A 30-year-old presents with massive splenomegaly, leukocytosis (WBC 180,000/μL) with cells at all stages of granulocytic maturation, basophilia, and low LAP score. BCR-ABL1 is positive. Under the 2022 WHO classification, this disease in chronic phase is best categorized as:

• A Chronic myelomonocytic leukemia (CMML)
• B Primary myelofibrosis, prefibrotic stage
• C Essential thrombocythemia with JAK2 mutation
• D BCR-ABL1-positive chronic myeloid leukemia (CML) ✓

Explanation

The 2022 WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues retains BCR-ABL1-positive CML as a distinct entity defined by the t(9;22) translocation creating the Philadelphia chromosome. The clinical features described (massive splenomegaly, full myeloid maturation spectrum, basophilia, low LAP score) are classic CML in chronic phase. CMML shows monocytosis; primary myelofibrosis shows teardrop cells and marrow fibrosis; ET shows isolated thrombocytosis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.