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An 83-year-old female with a history of chronic lymphocytic leukemia (CLL) presented with a new painless right neck lump and axillary swelling.  A peripheral smear review demonstrated a WBC count of 44 x 10³/µL and an absolute lymphocyte count of 34 x 10³/µL with a predominance of CLL-like cells.  In addition, there were 5% large cells with condensed chromatin, not seen on previous smear reviews (top and bottom right images, ×1000 oil immersion).  The findings prompted a subsequent axillary biopsy with flow cytometry remarkable for a dim kappa restricted B-cell population with increased side scatter expressing CD19, dim CD20, CD5, CD23, and CD200.  Histology showed sheets of large cells with prominent nucleoli, diagnostic of Richter’s transformation (bottom left image). Immunohistochemistry revealed that the cells were positive for dim CD20, dim MUM1 (>30%), dim BCL6 (>30%), and CD5 but negative for Cyclin D1, and EBER in situ hybridization. The sample demonstrated a 50% Ki67 proliferation index and wild-type p53 expression.  Large cell transformation from CLL occurs in 2-8% of patients and is rarely found on peripheral smear.  This case highlights the importance of peripheral blood smear evaluation in disease surveillance and histomorphologic characterization of this entity.