Answer for BIR CoW 02 Feb 2025
INTRAVENTRICULAR EPIDERMOID CYST
Findings
Evidence of relatively well defined CSF Dense extra axial cystic lesion noted in Fourth ventricle seen insinuating through bilateral foramen of Luschka. In MRI , Cystic lesion shows diffusion restriction confirming the diagnosis of intraventricular epidermoid Cyst.
Discussion
Intracranial Epidermoid Cyst are uncommon congenital lesions. It is usually very slow growing lesion,typically patients are between 20 and 40 yrs. It is most commonly located in cerebellopontine angle. IMAGING FEATURES: Intracranial Epidermoid cysts appear as lobulated lesions that fill and expand CSF spaces and insinuating between structures and encasing adjacent nerves and vessels. It Follows CSF density /intensity in both CT and MRI. Epidermoid cysts may be hyperdense due to hemorrhage , saponification or high protein content.( white Epidermoids). Epidermoids often indistinguishable from arachnoid cysts, however dirty CSF on FLAIR Sequences and restricted diffusion with low ADC Values useful to differentiate Epidermoid from Arachnoid cyst.( Diffusion restriction not seen in Arachnoid Cyst)
References: Osborn AG, Preece MT. Intracranial cysts: radiologic-pathologic correlation and imaging approach. Radiology. 2006;239 (3): 650-64. Radiology (full text) - doi:10.1148/radiol.2393050823 - Pubmed citation.
Findings
Evidence of relatively well defined CSF Dense extra axial cystic lesion noted in Fourth ventricle seen insinuating through bilateral foramen of Luschka. In MRI , Cystic lesion shows diffusion restriction confirming the diagnosis of intraventricular epidermoid Cyst.
Discussion
Intracranial Epidermoid Cyst are uncommon congenital lesions. It is usually very slow growing lesion,typically patients are between 20 and 40 yrs. It is most commonly located in cerebellopontine angle. IMAGING FEATURES: Intracranial Epidermoid cysts appear as lobulated lesions that fill and expand CSF spaces and insinuating between structures and encasing adjacent nerves and vessels. It Follows CSF density /intensity in both CT and MRI. Epidermoid cysts may be hyperdense due to hemorrhage , saponification or high protein content.( white Epidermoids). Epidermoids often indistinguishable from arachnoid cysts, however dirty CSF on FLAIR Sequences and restricted diffusion with low ADC Values useful to differentiate Epidermoid from Arachnoid cyst.( Diffusion restriction not seen in Arachnoid Cyst)
References: Osborn AG, Preece MT. Intracranial cysts: radiologic-pathologic correlation and imaging approach. Radiology. 2006;239 (3): 650-64. Radiology (full text) - doi:10.1148/radiol.2393050823 - Pubmed citation.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!