Simple Care Home Health

An 81-year-old man with hypertension presented to the emergency department with pain and swelling of the left thigh and lower leg that had developed during the previous several hours. He had no history of recent surgery or trauma and no known personal or family history of clotting disorders. The left lower leg was tender, cold, and swollen (Panel A), and the left dorsalis pedis pulse was not palpable. What’s the diagnosis?