Painless arm swelling in a young woman.

Accepted 23 April 1998 The patient was a 39-year-old woman who, after a brisk movement of the head, noticed pain in the cervical region. Twenty hours later she began to have swelling of the left superior limb. She was treated with muscle relaxants and anti-inflammatory agents with little improvement. Twenty days later the painless swelling persisted and she was admitted to the hospital. Physical examination disclosed fullness and increased diameter of the left arm with cyanosis, oedema and dilation of subcutaneous collateral veins. There were no palpable lymph nodes, and the Adson manoeuvre was negative. Chest X-ray did not show abnormalities. Other investigations, including full blood count, sedimentation rate, serum biochemistry, urine analysis, coagulation study, serum electrophoresis, immunoglobulins, complement, C-reactive protein, rheumatoid factor and antinuclear antibodies, were either normal or negative. A venographic study of the left superior limb was performed (figure 1).