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': "Microscopic examination of a specimen shows 'Psammoma bodies'. They are a characteristic feature of: \nSelect and explain. \nA. Follicular CA of thyroid, B. Papillary CA of thyroid, C. Serous cystadenocarcinoma of ovary, D. Meningioma", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Microscopically, papillary carcinoma consists of single layers of thyroid cells arranged in avascular projections or papillae, which manifest as large pale nuclei, intranuclear inclusion bodies, and anaplastic features. "Psammoma bodies" are laminated calcified spheres and are usually diagnostic of papillary carcinoma. Ref: Lee G.A., Masharani U. (2012). Chapter 42. Disorders of the Thyroid Gland. In A.K. Lalwani (Ed), CURRENT Diagnosis & Treatment in Otolaryngology--Head & Neck Surgery, 3e.', 'role': 'assistant'}]