This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Single Gene Disorders, Subject name: Pathology
[{'content': 'Reinke crystalloids can be seen in which of the following sex cord-stromal tumours? \nSelect and explain. \nA. Leydig cell tumour, B. Granulosa cell tumour, C. Gonadoblastoma, D. Thecoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hilus cell tumours (pure Leydig cell tumours) are rare, unilateral tumors comprised of large lipid-laden Leydig cells with distinct borders and characteristic cytoplasmic structures called Reinke crystalloids.', 'role': 'assistant'}]