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Difficulty: Very hardHematology and Oncology

Match each diagnostic hematologic profile with its corresponding primary molecular pathogenesis and targeted therapeutic approach.

  • Bone marrow aspirate shows hypercellularity with >20% blasts containing abundant cytoplasm, multiple Auer rods, and strong myeloperoxidase positivity; cytogenetics reveal a t(15;17) translocation.Disruption of normal retinoic acid receptor signaling leading to maturation arrest; definitive management includes a vitamin A derivative and arsenic trioxide.
  • Peripheral blood flow cytometry demonstrates a clonal B-cell population expressing CD19, CD20, CD11c, CD25, CD103, and CD123, with marked monocytopenia.An activating mutation in the BRAF gene (V600E) is almost universally present; first-line therapy typically involves purine analogs such as cladribine.
  • Lymph node biopsy reveals an effaced architecture with a monotonous proliferation of small-to-medium lymphocytes; FISH is positive for t(11;14)(q13;q32).Overexpression of Cyclin D1 leads to dysregulation of the cell cycle at the G1-to-S phase transition; treatment may involve Bruton tyrosine kinase (BTK) inhibitors.
  • Bone marrow evaluation of a patient with massive splenomegaly shows marked fibrosis and megakaryocytic atypia; molecular testing reveals a gain-of-function mutation in the JAK2 gene (V617F).Constitutive activation of a non-receptor tyrosine kinase leads to hypersensitivity to hematopoietic cytokines; ruxolitinib can be used to ameliorate constitutional symptoms and splenomegaly.
  • Bone marrow biopsy reveals >10% clonal plasma cells, and flow cytometry shows CD38+ and CD138+ cells; peripheral blood shows rouleaux formation.Overproduction of monoclonal immunoglobulins or light chains leads to renal tubular toxicity and osteoclast activation; proteasome inhibitors are a cornerstone of therapy.

Answer

Acute promyelocytic leukemia matches with retinoic acid receptor disruption. Hairy cell leukemia matches with the BRAF V600E mutation. Mantle cell lymphoma matches with Cyclin D1 overexpression. Primary myelofibrosis matches with constitutive non-receptor tyrosine kinase activation. Multiple myeloma matches with monoclonal immunoglobulin overproduction.
Each diagnostic profile presents hallmark cytogenetic, immunophenotypic, or morphological features of a specific hematologic malignancy. Accurate matching requires linking these diagnostic features to their direct pathophysiological consequences and standard-of-care treatments.

Step-by-Step Solution

1
Analyze the diagnostic profile for the first item.
Identifies acute promyelocytic leukemia (APL) based on greater than 20% blasts, multiple Auer rods, and the t(15;17) translocation.
Recognizing the unique cytogenetic and morphological signature of APL is required to determine the specific molecular mechanism.
2
Match APL with its pathogenesis and targeted treatment.
Links APL to the disruption of retinoic acid receptor signaling and treatment with a vitamin A derivative (ATRA) and arsenic trioxide.
The PML-RARA fusion protein creates a maturation block that specific targeted therapies can overcome.
3
Evaluate the immunophenotype of the second item.
Identifies hairy cell leukemia from the specific CD markers (CD11c, CD25, CD103) and marked monocytopenia.
This distinct flow cytometry profile differentiates it from other indolent B-cell neoplasms.
4
Connect hairy cell leukemia to its genetic driver and therapy.
Links to the BRAF V600E mutation and purine analog therapy, such as cladribine.
The BRAF mutation is nearly universal in this disease and dictates targeted therapeutic approaches.
5
Assess the cytogenetics of the third item.
Identifies mantle cell lymphoma based on t(11;14) and the proliferation of small-to-medium lymphocytes.
The translocation uniquely identifies this lymphoma subtype among other small B-cell lymphomas.
6
Associate mantle cell lymphoma with its molecular consequence.
Links t(11;14) to Cyclin D1 overexpression and potential treatment with Bruton tyrosine kinase (BTK) inhibitors.
Cyclin D1 drives the G1-to-S phase transition, characteristic of this aggressive lymphoma.
7
Analyze the bone marrow findings of the fourth item.
Identifies primary myelofibrosis due to massive splenomegaly, marked fibrosis, megakaryocytic atypia, and the JAK2 mutation.
Clinical and molecular features precisely define this myeloproliferative neoplasm.
8
Connect primary myelofibrosis to its pathophysiology and symptomatic treatment.
Links to constitutive activation of a non-receptor tyrosine kinase (JAK2) and ruxolitinib therapy.
Targeted JAK inhibition effectively controls massive splenomegaly and constitutional symptoms.
9
Evaluate the diagnostic findings in the fifth item.
Identifies multiple myeloma based on greater than 10% clonal plasma cells, CD38/CD138 positivity, and rouleaux formation.
These are the classic diagnostic criteria for this plasma cell dyscrasia.
10
Match multiple myeloma to its disease mechanisms and core therapy.
Links to monoclonal protein overproduction causing end-organ damage and treatment with proteasome inhibitors.
Proteasome inhibitors are uniquely effective due to the heavy protein synthesis burden in malignant plasma cells.

Key Concept

Molecular pathogenesis, diagnostic criteria, and targeted therapies for specific hematologic malignancies.
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Topics

Hematology and Oncology

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