This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
[{'content': '"Stary sky" appearance is seen in - \nSelect and explain. \nA. Burkitt\'s lymphoma, B. Mantle cell lymphoma, C. Extra nodal marginal Zone B-cell lymphoma of MALT type, D. Chronic myeloid leukemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The tumor consists of sheets of a monotonous (i.e. similar in size and morphology) population of medium-sized lymphoid cells with high proliferative activity and apoptotic activity. The "starry sky" appearance seen under low power is due to scattered tingible body-laden macrophages (macrophages containing dead apoptotic tumor cells). The old descriptive term of "small non-cleaved cell" is misleading. The tumor cells are mostly medium in size (i.e. tumor nuclei size similar to that of histiocytes or endothelial cells). "Small non-cleaved cells" are compared to "large non-cleaved cells" of normal germinal center lymphocytes. Tumor cells possess small amount of basophilic cytoplasm with three to four small nucleoli. The cellular outline usually appears squared off.', 'role': 'assistant'}]