This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pediatrics, environment and nutrition, Subject name: Pathology
[{'content': 'Rosettes are characteristically seen in - \nSelect and explain. \nA. Retinoblastoma, B. Melanoma, C. Dysgerminoma, D. Lymphoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Robbins basic pathology 9th edition page no 261, Differentiated structures are found within many retinoblastomas, the most common of these being Flexner-Wintersreiner rosettes. These structures consist of clusters of cuboidal or sho columnar cells arranged around a central lumen. The nuclei are displaced away from the nucleus. In well-differentiated tumors, there are Flexner-Wintersteiner rosettes and fleurettes reflecting photoreceptor differentiation', 'role': 'assistant'}]