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: ENT
Fisch classification is used for classifying which of the following malignancy? 
Select and explain. 
A. Paraveebral tumours, B. Glomus tumor, C. Synol sarcomas, D. Retroperitoneal tumours
B: Glomus tumor
Answer: B: Glomus tumor 
Explanation: The two grading systems which has been developed to classify glomus tumors are Fisch classification and Glasscock - Jackson classification. Fisch classification of glomus tumors: Class A: Tumors limited to the middle ear cleft. Class B: Tumors limited to the tympanomastoid area without destruction of bone in the infralabrynthine compament. Class C: Tumors extending into and destroying the bone of the infralabrynthine and the apical compaments of the temporal bone. Class D: Tumors with intracranial intradural extension.