Intracranial epidermoids--concerning the low absorption value on computerized tomography.

Area of Science:

• Neurology
• Radiology
• Pathology

Background:

• Intracranial epidermoids are benign tumors that can present with varying imaging characteristics.
• Low density on computed tomography (CT) scans in epidermoids can be challenging to interpret.
• Understanding the composition of these tumors is crucial for accurate diagnosis and treatment planning.

Observation:

• Two cases of intracranial epidermoids with low CT density were analyzed.
• Both tumors exhibited similar biochemical compositions, predominantly water and protein, with a small lipid fraction.
• Despite similar compositions, the CT absorption values differed between the two tumors.

Findings:

• Both epidermoids communicated with the cerebrospinal fluid (CSF) space, confirmed by CT scan and surgical aspiration.
• The CT absorption values of the tumors were comparable to or slightly higher than that of CSF.
• No negative lipid values were observed, suggesting lipids were not the primary cause of low attenuation.

Implications:

• The findings suggest that intratumoral CSF, rather than cholesterol content, is the main determinant of low CT attenuation in these epidermoids.
• This understanding can improve the diagnostic accuracy of CT scans for intracranial epidermoids.
• Differentiating epidermoids from other cystic or lipid-rich lesions is critical for appropriate clinical management.