The diaphragma sellae meningioma -- a rare differential diagnosis of non-functioning pituitary adenoma

It is important to differentiate the rare Diaphragma sellae meningioma from the quite common hormonally inactive pituitary adenoma, especially with regards to the surgical approach. The differentiation could, however, be problematic. We report the case of a 66-year-old woman with a Diaphragma sellae meningioma, which became apparent through a visual field and visual acuity disorder. Successful radical tumor extirpation was achieved via the transsphenoidal approach, since the space-occupying lesion was initially thought to be a hormonally inactive pituitary macroadenoma. However, histological investigation confirmed a meningioma. A careful retrospective analysis of the MRI revealed the possibility of a meningioma having been overlooked, since not all distinguishing features of this lesion were manifested. These criteria, as well as the principles of the surgical approach for treating sellar space-occupying lesions are discussed.