30th April 2024

A 54-year-old woman with a history of breast cancer presents with widespread bruising, bleeding gums, and blood in her urine.

A 54-year-old woman with a history of breast cancer presents with widespread bruising, bleeding gums, and blood in her urine. She has been undergoing chemotherapy for the last six months.

Investigations:

Platelets: 45 × 10^9/L (150-450)

Haemoglobin: 110 g/L (120-160)

Prothrombin time (PT): Prolonged

Activated Partial Thromboplastin Time (aPTT): Prolonged

D-dimer: Elevated

Which additional investigation is most likely to help with the diagnosis?