From a discussion of four cases of unusual mucinous tumors of the knee joint, including two which are probably cysts of the meniscus (one with an unusual amount of bone change), one which is probably an unusually extensive development of a parameniscal cyst, and one which is a true myxomatous tumor of the meniscus, it appears that cysts of the menisci apparently are not true neoplasms, but represent the end results of degeneration.
Such cysts may sometimes be distinguished from other cysts in the region of the knee joint by the absence of endothelial lining.