Presentation
Visual symptoms.
Patient Data
The pituitary fossa is enlarged, with remodeling and thinning of the dorsum sellae. Sphenoid sinus appears well aerated.
A large homogenous hyperdense mass arises from the pituitary fossa, measuring approximately 28mm X 24mm X 33mm ( trans, AP, craniocaudal). It results in erosion of the lateral aspect of the dorsum sellae. There is a nipple pointing posteriorly from the left lateral aspect of the mass passing distal to the posterior wall of the dorsum sellae and abutting the left superior cerebellar artery. There is effacement of the suprasellar cistern.
The A1 segment of the left anterior cerebral artery cannot be identified and may be compressed by the mass, with filling of the A2 segment supplied by the right anterior cerebral artery via the anterior communicating artery. Alternatively the left A1 segment may be hypoplastic/absent. No obvious abnormality of the dural venous sinuses. No further lesion. The orbits are grossly normal.
Large sellar/suprasellar mass is of intermediate T1 signal and a little hyperintense in T2 signal and demonstrates moderate enhancement. A more focal area of more intense enhancement is seen posteroinferiorly. The floor of the sella is thinned, and the mass protrudes into sphenoid sinus. Suprasellar extension to, and elevation of, the floor of 3rd ventricle is noted. There are nodular protrusions into left perimesencephalic cistern close to left SCA and basilar trunk, as well as laterally contacting the left amygdala. No hydrocephalus.
Optic chiasm elevated and bowed over superior border. ACAs displaced superiorly with no encasement. There is tumor contacting left cavernous ICA with just under 180 degree involvement. Right cavernous sinus and right cavernous ICA do not appear involved.
Sphenoid sinus septum is left-sided with its superior edge pointing towards left carotid siphon.
Surgical instruments are noted passing through a speculum placed in the nasal cavity towards the sphenoid sinus, with a probe having entered the sphenoid sinus and abutting the junction between planum sphenoidale and the anterior wall of the sella.
The second image has an instrument in the pituitary fossa with air (lucency) seen in the suprasellar and interpeduncular cistern.
Histology
The sections show a moderately cellular pituitary adenoma comprising trabeculae and nests, surrounded by vascularized stroma. The tumor cells have mildly enlarged round nuclei, finely granular chromatin and moderate amounts of eosinophilic cytoplasm. There are no atypical features. No normal anterior pituitary gland tissue is present. In specimen 2, there is respiratory type sinus mucosa and a small amount of minor salivary gland tissue. The tumor cells are positive for FSH, SF-1 and very focally with LH. Immunostains for prolactin, TSH, ACTH and GH are negative. The Ki-67 index is less than 1%.
FINAL DIAGNOSIS: Pituitary tumor: Gonadotroph cell adenoma.
Case Discussion
This case illustrates typical appearances of a large pituitary macroadenoma.