Suprasellar meningioma with intrasellar extension simulating pituitary adenoma. Case report

Dorsum sellae meningioma mimicking pituitary macroadenoma: case report

BACKGROUND

A dorsum sellae meningioma is a rare occurrence. It is difficult to evaluate dorsum sellae meningiomas preoperatively from the viewpoint of neuroimaging. We report a rare case of dorsum sellae meningioma mimicking pituitary macroadenoma in a 73-year-old woman.

CASE PRESENTATION

The patient presented with bitemporal hemianopsia and panhypopituitarism. Magnetic resonance imaging demonstrated a bright, homogeneously enhancing intra- and suprasellar mass and a hypointense region in this mass, which was interpreted as a dorsum sellae. Transsphenoidal extirpation was used because of a suspicion of nonsecreting pituitary macroadenoma. Histopathologically, the tumor was diagnosed as a meningioma. Superselective external carotid angiography before the second surgery revealed that the mass was supplied by the left accessory middle meningeal artery and appeared to originate from dorsum sellae. After preoperative embolization, the patient developed hyponatremia. The tumor was subtotally removed via a transcranial route, and the attachment to the dorsum sellae was coagulated extensively. She did well after a second surgical procedure.

CONCLUSION

These radiologic findings may be useful in differentiating dorsum sellae meningioma from pituitary macroadenoma.

Endosellar meningiomas: report of 2 cases and review of the literature

Two cases of endosellar meningiomas are presented. The clinical and radiological picture is not always sufficiently specific to distinguish meningiomas from other types of sellar lesions, but pre-operative diagnosis is of fundamental importance in choosing the best surgical approach. In both cases, the transsphenoidal approach was used, and due to the dense consistency of the tumors, only biopsies were performed. One of the two patients was reoperated on using the sub-frontal approach for radical removal of the tumor. In the authors' experience, craniotomy proved to be the more favorable approach than the transsphenoidal route for radical excision of endosellar meningiomas. Literature on the classification of sellar meningiomas for radiological diagnosis and surgical strategy of endosellar meningiomas is reviewed.

Magnetic resonance imaging of tuberculum sellae meningiomas: preventing preoperative misdiagnosis as pituitary macroadenoma

Despite recent advances in neurodiagnostic imaging, it may be difficult to differentiate tuberculum sellae meningiomas from pituitary macroadenomas preoperatively. Magnetic resonance (MR) imaging has supplanted computed tomography as the imaging modality of choice for sellar and parasellar lesions, but unenhanced MR imaging does not reliably distinguish between all tuberculum sellae meningiomas and pituitary macroadenomas. Accurate differentiation between these alternative diagnoses of a suprasellar mass is important because a tuberculum sellae meningioma always requires a craniotomy, whereas a transsphenoidal route is preferred for removing most pituitary macroadenomas. The gadolinium-enhanced MR images of seven patients with tuberculum sellae meningioma and seven with pituitary macroadenoma were reviewed retrospectively. Although no specific radiological feature was pathognomonic, a combination of several features allowed the correct diagnosis in all cases. Three characteristics of tuberculum sellae meningiomas distinguish them from pituitary macroadenomas: 1) bright homogeneous enhancement with gadolinium, as opposed to heterogeneous, relatively poor enhancement; 2) a suprasellar rather than a sellar epicenter of tumor; and 3) tapered extension of an intracranial dural base. Each of these findings can be subtle, but careful examination of gadolinium-enhanced, high-quality, thin section coronal and sagittal MR images of the parasellar region for this constellation of findings will allow the correct preoperative diagnosis in patients with either of these tumors.