SYNOVIAL MEMBRANE - Chondromatosis

A plaque of fatty synovial tissue, showing a number of coarsely-nodular papillary areas, up to 2 cm. in diameter; these are white in colour and, although it cannot be seen from the specimen, are cartilaginous in consistency.
About one year before admission, in February 1978, this woman's right knee became very swollen and painful; there was no clear history of trauma. The knee became swollen again shortly before admission and could not be straightened. At operation, the lesion was largely confined to the suprapatellar pouch, and to a small isolated nodule lying in front of the anterior horn of the medial meniscus.