A 10 year old child presents with pallor & history of blood transfusion 2 months back. On investigation, Hb -4.5gm, total count 60000, platelet count- 2lakhs and CD 10(+) ve, CD 19 (+)ve, CD 117 (+) ve, MPO (+) ve & CD 33(-)ve. What is the most likely diagnosis?
**Core Concept:** Leukemia is a group of blood cancers characterized by the uncontrolled proliferation of abnormal white blood cells, platelets, or red blood cells. In this case, we are considering the diagnosis of acute myeloid leukemia (AML).
**Why the Correct Answer is Right:** The laboratory findings provided indicate the presence of immature myeloid cells (CD 10+, CD 19+, CD 117+, MPO+) in the peripheral blood, which is a characteristic feature of AML. Additionally, the absence of CD 33 expression supports the diagnosis, as CD33 is commonly expressed in acute myeloid leukemia.
**Why Each Wrong Option is Incorrect:**
A. Myelodysplastic syndrome (MDS) - MDS is characterized by the dysplastic changes in hematopoietic cells, but lacks the expression of CD 33 typically seen in AML.
B. Acute lymphoblastic leukemia (ALL) - ALL is characterized by the proliferation of lymphoid cells, not myeloid cells. The absence of CD33 expression is also a distinguishing feature of AML.
C. Chronic myeloid leukemia (CML) - CML is characterized by the presence of BCR-ABL fusion gene and is typically associated with CD34 expression, which is not mentioned in the given data.
D. Dengue fever - This option is unrelated to the clinical scenario provided, as it is a viral infection and does not involve abnormal white blood cell proliferation.
**Clinical Pearl:** CD33 expression is a helpful diagnostic marker for AML, and the absence of CD33 expression can be used to exclude certain other related disorders like MDS and CML. Remember that the correct diagnosis would depend on the specific clinical context and further investigations such as bone marrow examination.
**Correct Answer:** B. Acute lymphoblastic leukemia (ALL)
**Explanation:** Although the patient presents with features of leukemia, the absence of CD33 expression and the presence of CD19 expression support the diagnosis of B-cell lineage ALL. However, the correct diagnosis would require further investigations such as bone marrow examination to confirm the presence of blast cells and confirm the presence of Philadelphia chromosome, which is a hallmark of CML.