上颌窦粘液囊肿,临床上较为常见。继发感染,形成脓囊肿,破坏窦壁,经鼻底部,侵及对侧上颌窦,尚属罕见。现经治一例,报告如下。病例刘某,男38岁,右额部隆起发胀半年,近半月加重,遂来院门诊.经右鼻底外侧肿块穿刺,抽出黄色液体,涂片镜检见胆固醇结晶及多量嗜中性粒细胞。华氏位摄片,未见明显肿块影。拟诊“鼻前庭 Maxillary sinus mucosal cysts, clinically more common. Secondary infection, the formation of pus cysts, destruction of the sinus wall, nasal floor, invasion and contralateral maxillary sinus, is still rare. Now a rule, the report is as follows. Case Liu, male, 38 years old, right forehead swollen swollen half a year, nearly half of the increase, then to the hospital clinic by the right nasal endoscopic mass puncture, out of the yellow liquid, smear microscopic examination of cholesterol crystals and a large number of neutrophils . Fahrenheit radiography, no significant mass shadow. To be diagnosed "nasal vestibule