PITUITARY METASTASES - MR FINDINGS

Tumors metastatic to the pituitary gland are uncommon, an they are dif ficult to differentiate radiologically from pituitary adenomas. We ret rospectively reviewed the MR examinations and clinical records of nine patients with radiographic and/or clinical evidence of pituitary meta stases. The most common clinical symptoms included cranial nerve defic its (67%) and/or pituitary dysfunction (30%). Both occurred acutely an d progressed rapidly over 1-4 weeks in all patients. Cranial nerve inv olvement was predominantly multiple (83%), a reflection of involvement of the adjacent cavernous sinus. In contrast to previous reports indi cating a predilection for symptoms related to posterior lobe involveme nt (71%), our study shows that symptoms related to the anterior lobe a re as common as posterior lobe symptoms. Useful MR findings included a relatively small, enhancing pituitary lesion (less-than-or-equal-to 1 .5 cm in 56%) that was relatively isointense to brain on both T1- and T2-weighted images (78%) and involvement of the hypothalamus/pituitary infundibulum (44%) or cavernous sinus (56%).