A 68 year-old lady, transferred from a peripheral hospital with a 3-week history of lethargy, headaches, visual disturbance, retro-orbital pain, nausea, and vomiting. MRI brain had revealed a large pituitary mass suggestive of a pituitary adenoma.
Her past history was significant for a melanoma resected from the back 1 year ago with a 2cm margin. A recent CT chest was suspicious for a right lung upper lobe lesion.
There was no ophthalmoplegia and formal visual field testing showed minor deficits.
The initial pituitary profile revealed deficiencies of cortisol and thyroid axis. She was started on replacement doses of thyroxine and hydrocortisone.
Given the history of prior melanoma, possibility of pituitary metastasis was considered. PET scan revealed multiple hypermetabolic lesions in bilateral lungs and a moderate sized area of avid uptake in the pituitary fossa.
MRI of the pituitary revealed a pituitary mass measuring 15 ×12 mm, abutting the optic chiasm and extending into the cavernous sinus, with no other lesions in the brain.
The patient developed diabetes insipidus, 7 days post admission requiring intranasal Desmopressin.
The biopsy from the original melanoma tumor was negative for bRAF mutation, making the patient ineligible for targeted therapy.
Transphenoidal surgery / biopsy of the pituitary mass was considered as the treating oncology team favoured resection to enable better treatment options, but following multi-disciplinary team consultation it was decided against in view of likely metastatic disease.
She developed progressive metastatic disease involving the brain despite cranial irradiation post discharge.
The repeat MRI brain revealed stable pituitary lesion and a possible new metastasis to the right with reduction in headaches. The lung lesions were stable with no new systemic metastasis on the repeat CT scan.
It was decided to proceed with immunotherapy, if patient responded.
However, patient rapidly deteriorated and succumbed.