This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Surgery, Subject name: Surgery
[{'content': 'Cystic compressible, translucent swelling in the posterior triangle of neck:- \nSelect and explain. \nA. Cystic hygroma, B. Branchial cyst, C. Thyroglossal cyst, D. Dermoid cyst', 'role': 'user'}, {'content': "Answer: A \nExplanation: Cystic compressible, translucent swelling in the posterior triangle of neck is cystic hygroma. CYSTIC HYGROMA Multiloculated cystic spacesQlined by endothelial cells Due to sequestration of a poion of jugular lymph sac from the lymphatic systemQ. Cysts are filled with clear lymph and are lined by endotheliumQ. Turner's syndromeis associated with cystic hygromaQ. Most cystic hygromas involve the lymphatic jugular sacs MC site: Posterior neck regionQ(Posterior triangleQ) Other common sites: Axilla, mediastinum, inguinal & retroperitoneal regionsQ CLINICAL FEATURES Usually present as soft cystic masses that disto the surrounding anatomy, can result in acute airway obstruction. Usually manifests in the neonates or in early infancyQ(50% present at bih). Characteristic feature: Brilliantly translucentQ", 'role': 'assistant'}]