Challenging case: A rare vascular anomaly masquerades as a basketball injury

FAVA fibroadipose vascular anomaly challenging case MRI axialA 13-year-old male presented to Boston Children’s Hospital Sports Medicine Division with complaints of right distal thigh and knee pain. He awoke the morning after a basketball game with significant discomfort and was unable to walk, suggesting an injury sustained during the game. A physical exam revealed exquisite tenderness of the distal quadriceps muscles, and the patient was unable to adequately fire his quadriceps muscle or extend his knee. Radiographs were normal.

The sports medicine physician referred the patient to Boston Children’s Radiology Department for an MRI of the knee to evaluate the quadriceps tendon. The same-day exam was performed at Boston Children’s ambulatory MRI.

FAVA fibroadipose vascular anomaly challenging case MRI sagittalFAVA DCE-MRAInitial sequences through the knee revealed an obvious lesion in the quadriceps muscles. The lesion extended off of the superior aspect of the images and could not be completely assessed within the field of view.

After repositioning the patient and using a larger coil capable of imaging the entire femur, the radiologist determined that the lesion extended the entire length of the vastus intermedius muscle. Given strong concerns for a vascular anomaly, a dynamic contrast-enhanced MR angiogram was performed.

Based on the MRI findings, the patient was diagnosed with a fibroadipose vascular anomaly (FAVA), a rare vascular tumor of muscle, and referred to Boston Children’s Vascular Anomalies Center.  He was evaluated by a multidisciplinary team consisting of surgeons, hematologists and an interventional radiologist, and will undergo sclerotherapy of the lesion, in addition to medical management for thrombophlebitis.