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
A 15-year-old boy presented with one day history of bleedig gums, subconjunctival bleed and purpuric rash. Investigations revealed the following results:Hb-6.4 gm/dL; TLC-26,500/mm3 Platelet 35,000 mm3; prothrombin time-20 sec with a control of 13 sec; paial thromboplastin time-50sec; and Fibrinogen 10mg/dL. Peripheral smear was suggestive of acute myeloblastic leukemia. Which of the following is the most likely - 
Select and explain. 
A. Myeloblastic leukemia without maturation, B. Myeloblastic leukemia with maturation, C. Promyelocytic leukemia, D. Myelomonocytic leukemia
C: Promyelocytic leukemia
Answer: C: Promyelocytic leukemia 
Explanation: Ans. is 'c' i.e. promyelocytic leukemia o The child presents with acute onset of bleeding, along with the following laboratory anamolies. (i) Thrombocytopenia (iii) Increased paial thromboplastin time. (ii) Increased prothrombin time (iv) Decreased Fibrinogen o These hematological abnormalities indicate Disseminated intravascular coagulation o The peripheral blood smear of the patient is suggestive of acute myeloblastic leukemia (mentioned in the question) The AML most likely to occur in this setting is promyelocytic leukemia as it is the most common myeloid leukemia assciated with DIC o Promyelocytic (AML-M3) leukemic promyelocytes liberate tissue thromboplastin leading to disseminated intravascular coagulation.