Case History

The patient is a 65-year-old female with a known history of osteoarthritis, managed on regular medication. She was asymptomatic and was incidentally found to have lymphocytosis during routine blood testing over past six months. On physical examination, there was no lymphadenopathy or hepatosplenomegaly.

Complete blood count (CBC) revealed: WBC 7.64 × 10³/µL, hemoglobin 11.8 g/dL, and platelets 328 × 10³/µL. Differential count showed neutrophils 26%, lymphocytes 63%, monocytes 9%, and eosinophils 2%.

Peripheral blood smear demonstrated absolute lymphocytosis (4,813 cells/µL) with large granular lymphocytes. Further evaluation with flow cytometry confirmed the diagnosis of T-cell large granular lymphocytic (TLGL) leukemia.