A 68-year-old man with a 20 pack-year smoking history presents with hemoptysis, dyspnea, and constitutional symptoms. Chest imaging reveals a left upper lobe mass with mediastinal lymphadenopathy. Bronchoscopy with biopsy confirms small cell lung cancer (SCLC). Laboratory evaluation shows WBC 3,500/μL (reference 4,500-11,000), hemoglobin 9.2 g/dL, and platelets 95,000/μL. Peripheral blood smear shows 2% circulating blasts. Flow cytometry is performed to evaluate for concurrent hematologic malignancy. Which of the following findings would most strongly suggest a clonal hematologic process rather than reactive cytopenia from paraneoplastic or toxic effects?
- A)CD34+ cells comprise 3% of total WBC with polyclonal immunoglobulin light chain expression
- B)Absolute neutropenia with preserved monocyte and lymphocyte percentages
- C)CD34+ cells comprise 8% of total WBC with clonal T-cell receptor gene rearrangementGABARITO
- D)CD13+ and CD33+ myeloid markers with abnormal maturation and increased myeloid blasts
- E)Mild reduction in CD8+ T cells with oligoclonal T-cell receptor pattern
Explicação
Increased CD34+ cells (>5% of WBC) combined with clonal T-cell receptor rearrangement confirms a clonal lymphoid proliferation consistent with concurrent acute lymphoblastic leukemia or lymphoma. This combination of findings indicates a true hematologic malign... Ver explicação completa e trilha adaptativa →