<p>Abstract</p> <p>Background</p> <p>The diagnosis of deep vein thrombosis of leg is very common in clinical practice. Not infrequently a range of pathologies are diagnosed after excluding a thrombosis, often after a period of anticoagulation.</p> <p>Case presentation</p> <p>This is a report of three patients who presented with a painful swollen leg and were initially treated as a deep vein thrombosis or a baker's cyst, but later diagnosed as a pleomorphic sarcoma, a malignant giant cell tumor of the muscle and a myxoid liposarcoma. A brief review of such similar reports and the relevant literature is presented.</p> <p>Conclusion</p> <p>A painful swollen leg is a common clinical scenario and though rare, tumors must be thought of without any delay, in a duplex negative, low risk deep vein thrombosis situation.</p