Fig. 3From: Primary lipoma arborescens of the knee may involve the development of early osteoarthritis if prompt synovectomy is not performedHistological view of a hyperplastic process characterized by a diffuse replacement of the subsynovial tissue with mature fat cells, causing villous expansion of the synovium. Inflammatory cells are observed around capillaries (haematoxylin and eosin ×30)Back to article page