Juxta-articular myxoma of the knee.

Juxta-articular myxoma is a benign lesion usually presenting as a slow-growing, well-circumscribed mass. Occasionally, however, the lesion grows rapidly and is poorly circumscribed, and it is this clinical presentation that arouses suspicion of malignancy. Furthermore, on histology a myxoma can also be confused with a variety of sarcomas. We present a case of juxta-articular myxoma and discuss the possible diagnostic dilemmas involved.