Extensive Intramuscular Venous Malformation in the Lower Extremity
A previously healthy 36-year-old woman was presented with a year history of pain and tightness in the right proximal thigh. She reported that she felt a pain and pressure of the muscles in her right hamstring when she tried to extend the knee joint during yoga exercises. The symptoms lasted while stretching and gradually improved when she rested. On physical examination, there was full strength in all limbs and normal tone. Sensation was also intact. Reflexes were normal throughout, and there were no pathological reflexes. There was significant tenderness over a wide area of the right posterior thigh, especially medial hamstrings and the popliteal fossa. The overlying skin appeared normal without traumatic injury, erythema or warmth. The circumferences of both thighs, measured 10 centimeters (cm) above the knee, were 44.5 cm (right) and 42 cm (left), respectively. Although measurements of both legs, taken 10cm below the knee, were the same length at 34.5 cm, there was a dimpling in the right medial calf area when the patient was standing (). The creatine kinase (CK) level was 75 U/L (normal range 51-246), lactate dehydrogenase (LDH) was 364 IU/L (normal range 263-450) and C-reactive protein (CRP) was 0.117 mg/dl (normal range 0.02-0.3). There was a mild elevation of the erythrocyte sedimentation rate (ESR) at 33 mm/hr (normal range 0-20). Ultrasonography was obtained to verify the state of the muscles and vessels on the leg and it demonstrated dilated intramuscular veins in the right medial thigh and calf, where the dimpling was seen (). Magnetic resonance imaging (MRI) of the leg revealed multiple engorged tortuous venous structures mainly involving hamstrings, the vastus medialis, the soleus, and medial head of the gastrocnemius (). Subsequent angiography and venography were performed to assess whether venous malformation was connected to the arterial system. Angiography and venography showed multiple dilated venous malformations with connection to the normal veins and no connection to the arterial system (). After discussing treatment with the department of cardiothoracic surgery and radiology, we did not perform surgical resection or focal sclerotherapy, due to risk of muscle damage resulting from resection of the deeply penetrated abnormal veins. We also could not perform focal sclerotherapy due to extensive involvement of the venous malformations. We explained sufficiently about the gains and the losses of the surgery and/or sclerotherapy and met with the patient's consent of conservative management. She was encouraged to avoid excessive stretching exercises of the lower extremities and was treated with aspirin 100 mg/day to prevent deep vein thrombosis. At the current follow up, physical and laboratory examination didn't demonstrate any aggravation of the symptoms or venous malformation.