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: Pathology
[{'content': 'Psammoma bodies are seen in - \nSelect and explain. \nA. Thyroid carcinoma, B. Carcinoma breast, C. Carcinoma stomach, D. Carcinoma testis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Papillary thyroid carcinoma\n\nIt is the most common type of thyroid cancer.\nCarcinoma cells have nuclei which contain finely dispersed chromatin, which imparts optically clear or empty appearance, giving rise to the ground glass or Orphan Annie eye nuclei.\nInvagination of cytoplasm may give rise to the appearance of intranuclear inclusions (pseudoinclusions) or intranuclear grooves the diagnosis of papillary carcinoma is based on these nuclear features.\nPsammoma bodies are present\nLymphatic metastasis may be seen but the involvement of blood vessels is rare.', 'role': 'assistant'}]