Choroid plexus: normal size criteria on neuroimaging.

PURPOSE: The lack of a well-recognized normal size criterion for the choroid plexus makes small or diffuse choroid plexus pathologies difficult to recognize. The purpose of this study was to determine the normal size of the choroid plexus in the pediatric population utilizing magnetic resonance imaging (MR) and ultrasound (US). As volume measurement across multiple slices is a laborious process, we wanted to propose a simple clinical tool that is easy to use, reproducible, and quick to obtain measurements. METHODS: This study retrospectively evaluated choroid plexus size in 90 children between the ages of 0 and 16. To determine the choroid plexus thickness, a total of 97 studies (71 MRIs and 26 Ultrasounds) were reviewed, from children without any signs of choroid plexus pathology; 6 measurements were taken from MR studies, and 3 measurements were taken from US studies. Averages and ranges of choroid plexus thickness were computed across age groups and gender. RESULTS: Across all ages, the mean choroid plexus thickness in the lateral ventricles was found to be 3.4, 3.3, and 3.1 mm in the axial, coronal, and sagittal views; 3.2 mm in the temporal horns; 2.5 mm in the fourth ventricle with the lateral limb of the choroid plexus in the fourth ventricle measuring 11.3 mm in length. No trends were observed with respect to age subgroups or gender. CONCLUSION: Choroid plexus thickness on average was 3.2 mm in the lateral ventricles and 2.5 mm in the fourth ventricle.

Primary intramedullary spinal cord germinoma.

Primary intramedullary spinal cord germinoma (PISCG) is an exceedingly rare diagnosis, with fewer than 30 cases reported in the literature. It is even less common in the pediatric population. Usually, initial imaging at patient presentation reveals a mass. The authors describe the unique case of a child whose initial imaging showed only focal spinal cord atrophy, which was the earliest sign of a slowly growing intramedullary lesion that was eventually proven via biopsy to represent a PISCG. The authors outline this child's diagnostically challenging presentation, review the events leading up to a diagnosis, briefly discuss PISCG, and summarize their recommendations for other physicians who may encounter a similar case. They assert that PISCG should be considered as a rare entity in the differential diagnosis of progressive spinal cord dysfunction even in the absence of an MRI abnormality of an intrinsic spinal cord mass, especially if there is unexplained focal atrophy of the cord.