Distinguishing Encephaloclastic Lesions Resulting From Primary or Secondary Pyruvate Dehydrogenase Deficiency From Other Neonatal or Infantile Cavitary Brain Lesions.

The central nervous system (CNS) is a highly complex and energy-dependent organ that is subject to a wide variety of metabolic, hypoxic-ischemic, and infectious insults that result in cystic changes. Diagnosis of metabolic defects causing extensive cystic changes is particularly challenging for the pediatric pathologist, due to the rarity of these conditions. Pyruvate dehydrogenase (PDH) deficiency is one of the most common etiologies of congenital lactic acidosis, caused by mutations in subunits of the large mitochondrial matrix complex, and characterized by periventricular cysts, although few detailed reports focusing on neuropathologic findings exist. In addition, rare defects in other mitochondrial enzymes such as short-chain enoyl-CoA hydratase (SCEH, encoded by ECHS1 gene) can cause secondary PDH deficiency and present with neonatal lactic acidosis, but neuropathological findings have never been reported. Nonmetabolic conditions can also produce CNS cystic lesions, primarily in newborns. The pathologist must therefore distinguish between these etiologically disparate conditions which can produce CNS cavitary lesions. Here, we compare and contrast the gross and microscopic findings of cysts associated with cases of PDH and SCEH deficiencies with other neonatal cystic brain diseases including periventricular leukomalacia, neonatal Alexander disease, Canavan disease, and a case of cysts associated with a vascular abnormality. Our studies show that PDH and SCEH deficiencies are not grossly or histologically distinguishable from each other and both are associated with smooth-walled cysts largely limited to the telencephalic germinal matrix. Both show an absence of prominent hemosiderin deposits, Rosenthal fibers, vacuolization of the white matter, and gliosis or axonal damage in the surrounding parenchyma. These features can help distinguish PDH/SCEH deficiency from other pediatric/neonatal cystic CNS disorders, especially those produced by hypoxic ischemic conditions. Cysts, usually bilateral, confined to the telencephalic germinal matrix should elicit metabolic and genetic testing to appropriately diagnose PDH and SCEH and distinguish them from each other.

Evolution of cerebellar tonsillar ischemia to cerebellar tonsillar cysts in the Chiari I malformation: radiological, surgical, and histological evidence.

BACKGROUND: Rare reports in the literature have documented the presence of a cyst at the tip of the cerebellar tonsil in patients with Chiari I malformation. The current study aimed to better elucidate these cysts and identify their etiology via a histological and radiologically analysis. PATIENTS AND METHODS: We prospectively reviewed all new Chiari I malformation (CM-I) patients who presented to our clinic during a 2-year period. This was a pediatric cohort made up of 340 children aged 3 to 18 years. Specifically, all patients were screened for ischemic or cystic lesions of the herniated cerebellar tonsils on MRI. RESULTS: Out of 340 patients, 2.9 % were found to have signal changes on MRI consistent with ischemia or cysts in the cerebellar tonsils. Of the 340 patients, 20 % underwent posterior fossa decompression. Of the 67 patients, cerebellar tonsillar ischemia was observed in 10.4 % and cerebellar tonsillar cysts were seen in 6 %. Four of the seven operative patients with cerebellar tonsillar ischemia and concomitant syringomyelia and three of these patients with tonsillar cysts concomitant syringomyelia and cerebellar tonsillar cysts underwent subpial dissection of some cerebellar tonsil to ensure that CSF egress from the fourth ventricle to the cervical subarachnoid space, and this transected tissue was also sent for histological analysis. Three of the four patients found to have intraoperative tonsillar cysts were noted to have tonsillar ischemic changes on preoperative imaging in this same region. For both ischemic and cystic cerebellar tonsils, histologically, the tissue demonstrated loss of Purkinje cells with concomitant Bergmann gliosis. The ischemic and cystic tissues were virtually the same, histologically. CONCLUSIONS: Based on our findings, cerebellar tonsillar ischemia and cysts in patients with CM-I can often be seen radiologically. Histologically, these ischemic and cystic tissues are the same. Moreover, we document patients where ischemic lesions progressed to cysts, radiologically. Taken together, cerebellar tonsillar ischemia and cysts are on a continuum and represent chronic compression of this herniated part of the cerebellum.

Intraparenchymal cyst development after deep brain stimulator placement.

Following deep brain stimulation (DBS) surgery, a variety of potential mechanical or functional complications ranging from perioperative events to hardware malfunction may occur. We present 2 patients who developed a unique complication of cyst formation at the tip of the DBS electrode in the absence of infection. One patient had a unilateral ventral intermediate lead placement for essential tremor, and the other had bilateral subthalamic nucleus (STN) placement for Parkinson's disease. After a period of symptom control, at 3 and 8 months after surgery, respectively, both patients developed new neurological deficits and were found to have a cyst at the left DBS lead tip. The right lead in the patient with the bilateral STN implant was without issue. Both affected leads were removed and the problematic symptoms regressed quickly over several days, though the lesion effect on the patients' initial tremor symptoms lasted for months. Bacteriological cultures of the removed electrodes and wounds were negative. We report a rare complication of DBS and show that simply removing the involved lead results in cyst resolution.

Prevalence of choroid plexus cysts in term and near-term infants with congenital heart disease.

OBJECTIVE: We retrospectively studied term and near-term infants to determine if there is an increased prevalence of choroid plexus cysts associated with congenital heart disease. MATERIALS AND METHODS: We reviewed 231 consecutive cranial ultrasound examinations from January 2005 through December 2008 on infants between 37-42 weeks of gestation (115 infants with and 116 without congenital heart disease). After exclusion for intracranial hemorrhage or anomalies excluding hydronephrosis, studies on 87 infants with and 99 without congenital heart disease were scored by a single pediatric radiologist blinded to clinical data for the presence of choroid plexus cysts. All studies used a multifrequency 6-8-MHz phased-array transducer. Results were analyzed using Pearson's chi-square test. RESULTS: Of 87 infants with congenital heart disease (53/87 [61%] cyanotic, 34/87 [39%] acyanotic), 26% (23/87) had choroid plexus cysts versus 12% (12/99) without heart disease (χ(2) = 4.48, p < 0.05). The rate of choroid plexus cysts in the cyanotic group (13/54 or 24%) and acyanotic group (10/33 or 30%) (χ(2) = 0.050, p > 0.05) were similar. Among 28 patients who underwent renal ultrasound, 50% (10/20) with congenital heart disease had choroid plexus cysts compared with 12.5% (1/8) of those without (χ(2) = 3.36, p < 0.10). CONCLUSION: We documented an increased prevalence of choroid plexus cysts in infants with congenital heart disease but no difference according to type. Our data revealed a possible association of choroid plexus cysts, hydronephrosis, and congenital heart disease. We suggest ultrasound evaluation of the kidneys and heart in infants with choroid plexus cysts.

The complications of cerebral hydatid cyst surgery in children.

PURPOSE: Complications related to cerebral hydatid cyst surgery are not uncommon but require prompt diagnosis and treatment. The aim of this study is to demonstrate the radiological findings that would indicate complications after cerebral hydatid cyst surgery in children and to report our results. METHOD: The data of 25 pediatric patients who underwent surgery for cerebral hydatid cysts over a 16-year period were analyzed retrospectively. The complications related to surgical technique and cyst location were recorded. Postoperative radiological findings of the patients were documented. RESULTS: Intraoperative cyst rupture occured in three patients. Subdural effusion developed in five patients, porencephalic cyst in four, subdural effusion associated with porencephalic cyst in two, hemorrhage in two, epidural hematoma in one, and pneumocephalus in three patients. Subdural-peritoneal shunt was placed in two patients. Recurrence of cerebral hydatid cyst was observed in only one patient who experienced intraoperative cyst rupture. There was no surgery-related death. CONCLUSIONS: The complications following cerebral hydatid cyst surgery in children are various and usually not fatal. When appropriate surgical procedures are planned and carefully applied, the results will be excellent with no mortality.

Rathke's cleft cysts in children and adolescents: association with female puberty.

There are few pediatric data regarding manifestations and outcomes of Rathke's cleft cysts (RCC). We retrospectively reviewed 13 cases treated at Massachusetts General Hospital over 10 years. Age at presentation was 12-17 years, except for one 7-year-old who presented with sexual precocity. There was a female preponderance [11 females, 2 males, p = 0.01], and all were pubertal at diagnosis. Common features at presentation were headaches (11/13), endocrine abnormalities (5/13) and visual disturbances (2/13). Four patients underwent transsphenoidal surgery. Symptoms improved in all but one, in whom headaches persisted. Recurrent growth in one patient was treated successfully by excision. For conservatively treated patients, cyst size was unchanged over follow-up (6 months-5 years). Female preponderance and pubertal presentation suggest a possible link between sex hormones and RCC pathogenesis. Although estrogen and progesterone receptor immunostaining was negative in the cyst lining, estrogen receptor immunostaining was positive in adjacent pituitary cells. Further investigations regarding this issue are warranted.

Operative intervention for delayed symptomatic radionecrotic masses developing following stereotactic radiosurgery for cerebral arteriovenous malformations--case analysis and literature review.

CASE REPORT: We report two cases of operative intervention that was beneficial in the treatment of delayed symptomatic radionecrotic masses that had developed following stereotactic radiosurgery (SRS) using the gamma knife (GK) for the treatment of cerebral arteriovenous malformations (AVM). DISCUSSION: Case 1 involved a small craniotomy for decompression of a large cerebral multiloculated cyst, which had become symptomatic 84 months following gamma knife treatment for a left frontal lobe AVM. Case 2 involved surgical excision of an occipital radionecrotic mass 72 months following GK treatment for an occipital AVM. This patient had suffered from longstanding symptomatic cerebral oedema, which on occasions had become life threatening. Case 2 is also the first report of a radionecrotic mass occurring post-SRS for an AVM, which conversely appeared to demonstrate increased uptake on single photon emission computed tomography (SPECT) scan. The first literature review of such delayed symptomatic radionecrotic lesions is presented. There appears to be a late onset of symptoms (average 55 months, range 12-111 months) associated with such radionecrosis. Drainage of such cysts or excision of the mass lesion appears to be consistently beneficial to the patients and appears to be uncomplicated. CONCLUSION: We recommend early surgical intervention for such delayed symptomatic radionecrotic masses that do not resolve following non-operative management. We also recommend caution in interpretation of SPECT scan results when attempting to differentiate radionecrosis from neoplasia.

Use of tissue glue to prevent collapse of the cortical mantle during and after cranial surgery in children: a technical note.

INTRODUCTION: Young children with significant ventricular dilatation or large intracranial fluid spaces often have a very thin cortical mantle as a result of persistently raised intracranial pressure. This rim of cortex has a tendency to fall away from the dura into the cavity during and after intracranial surgery, due to the lack of support, once the pressure in the fluid cavity has been reduced. This can lead to tearing of cortical bridging veins and the formation of post-operative subdural haematomas. METHODS: We describe a simple technique that attempts to prevent this phenomenon occurring using tissue glue. Once the craniotomy has been performed and the dura has been formally opened, tissue glue is applied to the underside of the dura around the edge of the wound, prior to corticotomy. RESULTS AND CONCLUSION: This results in the cortical mantle adhering to the undersurface of the dura and prevents the mantle from falling into the cavity either during the procedure or post-operatively.

Endoscopic intervention for intraventricular neurocysticercal cyst: Challenges and outcome analysis from a single institute experience.

OBJECTIVE: Endoscopic intervention is presently proposed as standard approach for the treatment of Intraventricular neurocysticercal cyst (IVNCC) as it helps to retrieve the cyst as well as CSF diversion. We present our series of 61 patients with IVNCC managed by endoscopic intervention and analyze the outcome. METHOD: A retrospective analysis of 61 patients with IVNCC managed between 1998-2019 at our institute was performed. We reviewed the clinical details of consecutive patients, management, and outcome. RESULTS: There were 61 patients with 34 males and 27 females. The mean age was 25 years. Fourth ventricular location is the most common (n = 34) followed by third ventricle(n = 14) and lateral ventricle (n = 13). Cyst retrieval could be done in 43 cases, while the cyst could not be retrieved in 18 cases due to intraventricular bleed, CSF turbidity, adhesion of cyst wall etc. Along with cyst retrieval, some patients underwent Endoscopic Third ventriculostomy, septostomy, foraminotomy for internal CSF diversion. Seven patients had a preoperative VP shunt surgery. The median follow-up was 12 months. Preoperative shunt (CI:1.33-62, P = 0.02) was associated with failure of cyst retrieval in univariate analysis as well as in multivariate regression analysis (CI: 0.02-0.94, P = 0.04). Two patients underwent shunt surgery at follow-up period due to the failure of endoscopic CSF diversion. CONCLUSION: Endoscopic management of IVNCC is a safe and effective management option, avoiding an indwelling shunt system. Endoscopic third ventriculostomy should be considered for patients with IVNCC and hydrocephalus.

Postoperative Cerebellar Cyst with Pseudomeningocele After Tumor Removal at the Craniovertebral Junction.

BACKGROUND: Cerebellar cyst formation after surgery is uncommon, and few cases of this condition have been previously reported. These cases had an intraparenchymal cyst in the cerebellar hemisphere that required surgical fenestration of the cyst. We herein present a rare case of a postoperative cerebellar cyst with pseudomeningocele and magnetic resonance images indicating a fistula between the cyst and pseudomeningocele. CASE DESCRIPTION: A patient presented with an intraparenchymal cyst and surrounding edema in the cerebellar hemisphere that developed after a C1 laminectomy and a small suboccipital craniectomy for the removal of an accessory nerve neurinoma at the craniovertebral junction. Fast imaging employing steady-state acquisition images identified the fistula connecting the cyst and extradural cerebrospinal fluid retention. Conservative management with administration of dexamethasone induced spontaneous regression of the cyst, and no recurrence had occurred by the 1-year follow-up. CONCLUSIONS: Watertight dural closure is important for the prevention of this rare complication after posterior fossa surgery. However, an arachnoid tear on the cerebellar fissure and adjacent dural defect are necessary antecedents for this rare condition. High-resolution fast imaging employing steady-state acquisition images could provide additional information for the etiology of postoperative cerebellar cyst.

Hemorrhagic and Cystic Brain Metastases Are Associated With an Increased Risk of Leptomeningeal Dissemination After Surgical Resection and Adjuvant Stereotactic Radiosurgery.

BACKGROUND: Brain metastases (BM) treated with surgical resection and focal postoperative radiotherapy have been associated with an increased risk of subsequent leptomeningeal dissemination (LMD). BMs with hemorrhagic and/or cystic features contain less solid components and may therefore be at higher risk for tumor spillage during resection. OBJECTIVE: To investigate the association between hemorrhagic and cystic BMs treated with surgical resection and stereotactic radiosurgery and the risk of LMD. METHODS: One hundred thirty-four consecutive patients with a single resected BM treated with adjuvant stereotactic radiosurgery from 2008 to 2016 were identified. Intracranial outcomes including LMD were calculated using the cumulative incidence model with death as a competing risk. Univariable analysis and multivariable analysis were assessed using the Fine & Gray model. Overall survival was analyzed using the Kaplan-Meier method. RESULTS: Median imaging follow-up was 14.2 mo (range 2.5-132 mo). Hemorrhagic and cystic features were present in 46 (34%) and 32 (24%) patients, respectively. The overall 12- and 24-mo cumulative incidence of LMD with death as a competing risk was 11.0 and 22.4%, respectively. On multivariable analysis, hemorrhagic features (hazard ratio [HR] 2.34, P = .015), cystic features (HR 2.34, P = .013), breast histology (HR 3.23, P = .016), and number of brain metastases >1 (HR 2.09, P = .032) were independently associated with increased risk of LMD. CONCLUSION: Hemorrhagic and cystic features were independently associated with increased risk for postoperative LMD. Patients with BMs containing these intralesion features may benefit from alternative treatment strategies to mitigate this risk.

Surgical management of giant craniopharyngiomas.

INTRODUCTION: Multimodal treatment in the management of giant craniopharyngiomas (>4 cm in diameter) is necessary to obtain optimal results, and includes conservative or palliative treatment and "aggressive" removal. The significance of a new treatment algorithm including direct surgical resection with the intent to avoid radiation therapy and regrowth will be discussed here. MATERIALS AND METHODS: Between January 1996 and January 2005 16 patients were diagnosed with giant craniopharyngiomas. Two of them underwent only cyst aspiration because of their advanced age and/or lack of improvement of neuropsychological deficits. One patient underwent transsphenoidal operation and in the remaining 13 transcranial surgery was performed. Four additional patients underwent surgery for recurrence. The prospective protocol included pre- and post-operative dynamic endocrine tests, high field 1.5 T MRI and ophthalmological as well as neuropsychological examinations. RESULTS: In resectable tumours, the rate of total removal was ten out of 12 with two recurrences. In the remaining two patients with recurrences this intention was abandoned because of a firm tumour or a deteriorating neuropsychological status prior to the scheduled additional operation. There was no mortality and the morbidity rate was 6.3%. Visual function improved in 11, was unchanged in one and deteriorated in two patients. Secretion of different adenohypophyseal hormones deteriorated after tumour resection in one to three patients, and new diabetes insipidus occurred in six patients. There was no permanent deterioration of neuropsychological function. CONCLUSION: Special reference is given to direct resection of tumours at an optimal timing within this management. If hypothalamic disturbances are absent or improving due to pre-treatment (medical therapy, symptomatic surgery), giant craniopharyngiomas can be surgically removed in more than two of three patients with low morbidity and only moderate deterioration of endocrine function. The latter has to be accepted when curative surgery is intended, but even then, recurrences cannot be prevented. Contraindication for curative surgery is persisting hypothalamic damage necessitating conservative treatment modalities.

Increased expression of intracystic matrix metalloproteinases in brain tumors: relationship to the pathogenesis of brain tumor-associated cysts and peritumoral edema.

Although several types of brain tumors are commonly associated with cyst formation, the pathogenesis of tumor-associated cysts (TAC) is unknown. We investigated the matrix metalloproteinase (MMP) expression of cyst fluids to elucidate the pathogenesis of TAC in brain tumors. We also examined the relationship between the severity of peritumoral edema and the expression of intracystic MMP. We collected 40 cyst fluid samples from 34 patients with TAC and studied the expression of MMP-2 and -9 in the cyst fluid using gelatin zymography. Radiological studies were used to estimate the severity of the peritumoral edema and to determine the presence of TAC. Although gelatin zymography of the cyst fluid showed high levels of MMPs, there was no correlation between the expression of MMPs in the cyst fluid and that in the tumor tissue. The level of MMP expression in the cyst fluid did not reflect the pathologic grade of the individual tumors. However, the total and activated MMP-9 levels were significantly associated with the severity of the peritumoral edema (p<0.05). These results suggest that MMPs may be partly involved in the pathogenesis of TAC and peritumoral edema in brain tumors.

Craniopharyngioma and Cushing disease: case report.

Craniopharyngioma is a common sellar region tumor occurring in children. It usually manifests as endocrinological deficits such as short stature, delayed puberty, and obesity. Patients with craniopharyngioma commonly present with visual deficits and hydrocephalus. The authors present the case of a child who presented with short stature and clinical evidence of Cushing disease (CD) associated with a suprasellar tumor. The patient underwent insertion of an Ommaya reservoir into the tumor's cystic portion. High adrenocorticotropic hormone (ACTH) levels were demonstrated within the cyst's fluid and in the serum. After adequate decompression of the tumor, the patient underwent total resection. The tumor pathology was compatible with an adamantinomatous craniopharyngioma and immunohistochemical studies failed to show staining for ACTH. Panhypopituitarism developed postoperatively in the patient and he received hormone substitution therapy with final adequate height and normal-high weight. The neurosurgical implications of CD along with a possible mechanism for this patient's presentation are discussed in detail on the basis of the pertinent literature.

Intraparenchymal meningioma.

A 54 year-old woman presented with severe headache. Neuroimaging showed an enhancing intra-axial mass in the right superior temporal region associated with severe peritumoral oedema. Preliminary diagnosis was cerebral metastasis. The mass was surgically removed. Histopathology and immunohistochemistry showed the mass to be an intraparenchymal meningioma, which is rare. The relevant literature is reviewed.

Levodopa-responsive hemiparkinsonism secondary to cystic expansion from a coiled cerebral aneurysm.

An 80-year-old woman with longstanding hemifacial spasm had a 1 cm × 1.5 cm internal carotid artery terminus aneurysm treated with endovascularly delivered bare metal coils. Follow-up imaging revealed an expansile perianeurysmal cyst that coincided with development of contralateral dopa-responsive hemiparkinsonism. This is the first report of perianeurysmal cyst expansion causing levodopa-responsive hemiparkinsonism.

Angiomatous lesion and delayed cyst formation after gamma knife surgery for intracranial meningioma: case report and review of literatures.

Gamma Knife has become a major therapeutic method for intracranial meningiomas, vascular malformations and schwannomas with exact effect. In recent years an increasing number of delayed complications after Gamma Knife surgery have been reported, such as secondary tumors, cystic changes or cyst formation. But angiomatous lesion and delayed cyst formation after Gamma Knife for intracranial lesion has rarely been reported. Here we report the first case of angiomatous lesion and delayed cyst formation following Gamma Knife for intracranial meningioma and discuss its pathogenesis.