Aggressive giant pituitary adenoma presenting as a nasopharyngeal mass: magnetic resonance imaging and pathologic findings

We report a giant pituitary adenoma with aggressive histologic features tha t prominently invaded the nasopharynx. Magnetic resonance imaging (MRI) dem onstrated a large heterogeneous nodular mass that was hypointense to isoint ense on T1-weighted images and mixed hypointense, isointense, and hyperinte nse on T2-weighted images. The mass measured 7.5 x 5 x 7 cm, extending from the nasopharynx posteriorly through the clivus, and superiorly through the paranasal sinuses, and sellar-suprasellar region. After contrast administr ation, heterogeneous nodular enhancement was noted. A nasopharyngeal neopla sm extending into the sella was suspected because voice change and nasal sp eech long preceded the patient's visual symptoms. A biopsy disclosed an agg ressive, infiltrating, hemorrhagic tumor, which was diagnosed as a non-secr eting pituitary macroadenoma. This report indicates that pituitary adenomas may grow invasively to tremendously large sizes resulting in their initial presentation as nasopharyngeal masses.