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: Pathology
L.E. Cell phenomenon in peripheral blood is seen in: 
Select and explain. 
A. Rheumatic heart disease, B. Infective endocarditis, C. Ischemic heart disease, D. Systemic Lupus Erythernatosus
D: Systemic Lupus Erythernatosus
Answer: D: Systemic Lupus Erythernatosus 
Explanation: The addition of blood serum from a person under suspicion to the buffy coat of normal blood is the basis for L.E .cell phenomenon. If the patient is L.E. -we, then typical "LE" Cell develop. The cell consists of rosette of neutrophils surrounding a pale nuclear mass, derived from a Lymphocyte.