Intracranial Lipoma
An intracranial lipoma is a rare, benign collection of mature fatty tissue located within the skull. These lesions are believed to develop during early fetal brain formation rather than representing true tumors. Most intracranial lipomas cause no symptoms and are discovered incidentally during brain imaging performed for unrelated reasons. In some cases, however, they may be associated with developmental brain abnormalities or, less commonly, neurological symptoms depending on their size and location.
What is it?
Intracranial lipomas are congenital lesions thought to arise from abnormal development of embryonic tissues that normally form the membranes and fluid spaces surrounding the brain. Instead of regressing during development, these tissues persist and differentiate into mature fat.
These lesions most commonly occur near the midline of the brain, particularly around the corpus callosum, although they may also appear in regions such as the suprasellar cistern, quadrigeminal cistern, or cerebellopontine angle. Some intracranial lipomas, especially those associated with the corpus callosum, may occur alongside developmental brain abnormalities.
MRI is the preferred imaging test for evaluating intracranial lipomas because fat produces a highly characteristic appearance on MRI sequences, often allowing confident diagnosis without invasive testing. CT imaging can also be helpful because fat appears as a very low-density area on CT scans. The distinctive imaging characteristics usually enable radiologists to differentiate intracranial lipomas from other intracranial masses with high accuracy.
Important to Know
Most intracranial lipomas are benign, stable lesions that do not require treatment. They often remain unchanged over many years and are commonly managed with observation alone. Surgical removal is rarely performed because these lesions are frequently located near important blood vessels and brain structures, increasing surgical risk.
Follow-up imaging may occasionally be recommended, particularly if associated developmental abnormalities are present or symptoms change over time.
Red flag symptoms include sudden severe headache, seizures, new or worsening neurological symptoms, vision changes, or loss of consciousness. These symptoms require prompt medical evaluation and may reflect another neurological condition rather than the lipoma itself.