Intraparenchymal Cysts Research Articles

Mesencephalic ependymal cysts: treatment under pure endoscopic or endoscope–assisted keyhole conditions

Primary intracranial ependymal cysts are extremely rare. Similar to congenital intraparenchymal cysts in the mesencephalon they usually occur with symptoms of an occlusive hydrocephalus or symptoms like Parinaud syndrome, dizziness, or gait disturbance. The objective of this study was to evaluate the surgical methods for the treatment of these cysts and the clinical outcome of the patients. The authors present the clinical records of 8 patients who were treated in their department for symptomatic mesencephalic ependymal cysts in the past 10 years. The patient age ranged from 22 to 60 years with a mean age of 44 years. In 4 cases the authors performed a suboccipital infratentorial supracerebellar approach by using endoscope-assisted microsurgery. The other 4 patients underwent a pure endoscopic procedure over a frontal bur hole trepanation. Four patients became symptom free, and the remaining 4 improved significantly after a mean follow-up duration of 38.5 months (range 5-119 months). One patient underwent 2 operations: first a ventriculocystostomy and 4 months later endoscopic third ventriculostomy because of recurrent hydrocephalus. In 1 case a second surgery was necessary because of a wound infection. In all of the patients an adequate fenestration of the cyst was achieved. A symptomatic mesencephalic ependymal cyst is an indication for neurosurgical intervention. These cysts can be treated successfully and most likely definitively by a pure endoscopic or endoscope-assisted keyhole neurosurgical technique. There were no morbid conditions or death due to the procedures in this group of 8 patients. Therefore, the authors regard these surgical procedures to be good alternatives to treatments such as shunt placement or stereotactic aspiration of the cysts.

Neuro-endoscopic management of mesencephalic intraparenchymal cyst: a case report

Background Intraparenchymal cyst of the mesencephalon is rare, and its natural course is unclear. The optimal treatment for this entity is still undetermined. Case Description A 54-year-old woman was found to have asymptomatic multilobulated mesencephalic cysts. Two years after the initial diagnosis, she experienced headache and double vision, when MRI showed the enlargement of the multilobulated cystic lesions which markedly compressed the mesencephalon and the aqueduct, resulting in noncommunicating hydrocephalus. She underwent diagnostic endoscopic biopsy and ETV by flexible endoscopic system, which revealed the mesensephalic cyst wall at the dorsal part of the third ventricle floor. A part of the cyst membrane was carefully excised by endoscopic forceps without injuring the surrounding structures. Histopathological examination revealed that the cyst wall was exclusively neuroglial tissue, and the presence of neoplasm was ruled out. Her symptoms were relieved immediately after surgery, and postoperative MRI showed both the shrinkage of mesencephalic cysts and the improvement of hydrocephalus. There is no recurrence of her symptoms, and MRI findings have been stable during the 3 year follow-up period. Conclusion Intraparenchymal cysts of the mesencephalon have an expanding nature. Once those cysts become symptomatic, we recommend endoscopic procedure including decompression and biopsy of the cyst with ETV.

Residual Brain Calcifications in Neurocysticercosis

A 33-year-old female Peruvian patient presented with a 10-year history of secondary generalized seizures. Initial neuroimages showed brain lesions compatible with cysticercosis including an extensive subarachnoid lesion in the right temporo-parietal convexity and multiple intraparenchymal viable cysts and calcifications. She received a course of albendazole (ABZ) at 15 mg/kg/d, stopped at day 15 because of increased liver enzymes that returned to normal values after suspension of ABZ treatment. The subarachnoid lesion markedly decreased in size, and most parenchymal cysts resolved. After 1 year, a ventricle-peritoneal shunt was placed, and a second course of ABZ was needed because of re-growth of the subarachnoid lesion and persistence of four viable parenchymal cysts. All cysts resolved after a second course of anti-parasitic treatment. Neurocysticercosis is a frequent cause of seizures in most of the world. This case illustrates the effect of antiparasitic therapy to kill parasite cysts, the frequent need for successive courses of therapy, and the potential of subarachnoid lesions to grow and cause obstructive hydrocephalus. Even after successful anti-parasitic treatment, the remaining calcified scars persist, acting as foci of relapsing inflammation and seizures.

Quistos neuroepiteliais intra-parenquimatosos: aspectos imagiológicos.

Neuroepithelial cysts, heterogeneous group of lesions, are fluid collections similar to CSF, lined by epithelial cells, frequently found in the lateral ventricles and choroidal fissure; intraparenchymal cysts are relatively uncommon. We report CT and MRI imaging findings of four intraparenchymal neuroepithelial cysts, two of which have histological confirmation of the diagnosis.

Antiparasitic Drug Reduces Some Seizures in Neurocysticercosis with Viable Cysts

These investigators tested whether treatment with an antiparasitic (albendazole) and a corticosteroid (dexamethasone) would reduce seizures associated with neurocysticercosis. They randomized 120 adults with viable intraparenchymal cysts and a recent history of at least one seizure, to receive 10 days of either 800 mg daily albendazole plus 6 mg daily dexamethasone (ALB/DEX) or matching placebos. Participants with cysts surrounded by edema and inflammation were included if MRI documented a liquid center (considered a sign of viability). All patients were cysticercosis-seropositive. All received anticonvulsants (mostly phenytoin) until seizure-free for one year, …

Renal cysts: is attenuation artifactually increased on contrast-enhanced CT images?

To determine if the attenuation values of simple renal cysts are artifactually increased on contrast material-enhanced, clinically acquired spiral computed tomographic (CT) images. Dual-phase renal spiral CT studies (5-mm collimation; pitch, 1.0) were retrospectively analyzed in 24 consecutive patients who had ultrasonographic (US) documentation of simple renal cysts. Forty-eight cysts were identified. The attenuation values of each cyst were measured on nonenhanced, cortical phase, and nephrographic phase images. The size and the location of each cyst in relation to the renal parenchyma were also recorded. The cysts were 0.6-10.8 cm in diameter (mean, 2.6 cm; SD, 2.0). The mean attenuation change in the cysts from nonenhanced to contrast-enhanced images was statistically significant in a comparison of cortical phase and nephrographic phase images (P: <.01): +1.8 HU (SD, 3.8) for cortical phase and +3. 6 HU (SD, 5.6) for nephrographic phase images. Renal cysts 1.0 cm or smaller showed a higher attenuation increase (mean, +4.0 HU for cortical phase and +11.0 HU for nephrographic phase). None of the renal cysts larger than 1.0 cm demonstrated an increase greater than 10 HU (mean, +1.4 HU for cortical phase and +2.3 HU for nephrographic phase). Intraparenchymal cysts showed higher mean attenuation changes than the exophytic cysts. Attenuation values in the renal cysts increased artifactually on contrast-enhanced images, but this pseudoenhancement was not substantial and was less than 10 HU when the cyst was larger than 1. 0 cm in diameter.

Frameless neuronavigation applied to endoscopic neurosurgery.

We retrospectively analyzed the indications, surgical techniques, and applicability of frameless neuronavigation to endoscopic procedures in a heterogeneous group of 15 patients. In 8 patients indications for surgery were cystic lesions, in 3 patients intraventricular tumors, and in 4 patients occlusive hydrocephalus. The mean age was 39 years (range 9-76 years). The follow-up period ranged from 5-24 months (mean 10 months). Frameless neuronavigation was accomplished with the "operating arm system" in 10 cases and with the "optical tracking system" in 5 cases (RADIONICS, Burlington, USA). In all 15 cases, neuronavigation sufficiently provided anatomical orientation, preoperative planning, and intraoperative realization of the approach. The calculated mean calibration error was 2.1 mm. There have been no permanent morbidities and no mortalities related to the use of endoscopes and neuronavigation. In endoscopic neurosurgery, frameless neuronavigation is a useful tool in planning and realizing the approach and improving intraoperative orientation in selected cases. Indications are small or hidden lesions, impaired visual conditions, abnormal anatomy, and narrow ventricles. Endoscopic procedures include fenestration and resection of intraventricular or intraparenchymal cysts, biopsy of intraventricular tumors, and third ventriculostomy in selected cases.

Benign intracerebral cysts with ependymal lining: pathological and radiological features

Cerebral intraparenchymal cysts without communication with the ventricles are very rare. We report four such cases with no relevant past history or evidence of infection, haemorrhage, trauma, tumour or congenital neural tube defect. At operation smooth wailed cysts with an ependymal-type lining were found. To the best of our knowledge, we present the first correlation of their pathological and radiological features (including magnetic resonance imaging). We also review the literature on these cysts.

Hepatic cysts and hyperechogenicities: perinatal assessment and unifying theory on their origin.

The authors report their experience with the perinatal diagnosis of six cases of hepatic cyst and six of liver hyperchogenicities. The in utero diagnosis of hepatic cysts was difficult when the cysts were large or subhepatic. A precise diagnosis was sometimes achieved only after surgery. Small intraparenchymal cysts tended to regress spontaneously. Liver hyperechogenicities were diffuse or localized. They were unrelated to liver infection, tumors, meconium peritonitis or biliary tract anomaly. Both entities could be related to vascular disruption phenomenon (VDP) in which structural anomalies result from damage to normal development of embryonic or fetal vessels with anomalies of perfusion to the developing organs. The consequences of VDP to the liver are variable depending on the time and duration of the phenomenon. Localized infarct or ischemia can fibrose or calcify leading to segmental hyperechogenicities. Necrosis with tissue reabsorption can be the origin of some (sub)hepatic cysts. When such anomalies are detected there should be a careful study of the placentation, and a search for potential associated anomalies should be undertaken.

Large Postnatally Acquired Porencephalic Cysts: Unexpected Developmental Outcomes

To determine the neurodevelopmental outcome for infants with posthemorrhagic intraparenchymal cysts, we reviewed retrospectively clinical, ultrasonographic, and developmental features in 16 affected children. At a mean follow-up age of 33 months, five subjects had normal cognitive outcomes (developmental quotient [DQ] or IQ greater than 83), nine had borderline to mild deficits (DQ or IQ, 52 to 83), but only three had moderate to severe deficits (DQ or IQ less than 52). Spastic cerebral palsy was present in 13 (81%); only one child (6%) had a chronic seizure disorder requiring medication. Cognitively normal children were less likely to have had neonatal seizures (P less than .05) and tended to have more localized cysts. Otherwise, we found no relationship between outcome and neonatal clinical or laboratory findings. Overall, these results suggest that although motor deficits are common in infants with severe intraventricular hemorrhage and porencephalic cysts, cognitive outcomes may be more favorable than has been suspected previously.

MR imaging of CSF-like choroidal fissure and parenchymal cysts of the brain.

The purposes of this study were to delineate the MR characteristics of CSF-like parenchymal or fissural cysts of the brain and to correlate them with the clinical findings. Clinical data and MR images of 34 patients with these abnormalities were reviewed. Pathologic correlation was not available. Two types of cystic lesions were identified and separated by location: medial temporal lobe cysts arising in or near the choroidal fissure (26 patients) and parenchymal or pseudoparenchymal cysts not related to the choroidal fissure (eight patients). The choroidal fissure cysts simulated intraparenchymal cysts on axial images but their extraaxial location was well portrayed on the coronal images. Choroidal fissure cysts had a characteristic spindle shape on sagittal images. The other cysts were found in the temporal lobe (seven patients) or thalamus (one patient) and appeared parenchymal but situated close to the subarachnoid space. These lesions were round or ovoid. There was no abnormal enhancement in 10 patients studied with gadopentetate dimeglumine. Coronal images were most useful, revealing the cysts as focal CSF-intensity lesions expanding the choroidal fissure of the temporal lobe. All the cysts appeared to represent incidental findings that did not correlate with the clinical signs and/or symptoms that prompted the imaging evaluations. The MR characteristics of CSF-like cysts are important to recognize so that they are not confused with other, more serious entities, such as intraaxial cystic tumors, infarctions, or parasitic lesions.

Focal renal masses: magnetic resonance imaging.

Thirty patients with focal renal masses were evaluated on a .12-Tesla resistive magnetic resonance unit using partial saturation and spin echo pulse sequences. A short repetition time (TR = 143 ms) was employed for partial saturation images and a spin echo was present in each case (TE = 10 ms). Additional pulse sequences through regions of interest were also obtained. Fifteen patients had cystic lesions, nine patients had renal cell carcinoma, two had metastatic lesions, one had an angiomyolipoma, and three had focal bacterial infection. Cystic lesions were well circumscribed and demonstrated a range of signal intensities. Small intra-parenchymal cysts were difficult to identify. Renal cell carcinomas demonstrated areas of increased signal using a partial saturation sequence (TR = 143-415 ms, TE = 10 ms). Magnetic resonance imaging accurately detected perinephric extension and vascular invasion in all patients. Metastatic disease to the kidney was uniformly low in signal, in contrast to primary renal cell carcinoma; an angiomyolipoma demonstrated very high signal intensity. Two masses resulting from acute focal bacterial nephritis were uniformly low in signal. One additional case of a more indolent pyelonephritis demonstrated high signal in regions of replacement lipomatosis and low signal in sites of active infection. Magnetic resonance imaging appears to be an accurate way of detecting, identifying, and staging focal renal masses.

Straited muscle cells in the thymus of reptiles and birds: an electron microscopic study.

AbstractStriated muscle cells, the “myoid cells” of light microscopic literature, are consistently found in the thymus of reptiles and birds. Round or elongated myoid cells resemble adult skeletal or cardiac muscle fibers; however, the location of the nucleus, the course of the myofibrils, the arrangement and proportion of the thick and thin filaments, and the morphology and topography of the membranous components of the sarcoplasm are variable. Other myoid cells which contain either primitive myofibrils, irregular bundles of myofilaments associated with primitive Z plaques, or thick and thin filaments alone scattered throughout the cytoplasm, recall the various stages of the development of skeletal and cardiac muscle fibers. In these cells the ribosomes are often, but not always abundant and appear in places arranged in helices and rosettes. It is suggested that a postnatal myogenesis takes place in the thymus. Anomalous muscle cells contain thin filaments almost exclusively. In some of these cells, thin filaments are arranged in I‐segments that appear either independent of each other or interdigitated in pseudosarcomeres. Finally, some myoid cells appear to have degenerated. Desmosomes join myoid cells to reticular cells, to other myoid cells, and to epithelial cells in the walls of intraparenchymal cysts. The origin of the myoid cells from reticular cells is suggested.