Widespread invasion of a giant prolactinoma via valveless venous channels: illustrative case

To the authors' knowledge, this is the first documented case illustrating extensive venous-mediated spread of a pituitary adenoma through valveless venous networks involving the CS, orbital, and clival regions, and it provides a plausible mechanism for the enhanced invasive nature of prolactin-secreting tumors. This case underscores the need for thorough imaging and endocrine evaluation before considering the surgical management of suspected invasive pituitary lesions. https://thejns.org/doi/10.3171/CASE25891.