A 21-year-old female patient with no medical history pre senting with an occasional diplopia affecting the right eye as sociated with headaches, without nausea and vomiting.

Physical examination revealed a slight adduction limitation of the right eye, with no significant ptosis. The initial diagnosis was partial third cranial nerve palsy.

A Computed Tomography (CT) scan revealed well-defined interpeduncular cistern mass, located right of midline, with fat density, was approximately 10x4x8mm in size (Figure 1-3).

Intracranial lipomas are foci of adipose tissue found within the intracranial cavity and Cerebrospinal Fluid (CSF) cisterns, resulting from an embryonic differentiation anomaly of the me ninx primitiva. Most intracranial lipomas remain asymptomatic and are typically identified incidentally during imaging studies. Pericallosal location is the most frequent, however lipomas of the interpeduncular cistern are very rare [1].

On CT scan, intracranial lipomas appear as lobulated masses with fat density, respecting adjacent structures, without en hancement after injection. On MRI, they appear as hyperintense masses on T1W and T2W images, while they are hypointense on fat suppressed images. In some cases, peripheral calcifica tion may accompany these lesions. A biopsy is unnecessary, as the characteristic findings of intracranial lipomas on CT and MRI are sufficient for diagnosis [1].

In this case, due to the lipoma’s small size, mild symptoms, and critical anatomical location, a conservative management approach was chosen.