This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acute Myelogenous Leukemia, Subject name: Pathology
AML with gum infiltration, hepato- splenomegaly is most likely to be: 
Select and explain. 
A. ALL, B. M3, C. M2, D. M4
D: M4
Answer: D: M4 
Explanation: In tumors with monocytic differentiation M4 and M5 (more commonly) infiltration of the skin (leukemia cutis) and the gingiva leading to gum hyperophy can be observed M4 and M5 both show gum hyperophy and leukemia cutis. M4 is positive for MPO +. M5 is positive for Non Specific esterase .