Endocrine Abstracts

Introduction: Metastases to the hypothalamus and pituitary gland account for 1–2% of sella masses. The primary malignancy may be occult at the time of diagnosis and metastatic lesions are often detected incidentally. We present a case of metastatic renal cell carcinoma presenting as a vascular pituitary tumour.

Case history: A 68-year-old lady presented with headaches and diplopia secondary to right abducent nerve palsy. CT Angiography revealed an intrasellar pituitary macroadenoma with no vascular abnormality or aneurysm. Pituitary MRI scan showed an aggressive pituitary tumour. Biochemical investigations suggested a non-functioning macroadenoma. Trans-sphenoidal resection of the pituitary tumour was attempted but was complicated by massive intra-operative haemorrhage. Haemostasis was achieved with difficulty using a muscle patch. Carotid angiography showed an extremely vascular skull base tumour with multiple feeders from both the internal and external carotid arteries and evidence of intratumoral shunting. Repeat pituitary imaging showed a significant increase in the size of the skull base tumour with invasion of the nasopharynx and right cavernous sinus. Histology of the lesion showed a vascular tumour indicative of renal cell carcinoma Subsequent CT imaging confirmed a 5.2 cm tumour arising from left kidney.

Discussion: Metastases to the hypothalamus and pituitary gland occur most commonly with breast cancer in women and lung cancer in men. Patients usually present with diabetes insipidus, anterior pituitary dysfunction, visual field defects and ophthalmoplegia.In the absence of an obvious primary malignancy, the diagnosis may not be obvious preoperatively but features indicating pituitary metastasis include thickening of the pituitary stalk, cavernous sinus invasion and sclerosis of the sella.

Management of these tumours encompasses surgery, radiotherapy, and chemotherapy but the prognosis is universally poor with a mean survival is 6–22 months.