Endocrine Abstracts

Pituitary metastases are reportedly uncommon. Here we report two cases illustrating metastases responding to systemic anticancer therapy (SACT). A 49-year-old woman with metastatic renal cell carcinoma treated with combination ipilimumab and nivolumab immunotherapy was referred for hypocortisolaemia (morning cortisol 74 nmol/l). Biochemical screening revealed an adrenocorticotropic hormone of 16ng/l (0-46), thyroid-stimulating-hormone 0.1mU/l (0.55-4.78), free thyroxine 7 pmol/l (10.0-22.0) and prolactin 1400mu/l. Immunotherapy-induced hypophysitis was suspected and treated with hydrocortisone and levothyroxine. There was no visual field defect or symptoms of polyuria/polydipsia. Pituitary imaging demonstrated a 1.5 x 1.6 x 1.3 cm suprasellar lesion initially suspected to be a non-functioning macroadenoma. Follow-up imaging (6 months) showed a reduction in size of the pituitary lesion, which coincided with an interval response of her underlying metastatic disease. Subsequent scans revealed complete resolution of the pituitary lesion. A 72-year-old man was referred following the incidental finding of liver lesions on an abdominopelvic computed tomography scan (CT) undertaken for lower abdominal symptoms. Histopathology was consistent with a neuroendocrine neoplasm (CEA and calcitonin staining). A further staging CT showed a calcified irregular mass in the left thyroid, multiple bone lesions and a pituitary mass. Serum calcitonin was markedly elevated (16149.00ng/l [0.00-8.40]) confirming the diagnosis of medullary thyroid carcinoma. Subsequent pituitary magnetic resonance imaging (MRI) confirmed a 1.8x2.8x2.7 cm suprasellar mass eroding the sphenoid bone (clear of the optic chiasm) which progressively increased in size (2-month period), consistent with pituitary metastases. The patient was clinically eupituitary with normal biochemistry. He underwent palliative radiotherapy to the spine and was commenced on Cabozantinib, which led to a reduction in volume of the suprasellar mass on follow-up MRI scans. Metastases should be considered for pituitary lesions in patients with underlying cancer, despite seemingly being rare. Loco-regional treatments (especially for compressive symptoms) and SACT remain the mainstay of treatment.