NK-Lymphoblastic Leukemia/Lymphoma: An Enigma

Excerpt

A 59-year-old man was investigated for fever, headache, and blurring of vision. On physical examination, he had hepatosplenomegaly. PET/CT revealed multiple intra-thoracic and intra-abdominal lymphadenopathy. A complete blood count showed leucocytosis (90.4 × 10⁹ /L) with anemia (9.8 g/dL) and thrombocytopenia (77 × 10⁹/L). The peripheral blood smear showed the presence of 75% pleomorphic, medium- to large-sized atypical cells with mostly irregularly shaped nuclei, high nuclear/cytoplasmic ratio, and immature, blastic chromatin with multiple nucleoli (Fig. 1A). Bone marrow examination revealed infiltration by 80% of similar morphology cells. On immunophenotyping, these cells were: CD45bright⁺/CD2⁺/CD7⁺/CD43^dim+/CD94⁺/cytoplasmicCD3⁻/CD5⁻/CD28⁻/CD4⁻/CD8⁻/TdT⁻/CD19⁻/CD10⁻/CD117⁻/CD33⁻/CD13⁻/CD56⁻/Perforin⁻/TCRαβ⁻/TCRγδ⁻/HLA-DR⁺/cytoplasmicCD79a⁻/CD30⁻ /CD57⁻ /CD16⁻/CD11c⁻/CD25⁻/cytoplasmic MPO⁻/CD64⁻ /CD14⁻. This suggested a diagnosis of Natural Killer (NK) cell lymphoblastic leukemia/lymphoma. The patient was started on cyclophosphamide, dexamethasone, and etoposide. However, he developed tumor lysis syndrome and succumbed to the disease.

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