B-072 Synergy between SF Cube Technology and peripheral blood morphology: clinical impact on early diagnosis and prognosis in a case with Sézary Syndrome

Abstract

Background Sézary syndrome is a rare and aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL), which primarily manifests in the skin before progressing systemically. It is classified as an orphan disease, accounting for up to 3% of all CTCL cases worldwide. Although precise epidemiological data in Latin America are limited, in Peru, the Instituto Nacional de Enfermedades Neoplásicas reported 74 cases of primary cutaneous T-cell lymphoma between 2008 and 2012, highlighting its rarity. The characteristic clinical and hematological triad includes erythroderma, generalized lymphadenopathy, and clonal Sézary cells in peripheral blood, skin, and lymph nodes. Due to its rapid progression, debilitating systemic involvement, and frequent delayed diagnosis, this malignancy is often initially misinterpreted as a benign dermatologic disease. We report a case evaluated using the Mindray BC-6800Plus hematology analyzer, whose findings contributed to the diagnosis of Sézary syndrome. Methods A 38-year-old male presented to outpatient consultation with a 4-month history of erythema of the hands and feet, initially treated as palmoplantar psoriasis without clinical improvement. Two months later, he developed generalized skin involvement associated with multiple lymphadenopathies and was referred with suspected chronic T-cell lymphoproliferative disorder for further evaluation. A peripheral blood sample was collected in a K2-EDTA tube. Complete blood count and leukocyte differential were analyzed using the Mindray BC-6800Plus analyzer. Peripheral blood smears were prepared and morphologically evaluated. Results The CBC revealed: red blood cells 4.11 × 10¹²/L; hemoglobin 126 g/L; hematocrit 37.3%; MCV 90.8 fL; MCH 30.6 pg; MCHC 338 g/L; RDW-CV 13.7%; RDW-SD 45.8 fL; platelets 235 × 10?/L; WBC 22.1 × 10?/L; lymphocytes 8.48%; monocytes 5.48%; eosinophils 0.57%; basophils 0.1%; neutrophils 33.9%; reticulocytes 1.93%; high-fluorescence cells (HFC) 0.1% and 0.01 × 10?/L. Analyzer flags included blasts, abnormal lymphocytes/blasts, monocytosis, lymphocytosis, and leukocytosis. The leukocyte scattergram in the DIFF channel showed a pathological population with increased fluorescence (FL) and heterogeneous side scatter (SSC), displacing the monocyte centroid and extending vertically into the lymphoid region. Peripheral blood smear examination demonstrated large atypical lymphocytes with convoluted, grooved “cerebriform” nuclei, intermediate to mature chromatin, occasional nucleoli, and scant cytoplasm. Conclusions The alerts and scattergram patterns generated by the SF Cube technology of the Mindray BC-6800Plus analyzer were highly suggestive of a pathological lymphoid population and prompted detailed morphological evaluation. Although diagnosis required a multidisciplinary approach with immunophenotyping for confirmation, accurate staging is essential for prognosis and therapeutic decision-making. Identification of Sézary cells allowed classification of the patient into a clinical category requiring immediate treatment, contributing to an early and specific diagnosis with a favorable impact on medium-term quality of life.