A case of desmoid tumor-induced external iliac vein compression misidentified as deep vein thrombosis

Desmoid tumor, also known as desmoid-type fibromatosis, is a rare, intermediate, locally aggressive tumor with a high possibility of local infiltration and recurrence, potentially leading to life-threatening problems. We report a case of a 15-year-old girl who visited the emergency department with a 1-week history of the left leg swelling. A point-of-care ultrasound on the leg showed dilated left femoral and popliteal veins. Subsequently, a computed tomography venogram demonstrated a large pelvic mass compressing the left external iliac vein. She underwent tumor resection, and was uneventfully discharged on day 12.