data and neuropsychological testing were collected pre- and postoperatively in six patients with colloid cysts, surgically treated with a transcallosal-transgenual approach. Longitudinal connectometry analysis on dMRI data and graph analysis on structural connectivity matrix were implemented to analyze how white matter pathways and structural network topology reorganize after surgery.ResultsAlthough a significant worsening in cognitive functions (e.g., executive and memory functioning) at early postoperative, a recovery to the preoperative status was observed at 6 months. Connectometry analysis, beyond the decrease of quantitative anisotropy (QA) near the resection cavity, showed an increase of QA in the body and forceps major CC subregions, as well as in the left intra-hemispheric corticocortical associative fibers. Accordingly, a reorganization of structural network topology was observed between centrality increasing in the left hemisphere nodes together with a rise in connectivity strength among mid and posterior CC subregions and cortical nodes.ConclusionA structural reorganization of intra- and inter-hemispheric connective fibers and structural network topology were observed following the resection of the genu of the CC. Beyond the postoperative transient cognitive impairment, it could be argued anterior CC resection does not preclude neural plasticity and may subserve the long-term postoperative cognitive recovery.

OBJECTIVE Colloid cysts (CCs) are rare at all ages, and particularly among children. The current literature on pediatric CC is limited, and often included in mixed adult/pediatric series. The goal of this multinational, multicenter study was to combine forces among centers and investigate the clinical course of pediatric CCs. METHODS A multinational, multicenter retrospective study was performed to attain a large sample size, focusing on CC diagnosis in patients younger than 18 years of age. Collected data included clinical presentation, radiological characteristics, treatment, and outcome. RESULTS One hundred thirty-four children with CCs were included. Patient age at diagnosis ranged from 2.4 to 18 years (mean 12.8 ± 3.4 years, median 13.2 years, interquartile range 10.3–15.4 years; 22% were < 10 years of age). Twenty-two cases (16%) were diagnosed incidentally, including 48% of those younger than 10 years of age. Most of the other patients had symptoms related to increased intracranial pressure and hydrocephalus. The average follow-up duration for the entire group was 49.5 ± 45.8 months. Fifty-nine patients were initially followed, of whom 28 were eventually operated on at a mean of 19 ± 32 months later due to cyst growth, increasing hydrocephalus, and/or new symptoms. There was a clear correlation between larger cysts and symptomatology, acuteness of symptoms, hydrocephalus, and need for surgery. Older age was also associated with the need for surgery. One hundred three children (77%) underwent cyst resection, 60% using a purely endoscopic approach. There was 1 death related to acute hydrocephalus at presentation. Ten percent of operated patients had some form of complication, and 7.7% of operated cases required a shunt at some point during follow-up. Functional outcome was good; however, the need for immediate surgery was associated with educational limitations. Twenty operated cases (20%) experienced a recurrence of their CC at a mean of 38 ± 46 months after the primary surgery. The CC recurrence rate was 24% following endoscopic resection and 15% following open resections (p = 0.28). CONCLUSIONS CCs may present in all pediatric age groups, although most that are symptomatic present after the age of 10 years. Incidentally discovered cysts should be closely followed, as many may grow, leading to hydrocephalus and other new symptoms. Presentation of CC may be acute and may cause life-threatening conditions related to hydrocephalus, necessitating urgent treatment. The outcome of treated children with CCs is favorable.

Objective Recognition memory is widely accepted as a dual process-based model, namely familiarity and recollection. However, the location of their specific neurobiological substrates remains unclear. Similar to hippocampal damage, fornix damage has been associated with recollection memory but not familiarity memory deficits. To understand the neural basis of recognition memory, determining the importance of the fornix and its hippocampal connections is essential. Methods Recognition memory was examined in a 45-year-old male who underwent a complete bilateral fornix section following the removal of a third ventricle colloid cyst. The application of familiarity and recollection for recognition memory decisions was investigated via an immediate and delayed associative recognition test and an immediate and delayed forced-choice task in the patient and a control group (N = 15) over a two-year follow-up period. Complete demographic, neuropsychological, neuropsychiatric, and neuroradiological characterizations of this patient were performed. Results Persistent immediate and delayed verbal recollection memory deficits were observed in the patient. Moreover, delayed familiarity-based recognition memory declined gradually over the follow-up period, immediate familiarity-based recognition memory was unaffected, and reduced non-verbal memory improved. Conclusion The present findings support models that the extended hippocampal system, including the fornices, does not appear to play a role in familiarity memory but is particularly important for recollection memory. Moreover, our study suggests that bilateral fornix transection may be associated with relatively functional recovery of non-verbal memory.

BACKGROUND : Colloid cysts are one of the rare brain tumours and are mostly located in the anterosuperior portion of the third ventricle, between the fornix and surround of Foramen of Monroe. OBJECTIVES: Ÿ 1.To review the demographic information & analyse clinical manifestations of patients presenting with colloid cyst of third ventricle. Ÿ 2.To analyze the advantages and disadvantages of various surgical approaches Ÿ 3.To assess the surgical outcome in colloid cyst patients operated by any method. MATERIALS AND METHODS: A retrospective study was performed on 16 patients who presented with a colloid cyst and underwent surgery at the Department of Neurosurgery, King George Hospital, Andhra Medical College between 2013-2018. They were evaluated based on clinical ndings and imaging features, surgical approaches used for resection and their outcomes. RESULTS: Sixteen cases of colloid cyst of the third ventricle were operated upon between 2013-2018. There were seven male and nine female patients with their ages varying between 9 and 62 years old. Nine patients were operated on by using a transcortical trans-ventricular approach, four using the anterior trans-callosal approach and, three patients by using an endoscopic approach. In all patients, complete excision of the lesions was achieved. CONCLUSION: Colloid cysts, though benign, present surgical challenges because of its deep midline location. Complete excision of the colloid cyst carries an excellent prognosis. Surgery is a safe and effective treatment option for this benign lesion.

The Colloid Cyst Risk Score (CCRS) was devised to identify patients with symptomatic colloid cyst and stratify risk of hydrocephalus. The CCRS considers patient age, presence of headache, colloid cyst diameter, fluid-attenuated inversion recovery hyperintensity, and location within the third ventricle.The purpose of this study was to independently evaluate the validity of the CCRS.Patients with a colloid cyst of the third ventricle were identified retrospectively from institutional billing records and radiology report archives. Patients without a confirmed diagnosis of colloid cyst of the third ventricle or magnetic resonance imaging of the brain were excluded. Data were collected via retrospective chart review.One hundred and fifty-six patients met inclusion and exclusion criteria. In our cohort, the CCRS stratified symptomatic patients and patients with hydrocephalus across all scores (P0.001). From CCRS 2 to 5, the percentage of symptomatic patients increased from 13% to 100%, whereas the percentage of patients with hydrocephalus increased from 8% to 83%. Simple logistic regression showed that total CCRS, headache, axial diameter, fluid-attenuated inversion recovery hyperintensity, and risk zone were all highly predictive of symptomatic status and hydrocephalus (P0.001). Logistic regression with receiver operating curves for the CCRS showed an area under the curve of 0.914 for symptomatic colloid cysts and an area under the curve of 0.892 for colloid cysts with hydrocephalus.Our data analysis validates the predictive value of the CCRS for both symptomatic status and hydrocephalus and supports the use of the CCRS in risk stratification and clinical decision making.

Background: Colloid cyst of the third ventricle is a tumour arising from the roof of the third ventricle at the foramen of Monro. Endoscopic excision of colloid cyst is well established technique. There is less morbidity in comparison to the microsurgical resection. Materials and method: Seven patients with colloid cyst were treated with endoscopic excision. Of these five were males and two were female patients. Age ranged thirty to fifty five years from a period from Jan 2016 to Mar 2019 in NINS&H. Results: Most patients had signs of raised intracranial pressure before surgery. Six patients needed post operative VP shunt. Some patients had contusion of the fornix but did not have any memory impairment. Five patients had remnant but there was no symptoms after surgery. Conclusion: Endoscopic excision of the colloid cyst is a good option. Total removal of the tumour is the goal but little remnant of the tumour attached to the tela choroidae is accepted. One year follow-up showed no recurrence of the cyst. Bang. J Neurosurgery 2020; 9(2): 94-98

Aim: To evaluate the role of ultrasound as the primary diagnostic imaging modality in thyroid disease.Methodology: Patients suspected to have thyroid disease were included in the study. Ultrasound was done as initial diagnostic imaging method for thyroid lesions and evaluated accordingly. These thyroid lesions were subjected to ultrasound guided FNAC, for confirmation of diagnosis. Later the validity of ultrasound diagnosis in relation to FNAC diagnosis was studied.Results: Ultrasonography showed relatively high sensitivity and specificity for diagnosing and characterizing thyroid disease. For thyroid adenomas, colloid cyst and multinodular goiter, the sensitivity of ultrasound was 98.55% and specificity in our study was 100%/. USG could considerably differentiate malignant and non-malignant thyroid lesions. USG showed relatively high diagnostic rate. USG guided FNAC was a safe procedure and yielded high diagnostic yield for detection of thyroid diseases.Conclusion: Above data suggests that USG can be used as a primary imaging modality with high sensitivity and specificity for overall diagnosis and characterization of thyroid diseases. USG helps in guiding FNAC for confirmation of diagnosis.

Background Developments in frameless neuronavigation and tubular retractors hold the potential for minimizing iatrogenic injury to the overlying cortex and subcortical tracts, with improved access to the ventricular system. The objective of the present study was to evaluate the surgical outcomes after resection of third ventricular colloid cysts using an integrated neuronavigation and channel-based approach. Methods We performed a multicenter retrospective analysis of surgical Outcomes after surgical resection of third ventricular colloid cysts via a transtubular trans-sulcal approach. Results A total of 16 patients were included, with a mean age of 42 years (range, 23–62 years). The mean maximum diameter of cysts was 14 mm (range, 7–28 mm), and preoperative hydrocephalous was present in 12 patients (75%). Gross total resection was achieved in all 16 cases. Of the 12 patients, 4 (25%) had undergone septum pellucidotomy, in addition to cyst resection. No case had required conversion to open craniotomy. No perioperative mortalities occurred. Three patients (18.8%) had developed transient memory deficits, 1 of whom had also developed a pulmonary thromboembolism. The median length of hospital stay was 4 days (range, 2–18 days). All the patients reported resolution of preoperative symptoms at the 1-month follow-up examination. Only 1 patient (6.25%) had required insertion of a ventriculoperitoneal shunt. The median follow-up duration was 6.5 months (range, 3–24 months), and no recurrences were observed. Conclusion Use of a channel-based navigable retractor provided a minimal trans-sulcal approach to third ventricular colloid cysts with the benefit of bimanual surgical control in an air medium for definitive resection of third ventricular colloid cysts.

Background Traditional manual retraction to access deep-seated brain lesions has been associated with complications related to vascular compromise of cerebral tissue. Various techniques have been developed over time to minimize injury, such as self-sustaining retractors, neuronavigation, and endoscopic approaches. Recently, tubular retractors such as the ViewSite Brain Access System (VBAS; Vycor Medical Inc.) have been developed to reduce mechanical damage from retraction by dispersing the force of the retractor radially over the parenchyma, thus we sought to review the current literature to accurately assess the indications, benefits, and complications associated with use of VBAS retractors. Methods A literature search for English articles published between 2005 and 2019 was performed using the MEDLINE database archive with the search terminology “Vycor OR ViewSite OR Brain-Access-System NOT glass”. The Vycor™ VBAS website was also examined. Only articles detailing neurosurgical procedures using the VBAS tubular retractor system alone, or in combination with other retractors were included. Post-operative morbidity and mortality were analyzed to estimate complications linked to using the retractor. Results Twelve publications (n=106 patients) met the inclusion criteria. The VYCOR retractor was used for tumor resections, hematoma evacuations, cyst removal, foreign body extractions, and lesion resection in toxoplasmosis and multiple sclerosis. These cases were subdivided into groups based on lesion location, size, and resection volume for further analysis. Gross-total resection was achieved in 63% of tumor excisions and subtotal resection in 37%. Hematoma evacuation was successful in all cases. There were 3 short-term postoperative complications linked to the retractor with an overall complication rate of 2.8%. Conclusions This report is the first formal assessment of the VBAS, highlighting technical considerations of the retractor from the surgeon’s perspective, patient outcomes, and complications. VYCOR retractor is a safe, efficacious tubular retraction system that can be used for tumor biopsy and resection, colloid cyst removal, hematoma evacuation, and removal of foreign bodies. However, further randomized controlled trials are indicated to accurately assess complication rates and outcomes.

Endoscopic surgery has truly revolutionized the surgical management of colloid cysts. Their central and deep location within the third ventricle has historically demanded a great degree of surgical skill and demand on the patient. Until the last two decades the treatment options for patients with colloid cysts included a traditional craniotomy (opening the skull for removal of the cyst), stereotactic cyst aspiration, or placement of a shunt for hydrocephalus.

Background: There is controversy about the value of endoscopic methods compared to microsurgical methods in the treatment of challenging colloidal cysts. This study aimed to review the findings of literature which studied microsurgery or neuroendoscopy in the colloid cyst. Methods: An advanced search in PubMed, Science Direct, and Google Scholar databases performed using keywords such as: "microsurgery," "endoscopy," "microsurgery versus endoscopy," and "colloid cysts." Results: Reviewing the findings of related studies showed some differences in sections of surgical management, microsurgery, endoscopy, complete cyst resection, recurrence rate, length of stay, and complications between the two surgical methods in the treatment of colloid cyst. Conclusion: Despite some disadvantages of endoscopy, it seems this method has more privileges than the other methods.

Introduction: Endoscopic excision of colloid cysts a minimally invasive and highly effective technique in management of third ventricular colloid cyst. Materials and Methods: Clinical and radiological data of patients undergoing endoscopic colloid cyst excision were retrospectively analyzed in the period July 2017 to August 2018. Operative video were analyzed for the colloid cyst anatomy and the surgical technique used. Results: Five cases underwent endoscopic surgery during the study period. Three patients had dilated foramen, two patients had retroforaminal type and coapted type of morbid endoscopic anatomy. Gross total excision could be achieved in two patients, two patients had near total excision and one patient had partial excision who had intraventricular bleed which was managed. There was no mortality. All the patients return to their respective jobs postoperatively. Conclusion: Endoscopic excision is a safe and effective surgical technique for colloid cyst excision. The extent of excision depends on the experience of surgeon and the endoscopic anatomy of the colloid cyst. Keywords: Colloid CYST, Third Ventricle, Endoscopic, Neuroendoscopic excision

Background: The endoscopic surgery to third ventricular lesions are now widely used as it is less invasive than the traditional microsurgical procedures.Aim of Study: To evaluate endoscopic surgery of third ventricular lesions as regards clinical improvement, compli-cation rate and extent of lesion resection.Patients and Methods: Retrospectively eleven cases of third ventricular lesions (seven cases of colloid cyst, two cases of astrocytoma, one case epidermoid cyst and 1 case of arachnoid cyst) were operated upon through endoscopic route for total excision if feasible, pre-operative assessment in the form of full neurological examination and imaging (CT and MRI) were done for all patients. Incompletely removed lesions were managed by a septostomy and VP shunt, post-operatively CT was performed in the first 24 hours after surgery and another after 48 hours, MRI with contrast was done 6 months post-operatively to detect recurrence, patients with persistent post-operative hydrocephalus had VP shunt insertion.Results: Complete resection was achieved in nine patients (82%), while resection was incomplete in two cases (18%). complications were in one case (9%) in the form of short memory affection improved after one month, post-operative hydrocephalus was in one patient (9%), mean length of hospital stay was three and half days, no recurrence was reported in all patients with complete resection for a follow-up period of 12 months.Conclusion: Endoscopic resection of third ventricular lesions is safe, minimally invasive, technically feasible and with good outcome especially in completely removed lesions.

Background The fornix is a region of greatest neurosurgical interest in regards to its complex anatomy and surgical approaches to this area. The objective of this study was to evaluate the morphology of the triangular recess (TR) and its role in the growth pattern of the colloid cysts (CC) within the third ventricle and in the choice of the surgical approach for their removal. Furthermore, to compare the results of the dissections with measurements performed on a magnetic resonance imaging scan. Methods In the anatomic study, 20 cadaveric specimens were dissected and analyzed. In the radiologic study, a magnetic resonance imaging scan was performed in 20 healthy volunteers. In the clinical study, a retrospective analysis of all the patients affected with CCs microsurgically removed at our institute between 2010 and 2018 was conducted. Results In the anatomic study, the width, height, and the area of the TR were respectively 0.31 cm, 0.33cm, and 0.051 cm2. In the radiologic study, 3 different typologies of TR were identified: open recess in ventriculomegaly (7 patients); open recess in physiologic ventricular system (3 patients); closed or blind recess (10 patients). Three different growth patterns of CCs were identified: type 1) CCs localized at the foramen of Monro growing behind the fornix and below the third ventricular roof; type 2) CCs growing rostrally between the column of fornix; and type 3) CCs growing above the plane of the third ventricular roof. Conclusions The anatomy of the TR influences the growth pattern of CC within the ventricular cavity and determines the surgical strategy for their removal.

Background Colloid cysts (CC) have been associated with neurocognitive function (NCF) decline, both preoperatively and after resection. Factors such as local pressure on the fornix and hydrocephalus are thought to contribute to preoperative NCF decline. The potential cause of postoperative decline is thought to be forniceal injury during surgery. In the current series, we describe NCF outcomes amongst patients with CC, both nonoperated and operated. Methods A total of 36 patients (23 operated, 13 nonoperated) were included in this retrospective study. All patients underwent at least 1 NCF evaluation battery. Of the 13 nonoperated cases, 5 had follow-up tests too. Of the 23 operated, 14 had both pre- and postoperative tests, and 8 had early and late postoperative tests. Results There was no significant difference in baseline NCF between nonoperated and operated cases (as evaluated preoperatively). Nonoperated patients had a stable NCF test over time. Patients who were operated showed a significant improvement after surgery in several NCF variables. There was no significant change in NCF between early and late postoperative evaluation. None of the operated patients had a postoperative NCF decline. Conclusions Patients with CC should undergo routine NCF testing with a standardized protocol, whether they are operated or followed. Surgery has a positive impact on NCF; however, it remains to be determined if the improvement is solely secondary to treatment of hydrocephalus, or to a reduction of local pressure on the fornices. It remains to be determined whether the surgical technique, that is, endoscopic, interhemispheric, or transcortical, has an impact on NCF outcome.

Background Optimal management of third ventricular colloid cysts remains debated. While microsurgery offers greater resection rates and lower recurrences, endoscopy offers a perceived less invasive option. Objective To describe the evolution of our practice to favor microsurgery and determine the optimal management of recurrent colloid cysts. Methods Any patient having undergone surgery for a colloid cyst by the senior author was identified and included in the study cohort. Clinical, radiographic, and operative records were reviewed, with attention paid to those patients requiring recurrent surgery. Results Thirty-three patients were treated for intracranial colloid cysts between 1995 and 2017. Two patients had initial surgical treatment at an outside institution prior to presentation at our institution. Microsurgery was used in 15/31 initial cases, endoscopy in 13 cases, and ventriculoperitoneal shunting in 3 cases. Between 1995 and 2005, 89% of colloid cysts (8/9 cases) were resected endoscopically, whereas 74% of colloid cysts (14/19 cases) were resected by microsurgery after 2005. Of the 13 patients treated endoscopically, 6 (46%) required surgery for recurrent cysts. Incomplete cyst wall resection at the initial operation increased the recurrence rate to 55%. There were no recurrences in the microsurgery cohort. Conclusion Surgical resection of recurrent colloid cysts should focus on complete removal of the cyst wall to minimize the chance of recurrence. Microsurgery has been shown to provide the highest success rates for cyst wall resection and lowest rates of recurrence and is therefore recommended for patients undergoing surgery for primary and recurrent colloid cysts.

Purpose To determine the incidence of the ‘dot sign’ in patients with colloid cysts of the third ventricle and to characterise its MRI appearances. Materials and Methods Single institution retrospective analysis between January 2007 and October 2016 of all patients with either an imaging or imaging and histology-confirmed diagnosis of colloid cysts of the 3rd ventricle was undertaken. For all cases, MRI signal intensities of the cyst fluid component were graded by two independent radiologists relative to brain parenchyma. Presence of a dot, and if present, its size and relative position within the cyst were recorded. Signal intensities of the dot were then similarly assessed. Results 37 cases of colloid cyst were identified. Of these 37.8% (n = 14) demonstrated the dot sign. The majority (11 of 14) were observed inferiorly within the cyst; two cases were anteroinferior, and one other was posterior. All identified intracystic nodules displayed low signal intensity with respect to cyst fluid on T2 weighted sequences, and only two nodules were hypointense to fluid on T1-weighted imaging, with the remainder either iso- or hyperintense. Conclusions An intracystic low T2 ‘dot’ is a common MRI feature of colloid cysts of the third ventricle, and to our knowledge not previously systematically described. Presence of such a dot should not only not dissuade from a diagnosis of colloid cyst being made, but should in fact be used to strengthen the imaging diagnosis.

Background Colloid cysts (CCs) are rare cystic lesions derived from the endoderm of the central nervous system. Although they appear most commonly in the anterior roof of the third ventricle, there are only a few reports of CCs located in the suprasellar region. Although CCs are considered to be slow-growing benign tumors, their developmental process remains unclear. Case Description A 6-year-old boy was referred to our hospital for a mild head injury. Head computed tomography scan revealed a round, hyperdense suprasellar lesion, while magnetic resonance imaging depicted the mass as an isointense lesion with multiple highly hypointense spots on T2-weighted imaging. Although this lesion had been managed conservatively with annual magnetic resonance imaging follow-up, its size gradually increased, resulting in an increase in diameter by a factor of 1.5 over an 11-year period. The doubling time of this tumor was estimated to be approximately 7 years. Despite its asymptomatic nature, the cystic lesion was totally resected when the patient was 17 years of age using an endoscopic endonasal approach to make a definitive histologic diagnosis and prevent the occurrence of neurologic symptoms. The postoperative course was uneventful, and the histologic diagnosis of the surgical specimen was consistent with CC. Conclusions This case suggests that CC may be one of several possible diagnoses in patients who present with suprasellar cystic lesions. Even if CCs in the suprasellar region remain asymptomatic, radiological follow-up is required due to possible progressive enlargement of the cyst.

Background Endoscopy is increasingly being adopted for removing colloid cysts. However, the neuropsychological outcome and quality of life (QOL) have not been studied in detail. This study is to evaluate the efficacy of endoscopic excision on cognitive measures and QOL. Methods Patients with colloid cysts larger than 7 mm, undergoing endoscopy were prospectively studied concerning clinico-radiology, cognitive parameters (age and education adjusted), extent of resection and recurrence. A cross-sectional QOL assessment was additionally performed on endoscopic patients in comparison with cases who underwent microsurgery or standalone ventriculo-peritoneal (VP) shunt. Results A total of 22 endoscopic patients with a mean age of 34 years and a mean cyst diameter of 19 mm were studied. Gross total resection(GTR) could be achieved in all. Over a mean follow-up of 53.4 months, none had a recurrence, ventriculomegaly, or retreatment. Among neuropsychological parameters, digit span was the most affected before surgery. There was a broad-based improvement in the mean global cognitive score from 40.63(±10.4) at baseline to 50.25(±5.8) after endoscopy with maximum improvement in 'immediate recall.' The change in scores also had a significant inverse correlation with cyst size, with cysts larger than 18 mm, resulting in lower scores following endoscopy(R=−0.9, P=0.01). QOL was significantly influenced by visual and cognitive impairments and was better among endoscopic patients than similar microsurgery or VP shunt controls, with a significant difference in social and environmental domains(P=0.02). Conclusion Endoscopy is effective in achieving GTR and long-term control, with neuropsychological improvement correlated with cyst size. This is probably the first report to show QOL is influenced by cognitive parameters and is better following endoscopy than after microsurgery or VP shunt.

Colloid cyst of third ventricle is a rare, benign, congenital lesion that usually presents with headache, and associated with altered cognition, nausea, vomiting, gait ataxia, and blurred vision. A large cyst/growing cyst can cause obstructive hydrocephalus leading to acute rapid neurological deterioration and sudden death. Here we report a classic clinical presentation and histopathological features of colloid cyst of third ventricle with specific emphasis on the importance of rapid diagnosis and management to avoid potentially fatal complications of this otherwise benign lesion. Newer modalities like neuroendoscopy or stereotactic aspiration of cyst are now the preferred choices of management. Awareness of this entity for early diagnosis and management with minimally invasive procedures such as neuroendoscopy or stereotactic aspiration of cyst is crucial for better prognosis and patient care.

PURPOSE The surgical approach for colloid cysts of the third ventricle mainly consists of endoscopic or microscopic approach but few studies compare the neurologic outcomes and complications related to the different approaches. We retrospectively reviewed our results after resection of colloid cysts of the third ventricle using endoscopic surgery (ES) compared to open microsurgery (OS). METHODS Fifty-one patients were included in the study of which 17 patients underwent ES. Colloid cyst size and Evans' index were evaluated on CT or MRI scans. Presenting symptoms, neurologic outcomes and complications were compared between the two groups and analysed using Fisher's exact test. Operative time and days of hospital stay were compared between the two groups, using independent sample t-test. The median follow-up time was 96 days and did not differ significantly between the groups. RESULTS Shorter mean operative time (p = 0.04) and fewer days of hospital stay (p

Metastatic lesions to the choroid plexus, although far less common than colloid cysts, can present very similarly both symptomatically and radiographically. Choroid plexus metastases are most common in the lateral ventricles, however, when they occur in the third and fourth ventricles they may cause obstructive hydrocephalus typical of a colloid cyst lesion. Renal cell carcinoma is the most common primary cancer, but many rare primaries have been reported. When patients are presenting with symptoms typical of colloid cysts it is important to consider past oncological history and if past medical history is significant for cancer using MR spectroscopy may be valuable in distinguishing between cystic and metastatic lesions.

BACKGROUNDColloid cysts of the posterior third ventricle are exceedingly rare. This location is a high-risk zone for colloid cysts because of potential obstruction of the cerebral aqueduct.OBSERVATIONSThe authors report a case of a 57-year-old man who presented with a 6-month history of progressive headache, short-term memory loss, visual blurring, and an episode of double vision. Magnetic resonance imaging (MRI) revealed a colloid cyst, 22 mm in diameter, attached to the roof of the posterior third ventricle. The posterior third ventricle was obstructed, but both foramina of Monro were patent. The entirety of the cyst was resected via a right frontal parasagittal, interhemispheric, transventricular approach through the foramen of Monro. It was not contained within the velum interpositum. The patient did not experience any postoperative deficits.LESSONSThis case supports the theoretical evidence that colloid cysts in the posterior zone of the third ventricle pose a risk for obstructive hydrocephalus. This report of a large cyst in a rare location describes a unique lesion and provides the first published MRI description.

BACKGROUND AND PURPOSE Colloid cysts are relatively rare intracranial lesions located in the rostral aspect of third ventricle. They may produce acute hydrocephalus, brain herniation, and death. On conventional MRI, the appearance of a colloid cyst varies depending on its composition. Small isointense cysts can be missed. The purpose of this study is to introduce a new sign, "black rim susceptibility" sign for the accurate diagnosis of colloid cyst on susceptibility weighted imaging (SWI). METHODS A retrospective case-control study consisted of 100 MRI brain scans (19 cases and 81 controls) performed from January 2012 to September 2018. Two fellowship trained neuroradiologists individually interpreted SWI sequences for the presence of the "black rim susceptibility" sign (thin rim of dark signal along the periphery of a rounded, hyperintense focus). RESULTS The sample was 43% male and 57% female, with an average age of 51.8 ± 17.7. Out of 19 cases, 9 had undergone surgery in which pathology had confirmed colloid cyst. Sensitivity, specificity, and accuracy for reader 1 was 94.8%, 98.8%, and 98% and for reader 2 was 89.5%, 100%, and 98%, respectively. Positive predictive value and negative predictive value for reader 1 was 94.7% and 98.8% and for reader 2 was 100% and 97.6%, respectively. Interrater correlation between the two readers was calculated with kappa of 0.93. CONCLUSION The black rim susceptibility appearance of colloid cyst on SWI is a novel description and an effective sign that can be used by radiologists for accurate diagnosis.