Fig. 1

Preoperative sagittal (A) and coronal (B) planes of magnetic resonance imaging (MRI) revealed a pituitary macroadenoma 2.5 cm*2.0 cm that invaded the right cavernous sinus and encased the right internal carotid artery (ICA) completely (Knosp grade 4). (C) and (D) Three months after the first transsphenoidal surgery (TSS), MRI indicated that the tumor was gross totally resected. (E) and (F) Before the first frontal craniotomy, MRI in October 2011 revealed a rapidly enlarged tumor with compression of the optic chiasm. (G) and (H) After the first frontal craniotomy, MRI demonstrated that the tumor was subtotally removed. (I) and (J) Before the second craniotomy, MRI in March 2012 indicated a rapidly growing tumor with compression of the optic chiasm and invasion into the third ventricle. (K) and (L) After the second frontal craniotomy, the tumor was subtotal resected