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': 'Marker of small cell cancer of lung is \nSelect and explain. \nA. Chromogranin, B. Cytokeratin, C. Dermin, D. Vimentin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Small cell cancer of lung\xa0\n\nTumor cells are small round or spindle shaped with prominent nuclear molding.\nThey will have scant cytoplasm, ill-defined cell borders, finely granular nuclear chromatin (salt and pepper pattern) and abesnt or inconspicuous nucleoli.\nAzzopardi effect is characteristic of small cell cancer of lung .\nUltra structurally the cancer cells exhibit dense core neurosecretory granules consisting of neuroendocrine markers like chromogranin, Synaptophysin, CD57 and bomberin.\nImmunohistochemistry demonstrates high levels of the antiapoptotic protein BC22 in 90% of tumors.\nMost common lung cancer with ectopic hormone production.', 'role': 'assistant'}]