HI. There are few reasons for recurring granulation tissues even after silver nitrate treatment:: Biopsy reports - What is the biopsy report? This can be due to tuberculosis This can be due to mycoses. This can be due to foreign body reaction may be to the non-dissolving stitches or so. Cancer has already been ruled out. Empirical treatment with Anti-tubercular treatment or long term sulpha or penicillin can help.