Figure 5.

Prolactin-releasing pituitary neuroendocrine tumor in a 16-year-old boy presenting with headaches. Brain MRI including axial (A) T1WI as well as axial (B) and coronal (C) T2WI shows an expansile sellar and suprasellar lesion resembling a “snowman” appearance that cannot be differentiated from the pituitary gland, mainly isointense in T1WI and iso-hyperintense on T2WI (white arrowhead), and with a round hypointense T1 and hyperintense T2 cystic component (black arrowhead) located in the right anterior region and causing displacement of the right rectus and orbital gyri without associated edema. No associated paramagnetic foci suggestive of calcifications are depicted on axial (E) T2 gradient-echo imaging. Coronal (F) and sagittal (G) T1WI after gadolinium injection reveal homogenous enhancement of the solid component of the lesion (empty white arrowhead). There are no signs of cavernous sinus invasion, more prominent on the right (white arrows), without stenosis of the cavernous segments of the internal carotid arteries (asterisks). Note that the pre-chiasmatic segment of the right optic nerve is encased by the lesion [long white arrow in (F)], with significant adherence confirmed intraoperatively. Carotid arteries are marked with asterisks in (F).