Epiphyseal pseudotumor of the tibia:an uncommon presentation of osteoarthritis.

Epiphyseal pseudotumor secondary to osteoarthritis are rare in patients under 50 years. We report here the case of a 48-year-old woman who complained of pain in the medial side of the left knee for three years. X-rays of the left knee showed a large lytic lesion containing multiple septae, with sclerotic margins at the upper end of the tibia, associated with knee osteoarthritis.