Abstract
We present a case of lymphocytosis assumed and managed initially as a chronic lymphocytic leukemia. Shortly after initial visit, the patient's condition deteriorated rapidly with hepatosplenomegaly, pleural effusion, ascites, and skin lesions. Flow cytometry (FC) showed the presence of clonal T-cell population, reported as T-cell lymphoma. Due to rapid clinical deterioration, urgent therapy with cyclophosphamide, doxorubicin, vincristine, etoposide, prednisone was initiated, but with minimal response. This prompted further diagnostic testing and demonstrated tumor cells positivity for CD3, CD30, and TCL1 markers. The diagnosis was changed to T-cell prolymphocytic leukemia. The patient responded well to alemtuzumab (anti-CD52 monoclonal antibody) and reached complete remission. FC is an essential modality for assessing and screening circulating lymphocytes when a lymphoproliferative disorder (LPD) is suspected. There are several LPDs that present with different degrees of clonal lymphocytosis. Reactive lymphocytosis should be appropriately investigated. Indolent LPDs can be surveyed by the internist or family physician, while more aggressive LPDs typically require management by hematologists.