Chondroid chordoma of the sella turcica mimicking a pituitary adenoma.

We report an unusual case of a chondroid chordoma of the sella turcica that mimicked the clinical and radiologic presentation of the more common pituitary adenoma. A 50-year-old man presented with bitemporal visual field deficits. Magnetic resonance imaging (MRI) detected a sellar mass that was suggestive of a pituitary adenoma. However, the intraoperative appearance of the mass was not consistent with an adenoma, and frozen-section pathology was obtained. Pathology identified the mass as a malignant lesion. Based on this finding, the mass was treated more aggressively. Chondroid chordomas are rare and slowly growing but locally aggressive tumors. The prognosis depends on the ability to totally resect the mass, so differentiating this tumor from a benign lesion is critical. An intrasellar chordoma can be confused clinically and radiologically with a pituitary adenoma. These two lesions are nearly identical on MRI, although T2-weighted imaging sometimes demonstrates higher intensity with a chondroid chordoma. Computed tomography may be helpful in demonstrating bony destruction by these lesions, as can the presence of intralesional calcifications. Intraoperative findings of bony invasion or a purple-red color may also lead the surgeon to suspect a diagnosis other than pituitary adenoma.