Blastoid NK Cell Leukemia/Lymphoma with Cutaneous Involvement

Abstract

Malignant neoplasms from natural killer (NK) cells are characterized by their positivity for CD56 and absence of monoclonal TCR gene rearrangement. Recently, they have been classified into four main types (nasal and nasal-type NK cell lymphoma, aggressive NK cell leukemia/lymphoma, and blastoid NK cell leukemia/lymphoma), based on clinical features, racial predisposition, presence of azurophilic granules, immunophenotype and association with Epstein-Barr virus (EBV) infection. A 72-year-old Caucasian man presented with a malignant neoplasm comprised of blastoid cells without azurophilic granules in the Giemsa stain, with positivity for CD2, CD4, HLA-DR, CD45 and CD56, and negativity for CD3 (surface and cytoplasmic) and CD5. In situ hybridization for EBV and PCR analysis of rearrangement of the T cell receptor gene were negative. Based on these results, a diagnosis of blastoid NK cell lymphoma was made. In this case the first clinical manifestations were the cutaneous lesions, and, although the disease was already advanced at the diagnosis, the patient responded completely to the treatment and remains asymptomatic 14 months after diagnosis.

T-cell prolymphocytic leukemia: An aggressive T cell malignancy with frequent cutaneous tropism

“…The blastic natural killer cell lymphoma has emerged as a distinctive form of hematologic malignancy that has been renamed as hematodermic neoplasm, recognizing that the cell of origin is a plasmacytoid dendritic cell. [38][39][40][41][42][43] Like T-PLL, these tumors are aggressive neoplasms with a propensity to involve the skin and bone marrow early in its course and affect elderly individuals. The tumor cells express CD4, CD56, and CD123 and do not express CD2 or CD3.…”

What is CD4+CD56+ malignancy and how should it be treated?

“…Only two authors reported sustained CR (7%) after this therapy; one young patient with skin-restricted disease had radiotherapy; another, a 72-year-old man with widespread disease, was treated with cyclophosphamide, methotrexate, vincristine and intrathecal prophylaxis. 24,31 However, the observation time for the two patients was only 14 and 18 months, respectively. The median overall survival for all evaluable patients is only 9 months and Kaplan-Meier curves do not suggest curative potential for this therapeutic approach (Figure 2).…”

CD4+/CD56+ Hematodermic Tumor

“…This finding may be bolstered by the presence of megaloblastoid erythroid maturation and tumorassociated monocytosis. Fulminant leukemia is a common feature of HDT progression or relapse and is nearly always Chan et al, 8 DiGiuseppe et al, 9 Bayerl et al, 10 and Falcao et al 11 (Lympho)blastoid NK-leukemia/lymphoma Estalilla et al, 12 Ginarte et al, 13 present in the terminal stage. As described later, relapse as myelomonocytic leukemia also occurs.…”