Macrocerebellum in Achondroplasia: A Further CNS Manifestation of FGFR3 Mutations?

Achondroplasia is the result of a mutation in the fibroblast growth factor receptor 3 gene (FGFR3). Appearances suggestive of macrocerebellum have not been described in this patient group. We retrospectively reviewed MR imaging studies of the brain in 23 children with achondroplasia. A constellation of imaging findings that are recognized in macrocerebellum was observed, including cerebellar hemisphere enlargement (inferior and superior extension, wrapping around the brainstem); an effaced retro- and infravermian cerebellar subarachnoid CSF space; a shortened midbrain; distortion of the tectal plate; and mass effect on the brainstem. All MR imaging studies exhibited some of these findings. Quantitative analysis confirmed an increased cerebellar volume compared with age- and sex-matched controls. We hypothesized that this may be due to direct effects of the FGFR3 mutation on cerebellar morphogenesis.

Age-related pituitary volumes in prepubertal children with normal endocrine function: volumetric magnetic resonance data.

BACKGROUND: Evaluation of the size of the pituitary gland on magnetic resonance imaging (MRI) may be difficult, considering the wide variation in normal gland morphology. Given the paucity of age-related biometric data, our purpose was to obtain standard normal reference values for pituitary volumes in prepubertal children using three-dimensional MRI data. METHODS: Children under the age of 10 yr undergoing brain MRI for seizures or idiopathic developmental delay and who had no endocrine abnormality were recruited prospectively over 2 yr. All MRI studies included a three-dimensional sequence. Only subjects with normal studies were included. One hundred thirty-nine children were eligible (mean age, 5.2 yr). Direct pituitary volumes were measured from contiguous 1-mm thick reconstructed coronal and sagittal images. Estimated pituitary volumes were calculated using pituitary height, width, and length. RESULTS: Volumes obtained from reconstructions in either plane were essentially identical. There was a linear increase in log-transformed pituitary volume with age, but relatively weak correlations with height or body mass index. There was no gender difference and only weak correlations between pituitary height and pituitary volume and between estimated pituitary volume calculation and measured pituitary volume. We provide age-related reference ranges for pituitary volumes in graphical and tabular forms.

Neonatal nasopharyngeal teratomas: cross sectional imaging features.

BACKGROUND: Neonatal nasopharyngeal teratomas are extremely rare and there are few reports describing both CT and MRI features of these lesions. OBJECTIVE: To describe the CT and MRI appearances of neonatal nasopharyngeal teratoma. MATERIALS AND METHODS: Three neonates with nasopharyngeal teratomas and severe respiratory distress were reviewed. RESULTS: The nasopharyngeal mass resulted in severe respiratory compromise requiring urgent intervention. Characteristic mandibular and pterygoid plate abnormalities demonstrated by CT and MRI are described. CONCLUSIONS: Prenatal MRI enables the diagnosis, delineates tumour extent and allows planned delivery. CT and MRI play a key role in differentiating neonatal nasopharyngeal teratomas from other causes of a neonatal neck mass, thus optimising management.