20th June 2023

A 73-year-old woman with a prior history of breast cancer presents to the emergency department with back pain

A 73-year-old woman with a prior history of breast cancer presents to the emergency department with back pain, and a CT chest/abdomen/pelvis demonstrates widespread bone metastases and multiple tiny pulmonary nodules consistent with metastases. She is otherwise fit and well, a lifelong non-smoker, drinks minimal alcohol and takes letrozole only. On examination of her hands, she has soft tissue swelling of all the distal phalanges bilaterally, with resultant loss of the nail bed angle.

What is the most likely underlying pathophysiology of these changes?

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