<s>[INST] context: Tracheal stenosis Management of tracheal stenosis The optimal treatment of tracheal stenosis remains undefined Traditionally tracheal stenosis has been managed by thoracic and otorhinolaryngology surgeons. Endoscopic procedures are usually performed as bridge to definitive surgical intervention. With the development of interventrical pulmonology field in the last 20 years definitive management of tracheal stenosis using minimally invasive endoscopic methods becomes a possibility. Endoscopic surgery has been shown to be useful especially in patients who are deemed high risk and too unwell for reconstructive surgery. One of the main drawbacks of endoscopic tit and surgery is the risk of recurrence of tracheal stenosis due to granulation and fibrotic tissue. Scar formation and restenosis is the main cause. Studies have shown that most of the recurrence of tracheal stenosis occurs within one to three months after the procedure and use of mitomycin C has been repoed in case studies to reduce the rate of recurrence. - Both in vitro and invivo mitomycin C has been proved to be a potent inhibitor of human fibroblasts at concentrations of .04 mg/L Topical mitomycin C is a useful adjunct in the management of sho concentric membranous stenosis which does not involve the cailage. [/INST] question: Topical mitomycin C is used in the treatment of aEUR' | options: A: >Basal skull ca B: >Tracheal stenosis C: >Skull base osteomyelitis D: >Angiofibroma | answer: C </s>