This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Osteology, Subject name: Pathology
X Ray shows lytic lesion in calceneus in young adult. Biopsy shows following diagnosis 
Select and explain. 
A. Pigmented viilonodular synovitis, B. Ochronosis, C. Osteomylitis, D. Eumycosis
A: Pigmented viilonodular synovitis
Answer: A: Pigmented viilonodular synovitis 
Explanation: Ans. (a) Pigmented viilonodular synovitisImage shows hyperplasia of synomin along with hemosiderin laden macrophages and giant cells s/o Pigmented viilonodular synovitis.