This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': 'Thorn wait cyst - \nSelect and explain. \nA. Laryngeal cyst, B. Nasopharyngeal cyst, C. Ear cyst, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Nasopharyngeal cyst Thornwaldt cvst (nasopharyngeal cyst)o A thornwaldt cyst is a benign midline nasopharyngeal mucosal cyst.o It is a developmental anomaly Which is usually asymptomatic and is found incidentally on imaging of nasopharynx. This is a notochord remnant.o Sometimes cyst may become infected and can cause halitosis or foul tasting periodic discharge into the mouth.o Asymptomatic lesions require no treatment. If treatment is required then de-roofing the cyst (marsupialization) is usually sufficient, and can be performed via a transpalatal approach.Also knowo Thornwaldt's disease is infection of pharyngeal bursa, i.e. pharyngeal bursitis", 'role': 'assistant'}]