CD56⁺ TdT⁺ blastic natural killer cell tumor of the skin

Abstract

BACKGROUNDAn unusual cutaneous tumor that has blastic morphology and coexpresses CD56 and terminal deoxynucleotidyl transferase (TdT) has been recently recognized and termed blastic natural killer cell lymphoma.METHODSThe authors identified seven cases of such CD56+TdT+ blastic tumors presenting in skin at their institution. The authors correlated clinical course with histomorphology and immunophenotype.RESULTSAll 7 patients (6 men, 1 woman, 52‐85 years) presented with rapidly growing, frequently multiple cutaneous nodules. All patients had low level bone marrow involvement at diagnosis and frequently had lymph node involvement. Tumor cells were of intermediate size with irregular nuclear contours, fine chromatin, and indistinct small nucleoli. The expression of TdT varied between 5% and over 90% of the neoplastic cell population. Tumor cells were negative for surface CD3, CD5, and CD20 in all cases, but some patients showed expression of CD2 (three out of five), cytoplasmic CD3 (two out of seven), CD4 (six out of seven), and CD16 (three out of seven). Molecular studies showed absence of T‐cell receptor gene rearrangements in all cases. All seven patients had rapid progression of disease, and six patients have died of their disease or complications. Three patients developed progressively increasing numbers of bone marrow blasts that had a myeloid immunophenotype and were negative for TdT and CD56. Two patients met criteria for acute myeloid leukemia at 11 and 22 months after presentation, respectively.CONCLUSIONSCD56+ TdT+ blastic tumor presenting in skin is a systemic malignancy likely of primitive/undifferentiated hematopoietic origin. Patients might subsequently develop tumors of myeloid or myelomonocytic phenotype, indistinguishable from acute myelogenous leukemia. Cancer 2002;94:2401–8. © 2002 American Cancer Society.DOI 10.1002/cncr.10489

CD4‐negative variant of CD4+/CD56+ hematodermic neoplasm: description of three cases

“…In the literature, we found only four cases that could be considered CD4-negative variants of genuine HN. [9][10][11] Similar to our cases, these cases showed some phenotypic variability, underlying the necessity for a large panel of antibodies in the diagnosis of HN. In fact, the two cases of HN described by Bekkenk et al 10 were positive for TdT and also expressed some T-cell markers (one case was CD81 and CD52/1, and the second was CD21).…”

“…On the other hand, cases of HN with ambiguous phenotype could represent examples of blastic tumors with mixed precursor plasmacytoid dendritic and myelomonocytic features, possibly representing a spectrum of precursor hematologic neoplasms. This hypothesis is supported by the evidence that patients with HN can develop AML during the course of the disease 9,15 or can present at diagnosis with a concurrent myeloproliferative disorder. 4 In addition, phenotypic overlaps with cAML have been reported, as some cases of cAML can express CD123 and/or TCL1.…”

“…A review of the literature about CD4-negative HN is complicated by the frequent inclusion in this group of neoplasms of lesions that probably are better classified under different categories such as cAML among others. For example, the case reported by Khoury et al 9 showed only a minority of neoplastic cells positive for TdT (2-7%), whereas expression of CD2, cCD3, the cytotoxic molecule TIA-1 and EBV suggests a diagnosis of NK/ T-cell lymphoma, nasal-type, rather than of HN. In the literature, we found only four cases that could be considered CD4-negative variants of genuine HN.…”

Blastic Plasmacytoid Dendritic Cell Neoplasm Expressing the CD13 Myeloid Antigen

“…Although several lines of evidence regarding the ontogenic origin of plasmacytoid DC suggest a lymphoid origin [5,7,16], other findings have indicated that plasmacytoid DC are related to a myeloid lineage. For example, the transdifferentiation of BPDCN into chronic myelomonocytic leukemia or acute myeloid leukemia has been reported in some cases [17,18]. Interestingly, it has been demonstrated that both common myeloid progenitors and common lymphoid progenitors are able to generate interferon-producing plasmacytoid DC that are able to activate lymphoid-specific genetic programs [19].…”

Plasmacytoid Dendritic Cell Leukemia with Potent Antigen-Presenting Ability

“…Since pDC-characteristic surface phenotypes were not evaluated in leukemic blasts of M4 acute leukemia, it is difficult to say whether or not M4 leukemia and pDCL derived from the common precursor cells in the pDC lineage. However, an association of myelodysplasia with pDCL or a history of myelodysplastic syndrome before pDCL has been reported previously [13, 36, 37]. These reports may suggest a close relationship between M4 acute leukemia and pDCL in case 2.…”