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: Surgery
'Potts puffy' tumour is: 
Select and explain. 
A. A malignant tumour, B. An extradural abscess, C. A tumour or pituitary gland, D. An adrenal gland tumour
B: An extradural abscess
Answer: B: An extradural abscess 
Explanation: None