Abstract
The American College of Radiology considers ultrasound to be the most appropriate examination for the diagnosis of deep venous thrombosis (DVT).1,2 However, for patients with persistent calf pain, differential diagnoses must be considered. The most common are cellulitis, Baker's cyst, and superficial thrombophlebitis. Less common differential diagnoses include hematoma, muscle or bone tumor (mass lesion), muscle rupture, compartment syndrome, ischemic arterial disease, and a condition known as pyomyositis. Pyomyositis is the formation of a single abscess within the skeletal muscle that affects the large muscle groups such as the thighs and shoulders.3 If left untreated, pyomyositis is a potentially life-threatening infection. Most cases are reported in tropical climates; however, recent cases associated with human immunodeficiency virus (HIV) have been reported in more temperate climates.3-8