Case Of the Week (COW) 22 November 2015
Nasal Meningocele
Findings
Coronal CT of PNS shows a defect in the cribriform plate with soft tissue density in right nasal cavity.
Discussion
Meningocele & Cephaloceles are congenital herniations of intracranial contents through a cranial defect. When the herniation contains only meninges, it is designated a cranial meningocele. If the herniation also contains brain, it is called a meningoencephalocele. Meningoceles are classified by the site of the cranial defect through which the meninges protrude. Sincipital Meningoceles Sincipital meningoceles are meningoceles situated in the anterior part of the skull. These include both interfrontal meningoceles and frontoethmoidal meningoceles. Sincipital meningoceles always present as external masses along the nose, orbital margin, or forehead. Interfrontal Meningocele The interfrontal meningocele presents anteriorly as a midline mass situated above the frontonasal suture. In this form, the cranial defect lies between the two frontal bones. Frontoethmoidal meningoceles Frontoethmoidal meningoceles are defined as meningoceles that pass outward from the skull through a defect at the junction of the frontal and ethmoid bones, immediately anterior to the crista galli. Frontoethmoidal meningoceles are then subclassified into nasofrontal, nasoethmoidal and nasoorbital subtypes by the point at which the skull defect and hernia emerge externally. Frontonasal subtype In the frontonasal form of frontoethmoidal meningocele, the meningocele emerges from the bony canal between the frontal and nasal bones.
DDX NASAL HETEROTOPIAS (GLIOMAS) Nasal gliomas are congenital masses of glial tissue that occur intranasally and/or extranasally at or near the root of the nose. They may or may not be connected to the brain by a pedicle of glial tissue. By definition, they do not contain any CSF-filled space that is connected with either the ventricles or the subarachnoid space of the head.
DDX DERMOID CYST WITH INTRACRANIAL EXTENSION An uncomplicated dermoid cyst appears as a well-defined lucency/signal with a sharply marginated capsule.
DDX ETHMOIDAL POLYPS These originate from ethmoidal mucosa and never extend into the cranial fossa.
Contributed By:
Prof. Babu Peter, Dr. P. Karthik, Dr. P. Goutham
Barnard Institute of Radiology
Nasal Meningocele
Findings
Coronal CT of PNS shows a defect in the cribriform plate with soft tissue density in right nasal cavity.
Discussion
Meningocele & Cephaloceles are congenital herniations of intracranial contents through a cranial defect. When the herniation contains only meninges, it is designated a cranial meningocele. If the herniation also contains brain, it is called a meningoencephalocele. Meningoceles are classified by the site of the cranial defect through which the meninges protrude. Sincipital Meningoceles Sincipital meningoceles are meningoceles situated in the anterior part of the skull. These include both interfrontal meningoceles and frontoethmoidal meningoceles. Sincipital meningoceles always present as external masses along the nose, orbital margin, or forehead. Interfrontal Meningocele The interfrontal meningocele presents anteriorly as a midline mass situated above the frontonasal suture. In this form, the cranial defect lies between the two frontal bones. Frontoethmoidal meningoceles Frontoethmoidal meningoceles are defined as meningoceles that pass outward from the skull through a defect at the junction of the frontal and ethmoid bones, immediately anterior to the crista galli. Frontoethmoidal meningoceles are then subclassified into nasofrontal, nasoethmoidal and nasoorbital subtypes by the point at which the skull defect and hernia emerge externally. Frontonasal subtype In the frontonasal form of frontoethmoidal meningocele, the meningocele emerges from the bony canal between the frontal and nasal bones.
DDX NASAL HETEROTOPIAS (GLIOMAS) Nasal gliomas are congenital masses of glial tissue that occur intranasally and/or extranasally at or near the root of the nose. They may or may not be connected to the brain by a pedicle of glial tissue. By definition, they do not contain any CSF-filled space that is connected with either the ventricles or the subarachnoid space of the head.
DDX DERMOID CYST WITH INTRACRANIAL EXTENSION An uncomplicated dermoid cyst appears as a well-defined lucency/signal with a sharply marginated capsule.
DDX ETHMOIDAL POLYPS These originate from ethmoidal mucosa and never extend into the cranial fossa.
Contributed By:
Prof. Babu Peter, Dr. P. Karthik, Dr. P. Goutham
Barnard Institute of Radiology