Man With Left Knee Mass

Abstract

A 33-year-old man presented to the orthopedics department with a history of left knee pain for 3 months. Vital signs showed a temperature of 36.1°C (97.0℉), pulse rate of 70 beats/min, and blood pressure of 130/81 mm Hg. Physical examination showed there was a mass without obvious tenderness in the upper aspect of the left knee joint, which was tough and obvious in standing position. Ultrasonographic examination showed a mixed echo in the medial muscle layer of the left knee, and color Doppler showed a low-velocity blood flow signal in the mass (Figure 1 and Video).