This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
A black necrotic mass was seen in the nose of an elderly diabetic patient. The most probable diagnosis is? 
Select and explain. 
A. Lupus vulgaris, B. Aspergillosis, C. Mucormycosis, D. Pseudomonas infection
C: Mucormycosis
Answer: C: Mucormycosis 
Explanation: The most probable diagnosis is mucormycosis which is a fungal infection of the nose and paranasal sinuses. It is seen in those on immunosuppressive therapy or those with uncontrolled diabetics. It is associated with rapid destruction due to the affinity of the fungus to aeries causing endothelial damage and thrombosis. A typical finding is the presence of a black necrotic mass filling the nasal cavity and eroding the septum and hard palate. Ref: Textbook of diseases of ENT; PL Dhingra; 7th edition, pg no. 178