This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Dermoid arises from - \nSelect and explain. \nA. Pluripotent cell, B. Totipotent cell, C. Ectoderm, D. Mesoderm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dermoids or benign cystic teratomas are derived from the ectodennal differentiation of totipotent cells.\nSome characteristic features of Dermoids or Benign Cystic teratomas \n\nThey are a common neoplasm of the ovary with bilaterally seen in 10-15% of cases.\nCharacteristically, they are unilocular cysts containing hair and cheesy sebaceous material.\nthe internal lining of cyst is mostly smooth but frequently has a knob-like nodular protrusion in one area (the umbo) in which cartilage, bone and well formed teethi may be present.\nOn histological examination, the cyst wall is composed of stratified squamous epithelium with underlying sebaceous glands, hair shafts and other skin adnexal structures.\nRarely ovarian teratomas are composed almost entirely of thyroid tissue k/a struma ovarii\nAbout 1% of dermoids undergo malignant transformation of any one of the component elements (eg. thyroid ca, melanoma but most commonly, squamous cell ca)', 'role': 'assistant'}]