Radiologic case study. Gouty tophus involving the distal quadriceps tendon.

This case depicts an unusual presentation of gout, which could be mistaken for sarcoma. The radiographic and MRI findings suggest gout whereas the CT appearance is most specific. Therefore, CT should be considered when MRI demonstrates low to intermediate T2 signal in a heterogeneously enhancing soft-tissue mass around a joint, tendon, or bursa, especially when radiographs show adjacent erosion with a sclerotic margin. Gouty tophus is not excluded by a normal serum uric acid level. Computed tomography or ultrasound can be used to guide needle biopsy to provide diagnostic tissue.