Aggressive pituitary macroadenoma: CT and MR appearances.

Two cases of aggressive pituitary macroadenoma (prolactinoma) with diffuse invasion of the skull base are described. Clinical signs usually appear late. CT shows the bone destruction, whereas MRI accurately delineates the extension of the tumor and involvement of the surrounding neurovascular structures. Histopathology and immunohistochemical staining are necessary for a definitive diagnosis differentiating prolactimonas from a wide range of skull base tumours and for deciding on additional therapy and prognosis. Aggressive pituitary macroadenoma is a large and diffuse tumor which is difficult to treat; therapy usually consists of extensive surgery, radiotherapy and pharmacotherapy with dopaminergic agents.