19th February 2025

A 79-year-old gentleman with renal cell cancer presents to his GP with bilateral leg pain

A 79-year-old gentleman with renal cell cancer presents to his GP with bilateral leg pain. He has recently had a staging PET-CT which ruled out distant metastatic spread. On questioning, he has also noted a several week history of constipation, polyuria and polydipsia. He denies weakness, although does feel generally more lethargic and fatigued than usual. Neurological examination is normal.

Which investigation is most likely to reveal the underlying diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.