Differentiation of choroid plexus tumors by advanced magnetic resonance spectroscopy

Tumors of Choroid Plexus and Other Ventricular Tumors

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

Atypical choroid plexus papilloma: clinicopathological and neuroradiological features

Background Atypical choroid plexus papilloma (APP) is a rare, newly introduced entity with intermediate characteristics. To date, few reports have revealed the magnetic resonance (MR) findings. Purpose To analyze the clinicopathological and MR features of APP. Material and Methods The clinicopathological data and preoperative MR images of six patients with pathologically proven APP were retrospectively reviewed. The MR features including tumor location, contour, signal intensity, degree of enhancement, intratumoral cysts, and necrosis; and flow voids, borders, peritumoral edema, and associated hydrocephalus were analyzed. Results The APP were located in the ventricle (n = 4) and cerebellopontine angle (CPA, n = 2). Tumor dissemination along the spinal subarachnoid space was found in one patient. The tumors appeared as milt-lobulated (n = 5) or round mass (n = 1), with slightly heterogeneous signals (n = 5) or mixed signals (n = 1) on T1-weighted and T2-weighted images. Heterogeneous and strong enhancement were found in five cases on contrast-enhanced images. Three of four intraventricular tumors had a partly blurred border with ventricle wall. Four tumors had mild to moderate extent of surrounding edema signals. A slight hydrocephalus was seen in four patients. Incomplete capsule was seen in four tumors at surgery. Histopathologically, mild nuclear atypia was seen in all tumors with a mitotic rate of 2-5 per 10 high-power fields. Conclusion APP should be included in the differential diagnosis when an intraventricular or CPA tumor appearing as a multi-lobulated solid mass with slight heterogeneity, heterogeneous strong enhancement, partly blurred borders, mild to moderate peritumoral edema, or slight hydrocephalus are present.

Intra-axial brain tumors

There is a wide variety of intra-axial primary and secondary brain neoplasms. Many of them have characteristic imaging features while other tumors can present in a similar fashion. There are peculiar posttreatment imaging phenomena that can present as intra-axial mass-like lesions (such as pseudoprogression or radiation necrosis), further complicating the diagnosis and clinical follow-up of patients with intracerebral tumors. The purpose of this chapter is to present a general overview of the most common intra-axial brain tumors and peculiar posttreatment changes that are very important in the diagnosis and clinical follow-up of patients with brain tumors.

Choroid Plexus Tumors: Experience of 10 Cases with Special References to Adult Cases

Choroid plexus tumors (CPTs) are rare intraventricular neoplasms accounting for about 0.3–0.6% of all intracranial tumors. This retrospective study on CPTs presents clinico-pathological features and management strategies based on a 20-year single-institutional experience. This series included 10 consecutive patients with pathologically proven CPTs; 5 choroid plexus papillomas (CPPs), 3 atypical CPPs (ACPPs), and 2 choroid plexus carcinomas (CPCs). Their clinical, radiological, and histopathological features as well as management including follow-up studies were reviewed. The patients included five males and five females, aging from 0 years to 61 years with median of 28 years. The affected site was lateral ventricle in two adults and fourth ventricle in eight patients; four children and four adults. The most common symptoms were gait disturbance and memory disturbance. All the patients underwent craniotomy with total, subtotal, and partial removals achieved in 50%, 40%, and 10% of the patients, respectively. The occurrence of the high grade subtypes was 50% in both the adult and pediatric groups. The Ki-67/MIB-1 index increased across the three histological subtypes, from CPP to ACPP and then to CPC. Adjuvant therapy was administered in three patients. The two patients (one adult and one child) with CPC died of whole central nervous system dissemination. At a median of 62-month follow-up, the other eight patients were alive, with only one patient having recurrence and reoperation. The results demonstrate that gross total resection is usually curative for CPP and ACPP, and adjuvant chemoradiotherapy would be required for CPC and incompletely resected ACPP.

Conventional and advanced MRI features of pediatric intracranial tumors: supratentorial tumors

OBJECTIVE. Our objective is to review the imaging characteristics and applications of conventional and advanced neuroimaging techniques of supratentorial intracranial masses in the pediatric population. Specifically, we review astrocytomas, oligodendrogliomas, primary neuroectodermal tumors, dysembryoplastic neuroepithelial tumors, gangliogliomas, arachnoid cysts, and choroid plexus and pineal region masses. CONCLUSION. Advanced imaging methods, such as MR spectroscopy, perfusion MRI, functional MRI, diffusion-tensor imaging, and tractography, help develop a more accurate differential diagnosis and aid in planning tumor treatment.

[Imaging of lateral ventricle tumors]

Lateral ventricular neoplasms are rare, and account for 50% of all intraventricular tumors in adults and 25% in children. Although these neoplasms are easily detected with computed tomography (CT) and magnetic resonance imaging (MRI), both techniques are relatively unspecific in identifying the type of tumor. However, few imaging patterns are specific for a particular pathological process and useful conclusions can be made from the morphological appearance of the lesion, its location and enhancement pattern. The aim of this article was to review and illustrate the CT and MRI findings of a wide spectrum of tumors of the lateral ventricle. We reviewed choroid plexus tumors, meningioma, subependymal giant cell astrocytoma, central neurocytoma, and less frequent lesion such as lymphoma and metastases.

Imaging tumors of the pediatric central nervous system

Primary tumors of the central nervous system (CNS) are the second most common neoplasms in children and the leading cause of death in this patient population. The primary objective of this article is to describe the most common pediatric brain tumors and to offer an overview of their respective imaging features, primarily on magnetic resonance imaging. Precise anatomic characterization is essential for developing an appropriate differential diagnosis. Once equipped with this critical information, physicians should be better able to make firm diagnoses, leading to improved disease management and patient outcomes in the setting of CNS tumors of childhood.

99mTc-sestamibi scan differentiates tumor from other contrast enhancing tissue in choroid plexus tumors

Choroid plexus tumors are rare brain tumors which account for 0.4% to 0.6% among brain tumors. Tumor resection is known to be of large prognostic impact, and re-resection of residual tumors is a part of standard care. However, after multiple resections it can become difficult to differentiate tumor from reactive tissue. 99mTC-sestamibi scans may assist in differentiating neoplastic (99mTC-sestamibi positive) from non-neoplastic tissue (99mTC-sestamibi negative). Previous literature showed sestamibi to be helpful in detecting residual choroid plexus tumors resulting in further resection. Here, we report the first case to show that sestamibi scans can also help with the opposite decision.

MR Spectroscopy: Truly Molecular Imaging; Past, Present and Future

MR spectroscopy involves the examination of molecules in a much more transparent manner than does routine, clinical, conventional MR imaging. Its performance and interpretation goes back to the origins of MR imaging in nuclear magnetic resonance and also points to a future in which functional type techniques such as molecular imaging tell more than simple anatomy, but also the physiology of what is seen when looking at a patient's radiological images. A brief discussion of the past, present, and appreciation of MR spectroscopy as a molecular imaging modality. Several techniques, applications, and controversies aso are discussed in this article.