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: Gynaecology & Obstetrics
[{'content': 'A 40 year old woman who presented with severe abdominal pain, fever and nausea was taken up for explorative laparotomy. It revealed a purple red tumour on the uterus with fishy odour. On careful examination some of the large veins on the tumour were thrombosed. What is the possible diagnosis? \nSelect and explain. \nA. A sarcomatous change in a pre existing myoma, B. Fatty degeneration of a myoma, C. Red degeneration of a myoma, D. Hyaline degeneration of a myoma', 'role': 'user'}, {'content': "Answer: C \nExplanation: Red degeneration is a complication of uterine myoma, though it mostly occurs in pregnancy it is not a rare cause of painful myomas in woman over the age of 40. Sarcomatous change in myoma is extremely rare and is yellow - gray in colour with haemorrhages to the naked eye. Ref: Shaw's Textbook of Gynaecology, 13th Edition, Pages 340-41.", 'role': 'assistant'}]