Treatment of thyroglossal duct cysts by Ok‐432

INTRODUCTION Although surgery is the treatment of choice for thyroglossal duct cysts, it can give rise to complications, including nerve injury, cyst recurrence, wound infection, and cosmetic problems. Use of a nonsurgical procedure could prevent these complications. Although simple aspiration of otolaryngological cystic diseases is a noninvasive treatment, cyst recurrence is commonly observed despite repeated aspiration. Ogita et al. reported in 1987 that OK-432 therapy was effective for lymphangioma. OK-432 was originally developed as an immunotherapeutic agent for cancer, but it is widely accepted that it is very effective in reducing ascites and pleural effusion in patients with carcinomatous peritonitis and pleuritis. When it is injected into the peritoneal or pleural cavity, reduction of ascites and pleural effusion occurs and adhesion of the cavity develops. OK-432 therapy is also effective for lymphangioma, branchial cleft cysts, salivary mucocele, auricular hematoma, thyroid cysts, cervical lymphocele, and plunging ranula, but studies of the effectiveness of OK-432 in treating thyroglossal duct cysts have been rare. The purpose of this study was to investigate the effectiveness of OK-432 therapy in patients with thyroglossal duct cysts.