Mixed phenotype acute leukemia in thalassodrepanocytosis

Mixed phenotype acute leukemia in thalassodrepanocytosis
Author: Andrea Duminuco; Francesco Di Raimondo; Giuseppe A. M. Palumbo; Ausilia Gorgone; Rosamaria Rosso; Nunziatina Parrinello; Calogero Vetro
Category: Myeloid Neoplasms and acute leukemia (WHO 2016) > Acute leukemias of ambiguous lineage
Published Date: 11/05/2021

A 61-years-old man affected by thalassodrepanocytosis (b+/S), with several previous sickle cell crises with pulmonary and renal sequelae besides autosplenectomy, presented cause intense asthenia and lymphadenopathy. Blood count revealed anemia (Hb 7 g/dL), light thrombocytopenia (platelets 140 000 x 103 /uL) and hyperleukocytosis (white blood cells 111 000 /uL). Hemoglobin S value at HPLC was lower than 20%. As shown in figure 1, morphological evaluation of peripheral blood smear (A-E) showed, besides target cells (1), erythroblasts (2) and some myeloid precursors (3), 60% blasts. No sickle cells were detectable. Some blasts had L1- (4) or L2-like (5) morphology and, in part, hand-mirror shape (6), while some had monocytoid feature (7), partly with granules and partly with vacuoles in cytoplasm. Neutrophils showed packed Auer rods (8). Broken, “Gumprecht’s shadows-like” cells, were detectable (9). Bone Marrow evaluation showed dysplastic signs of myeloid precursors, e.g. pseudo-Pelger-Huet anomalies (F, 10), and 90% blasts with phenotype reported in figure 2 plots: MPO+, CD45+, CD117+ (myeloid lineage antigens), cyCD3+, CD1a+, CD7+, CD99+ (T-lineage antigens) and CD19+, HLA-DR+, cyCD22+, CD200+, TdT+, CD79a+ (B-lineage antigens), as shown in Panel G. According to 2016 WHO Classification a mixed phenotype acute leukemia (MPAL) was diagnosed, with extremely rare immunophenotypic features (B/T/myeloid antigens simultaneously present). The disease onset was too aggressive and the patient died one week later.