What causes painful cyst under the knee?
Patient: about 2 weeks ago i got a non painfull squishy lump just below the neecap on my leg the next day brusing started to appear on my knee and shin it has slowley moved around my shin and started in the left side of my foot it is now on the right side of my foot an on the top of my foot near the toes and on my toes Doctor: Hi,Dear,Thanks for the query to HCM. I studied your problem in depth and I understood your concerns. Causes  for the painful cyst undrer the knee-In my opinion your non-painful lump below knee cap-appears to have re-activated infection in it and has caused cellulitic spread till top of the foot of leg.This has developed due to the possible blood infection of the existing cyst or due to re-activation of the chronic died out cystic swelling below the knee.This advise is based on the facts from the history you give and needs further clinical check.So don't build up wrong concepts and create more psychic complications in you which would increase risks and costs to you.Hope this would relieve your problem.Welcome for any more query in this regard to HCM.Write good resume and Click thanks if you feel satisfied with my advise.Have a Good Day.Dr.Savaskar M.N.