Pituitary macroadenoma

Case contributed by Bruno Di Muzio
Diagnosis almost certain

Presentation

Patient presenting with a bitemporal hemianopsia

Patient Data

Age: 75 years
Gender: Male

MRI Pituitary gland

mri

The pituitary fossa is expanded, measuring 14 mm in anterior to posterior diameter, filled by a bilobed hypoenhancing tumor which has overall dimensions of 13 x 19 x 14 mm; the smaller suprasellar component measures 8 x 9 x 10 mm, and severely distorts the optic chiasm particularly slightly to the right of the midline. The infundibulum is displaced posteriorly into the right. On both sides the tumor bulges into the cavernous sinuses, contacting each carotid artery over approximately 150 degrees, without convincing invasion. The diaphragma sella is elevated, with an aperture of approximately 10 mm. The sphenoid sinus posteriorly is divided by a septum which is near the midline, slightly deviated towards the right; anteriorly the septum swings out towards the left.

The remainder of the imaged brain (please note this study has been targeted to the pituitary, and as such the whole brain has not been imaged) appears unremarkable.

Conclusion: Pituitary tumor almost certainly represents a macroadenoma.

CTB & Paranasal sinuses

ct

Noncontrast axial images have been obtained prior to planned transphenoidal pituitary surgery. Outside images unavailable for direct comparison.

A right-sided suprasellar mass has a broad contact with the heavily calcified right supraclinoid internal carotid artery.

The nasal septum is midline. A small amount of mucosal swelling shown in the right ethmoid sinus, and even less in the maxillary sinuses. The ostiomeatal complexes are patent and normal.

Supraorbital Haller cells noted.

A large pterygoid recess is shown in the left sphenoid sinus, anteriorly the bony septum lies to the right of the midline-posteriorly two bony septa are shown, the floor of the sella appears intact.

Annotated image

Annotated image demonstrating the indentation at the diaphragma sellae that gives a snowman or figure eight configuration to the macroadenoma. 

Case Discussion

Pituitary macroadenomas are the most common suprasellar mass in adults, and responsible for the majority of transsphenoidal hypophysectomy.

On imaging they usually present as a solid tumor with an attenuation similar to brain (30-40 HU) and demonstrates moderate contrast enhancement. The same is observed on MRI, where they are isointense to the grey matter both on T1 and T2-weighted images. However attenuation and signal characteristics can significantly vary depending on tumor components such as hemorrhage, cystic transformation or necrosis.

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