What additional testing is needed to evaluate a pituitary adenoma?
Ideally, a high-resolution, gadolinium-enhanced, pituitary-dedicated magnetic resonance imaging (MRI) should be performed to characterize the pituitary lesion and its proximity to adjacent structures. Conversely, a contrast-enhanced computed tomography can be performed if a MRI is contraindicated (i.e., corporal metal, pacemakers). Compared with the normal pituitary gland, pituitary macroadenomas are characteristically hypo-enhancing lesions on contrast-enhanced T1 MRI imaging. It is also worth noting that normal pituitary hyperplasia, as from severe hypothyroidism or pregnancy, can present as a “pseudotumor,” which is characteristically homogenously enhancing and uniformly isointense on T1 imaging.
Visual field testing is recommended for pituitary tumors that abut or distort the optic chiasm. Ideally, these patients should be referred to a neuro-ophthalmologist for assessment of visual acuity and visual fields. In addition, optical coherence tomography evaluation may be used as a general tool to assess visual loss and predict recovery.