Abstract
Pituitary adenoma, a common benign tumor that can invade the clivus or appear ectopically, poses diagnostic challenges. Intravascular lymphoma is extremely rare and frequently underdiagnosed. A case is presented of coexisting pituitary adenoma and clival intravascular large B‑cell lymphoma, highlighting the differential diagnosis of clival infiltrative lesions.
Teaching point: Clival lesions present a wide diagnostic spectrum; when imaging findings are atypical, histopathology remains essential for definitive diagnosis and appropriate treatment.