Choroidal nodular synovitis is a lesion of the synovial membrane in the joint that can cause fluid accumulation and swelling of the joint. There are two types of synovitis: 1) common villous nodular synovitis 2) pigmented villous nodular synovitis Then, in the second case, the fluid in the joint is bloody and the condition is relatively severe. It should be treated surgically, conservative treatment is not effective.