An 82-year-old male with well-controlled HIV and macrocytic anemia undergoes a bone marrow biopsy. The morphologic findings are subtle, including few slightly atypical eosinophils on peripheral blood, mild granulocytic hyperplasia, a single paratrabecular cluster of eosinophils, and few spindled mast cells. There is no overall marrow or blood eosinophilia. Karyotype detects a t(4;22)(q12;q11.2) clonal abnormality involving PDGFRA (4q12) by break-apart FISH. Mate pair sequencing demonstrates a fusion between the PDGFRA and SPECC1L genes.
|Daniel (Dan) P. Larson, M.D.
Resident, Anatomic and Clinical Pathology
|Pedro Horna, M.D.
Senior Associate Consultant, Hematopathology
Associate Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine