Choroid plexus cyst development and growth following ventricular shunting

ManuscriptChoroid plexus cysts are typically incidental, asymptomatic cysts. They have been reported to hemorrhage and grow, causing symptoms of obstruction. However, growth and multiplication has not been reported following ventriculoperitoneal shunting procedures. A 66-year-old woman initially underwent a suboccipital retrosigmoid craniotomy for resection of a large petroclival meningioma. Preoperatively, the patient demonstrated imaging findings consistent with hydrocephalus. After surgery the patient required a ventriculoperitoneal shunt. Two years after the initial shunting procedure, imaging demonstrated significant growth of new bilateral choroid plexus cysts as compared with pre-shunt imaging. Post-shunt imaging also demonstrated evidence of diffuse dural enhancement characteristic of intracranial hypotension. Despite radiographic growth and multiplication of the cysts, the patient was clinically asymptomatic and had a good neurological outcome

Hemorrhagic and nonhemorrhagic Rathke cleft cysts mimicking pituitary apoplexy

Journal ArticleObject. Rathke cleft cysts (RCCs) are infrequently symptomatic, and apoplexy is one of the most unusual presentations. Only a few cases of apoplexy associated with RCCs have been reported, and their clinical, imaging, surgical, and pathological features are poorly understood. In the cases that have been reported, intracystic hemorrhage has been a consistent finding. The authors report 6 cases of RCCs in which the presenting clinical and imaging features indicated pituitary apoplexy, both with and without intracystic hemorrhage. Methods. The authors retrospectively reviewed charts and magnetic resonance (MR) imaging studies obtained in patients who underwent transsphenoidal surgery for RCC. Six patients were identified who presented with symptoms and MR imaging characteristics consistent with pituitary apoplexy but were found intraoperatively to have an RCC. All 6 patients presented with a sudden headache, 2 with visual loss, and 1 with diplopia. Review of the preoperative MR images demonstrated mixed signal intensities in the sellar masses suggestive of a hemorrhagic pituitary tumor. In all patients there was a presumed clinical diagnosis of pituitary tumor apoplexy and an imaging-documented diagnosis of hemorrhagic pituitary tumor. Results. All 6 patients underwent transsphenoidal resection to treat the suspected pituitary apoplexy. Intraoperative and histopathological findings were consistent with the diagnosis of an RCC in all cases. Only 2 cases showed evidence of hemorrhage intraoperatively. In all cases, an intracystic nodule was found within the RCC at surgery, and this intracystic nodule was present on the initial MR imaging when retrospectively reviewed. The imaging characteristics of the intracystic nodules were similar to those of acute hemorrhage seen in cases of pituitary apoplexy. Conclusions. The clinical and imaging features of RCCs appear similar to those of hemorrhagic pituitary tumors, making them often indistinguishable from pituitary apoplexy

Rathke cleft cyst intracystic nodule: a characteristic magnetic resonance imaging finding

Journal ArticleObject. The fluid content of Rathke cleft cysts (RCCs) displays variable appearances on magnetic resonance (MR) images and can appear indistinguishable from other intrasellar or suprasellar cystic lesions. Intracystic nodules associated with individual RCCs have been noted, but to date their significance has not been fully explored. Methods. The authors retrospectively reviewed MR imaging studies obtained in patients harboring intrasellar or suprasellar lesions that were consistent with RCCs to identify the presence and imaging characteristics of intracystic nodules. An intracystic nodule was present in nine (45%) of 20 patients with an RCC. All intracystic nodules were clearly visible and displayed a characteristic low signal intensity on T2-weighted MR images. The nodule was only visualized on T1-weighted images in four cases, in which it exhibited a consistent high signal intensity similar to that of the cyst fluid. The nodules did not enhance following the intravenous administration of a contrast agent. Conclusions. Although it is difficult to differentiate RCCs from other sellar cystic lesions because of the variable signal intensities displayed on MR images, the intensity of the intracystic nodule seems consistent on T1- and T2- weighted images, and the nodule is always clearly visible on T2-weighted images. With a nonenhancing cystic lesion that does not cause significant symptoms in the patient, the identification of an intracystic nodule with a characteristic signal intensity will aid in the diagnosis of RCC and the selection of conservative management

Retained peritoneal shunt tubing causing hematuria

Journal ArticleThis 14-year-old boy with congenital hydrocephalus underwent initial shunt placement shortly after birth. During his first 6 years of life, multiple ventriculoperitoneal (VP) shunt revisions were performed to address seven shunt malfunctions and one shunt infection (Staphylococcus epidermidis). During the last shunt revision, which took place 8 years before the current presentation, it was noted that the distal peritoneal shunt tubing (Peritoneal Catheter, Standard, Barium Impregnated; Medtronic Inc., Minneapolis, MN) had fractured and was coiled in the pelvis. Nevertheless, the tubing was not retrieved at that time

Optic pathway gliomas: a review

Journal ArticleOptic pathway gliomas represent approximately 3-5% of childhood intracranial tumors. They usually occur in children during the first decade of life and are seen in 11-30% of patients with neurofibromatosis Type 1 (NF1). Although these tumors are typically low-grade gliomas, the clinical course and natural history are highly variable, making treatment paradigms difficult. Overall, however, they are often indolent tumors that can be observed over time for progression without initial treatment, especially in patients with NF1. Chemotherapy is the first-line treatment for progressive tumors, and radiation therapy is reserved for patients with progressive disease who are older than 5-7 years. Surgery is reserved for large tumors causing mass effect or hydrocephalus and tumors confined to the orbit or unilateral optic nerve

Cluster evolution in steady-state two-phase flow in porous media

We report numerical studies of the cluster development of two-phase flow in a steady-state environment of porous media. This is done by including biperiodic boundary conditions in a two-dimensional flow simulator. Initial transients of wetting and non-wetting phases that evolve before steady-state has occurred, undergo a cross-over where every initial patterns are broken up. For flow dominated by capillary effects with capillary numbers in order of $10^{-5}$, we find that around a critical saturation of non-wetting fluid the non-wetting clusters of size $s$ have a power-law distribution $n_s \sim s^{-\tau}$ with the exponent $\tau = 1.92 \pm 0.04$ for large clusters. This is a lower value than the result for ordinary percolation. We also present scaling relation and time evolution of the structure and global pressure.Comment: 12 pages, 11 figures. Minor corrections. Accepted for publication in Phys. Rev.