Clinics in diagnostic imaging (40). Iliotibial band syndrome.

A 51-year-old male cyclist presented with a mass over the lateral portion of his knee. MR scans showed a cystic collection deep to the iliotibial band (ITB). Diagnosis of the ITB syndrome and its differentiation from other cause of painful lateral knee masses, such as meniscal cyst, lateral collateral ligament injury and Segond fracture, are discussed.