Fibromas arising from the posterior cruciate ligament tendon sheath in the bilateral knee joints: Case report.

Fibroma of tendon sheath in the intra-knee joint is a very rare and benign soft-tissue tumour which has been reported unilaterally in the various aged people. To help distinguish it from other similar kinds of lesions and symptoms including osteoarthritis, we report the oldest case of fibromas arising from the posterior cruciate ligament tendon sheath in the bilateral knee joints within one year of each other confirmed with magnetic resonance imaging (MRI) features, operative findings and histological examination.