Endocrine Abstracts

It is very rare to have Pituitary metastasis in Renal Cell cancer (RCC). Prevalence of Pituitary metastasis varies from 1-4% in all cancers and about 2.6% in RCC. Most common cancers with pituitary metastasis are breast (33%) and lung (36%). We present a rare case of RCC with pituitary Metastasis presented with severe Hyponatraemia. A 71 years old male with history of renal cell cancer who underwent Right nephrectomy in 2017. He was found to have intrathoracic metastases in 2018 and started on Tivozanib treatment. He was referred with severe hyponatremia (Sodium-120 mmol). His cortisol was low and had central hypothyroidism. MRI head shown a focal metastatic deposit from RCC and pituitary metastasis. His pituitary functions also revealed a pan hypopituitarism picture as below: His hormones are being replaced. Hyponatremia was a combination of corticotroph and thyrotroph deficiency. He underwent Stereotactic radiosurgery for metastatic disease and is under regular follow up of endocrine team.

Conclusion: Severe hyponatremia can also be a manifestation of Pituitary metastasis. This is a rare clinical condition and difficult to diagnose. However, stepwise approach enables the appropriate diagnosis. It is important to check Cortisol and Thyroid function in hyponatremia.