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
A 40 year male presented with massive splenomegaly. There was mild hepatic enlargement also. Peripheral blood film shows cells with hair like projections; which are positive for CD 25 and CD 103 and negative for CD 23. The likely diagnosis is a : 
Select and explain. 
A. Precursor B - cell neoplasm, B. Peripheral B - cell neoplasm, C. Precursor T-cell neoplasm, D. Peripheral T-cell neoplasm
B: Peripheral B - cell neoplasm
Answer: B: Peripheral B - cell neoplasm 
Explanation: Peripheral B - cell neoplasm Hairy cells on peripheral blood smear and CD 103 positivity are diagnostic of hairy cell leukemia which is a peripheral B cell neoplasm.