Pigmented villonodular synovitis (PVNS) is a joint problem that usually affects the hip or knee. It can also occur in the shoulder, ankle, elbow, hand or foot. In PVNS the lining of the joint becomes swollen and grows. This growth harms the bone around the joint. The lining also makes extra fluid that can cause swelling and make movement very painful. PVNS is idiopathic, it doesn't seem to run in families or be caused by certain jobs or activities. Surgery can help but, even with treatment, PVNS comes back about half the time. If the pain remains then radiation therapy may help. In the worst cases the joint must be replaced.

--------------------------------------------------
Note added at 2 hrs (2011-03-12 16:30:42 GMT)
--------------------------------------------------

Λαχνοοζώδης υμενίτιδα

Η λαχνοοζώδης υμενίτιδα αποτελεί ομάδα καλοήθων όγκων, οι οποίοι προσβάλλουν το επιθήλιο του αρθρικού υμένα, τα έλυτρα των τενόντων και τους θυλάκους. Στην ομάδα αυτή περιλαμβάνονται η μελαγχρωστική λαχνοοζώδης υμενίτιδα (PVNS), η εντοπισμένη ή οζώδης υμενίτιδα, η εντοπισμένη ή οζώδης τενοντοελυτρίτιδα και η εντοπισμένη οζώδης θυλακίτιδα.

http://www.e-rheumatology.gr/scientific-articles/laxnoozodis...