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: Medicine
Pancytopenia with hypercellular marrow could be due to all, EXCEPT: 
Select and explain. 
A. Myelodysplasia, B. Paroxysmal nocturnal hemoglobinuria, C. Sarcoidosis, D. Dyskeratosis congenita
D: Dyskeratosis congenita
Answer: D: Dyskeratosis congenita 
Explanation: Dyskeratosis congenita is associated with pancytopenia and hypocellular bone marrow. Pancytopenia with hypercellular marrow is seen in: Myelodysplasia Myelofibrosis Hairy cell leukemia Tuberculosis Sarcoidosis Brucellosis PNH Hypocellular Bone marrow +/- Cytopenia: Q fever Legionnaires disease Anorexia nervosa, starvation Mycobacterium