Leukemias are characterized by an idiopathic proliferation of a progenitor cell that is committed to a single cell lineage. However, leukemias with dual-lineage differentiation are being described, especially within the pediatric age group. The authors reviewed 118 cases of adult acute leukemia phenotyped by immunofluorescent flow cytometry; 7 cases demonstrated mixed cell lineage. Immunophenotypically these cases were defined by early B-lymphocyte differentiation (TdT, HLA-DR, and CD19) coexpressed with a myeloid receptor (CD13, CD15, or CD33) on the same leukemic cell. Routine cytochemical evaluation demonstrated punctate positivity of the blasts with naphthol AS-D chloroacetate esterase stain in five of seven cases. Cytogenetic analysis revealed structural abnormalities of chromosome 11 in four of the seven cases. Three of these studies showed a break at 11q23-24, the location of the human proto-oncogene ets-1. Clinically, two of these leukemias represented chronic myelogenous leukemia in blast crisis, and all cases behaved aggressively. The authors' data suggest that mixed lineage leukemias are an identifiable subset of adult acute leukemias and are associated with a poor prognosis.

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

Six patients with Hodgkin's disease (HD) and demonstrable serum antibodies to human immunodeficiency virus (HIV) and two additional patients with HD belonging to HIV-associated high-risk groups but with negative HIV serology were studied. All patients were men and ranged in age from 21 to 45 years. The HIV risk factors included homosexuality (6), intravenous drug abuse (2), and hemophilia A (1). All patients had high pathologically determined stage (one Stage III and seven Stage IV), and bone marrow involvement was observed in five patients with the initial diagnosis of HD based on marrow biopsy in two cases. Four cases were histologically subclassified as mixed cellularity (MC) and three as nodular sclerosis (NS); one patient underwent only bone marrow biopsy and was not subclassified. Histologically all cases were characterized by numerous Reed-Sternberg cells and variants, and with the exception of one case, all had a distinctive decrease in the proportion of reactive background lymphocytes compared with what is usually expected in MC or NS Hodgkin's disease (relative lymphocyte depletion). Flow-cytometric immunophenotypic studies done on cell suspensions from diagnostic lymph node biopsies in four cases showed decreased CD4:CD8 ratios (mean = 1.4) compared with expected values of 4 to 6. The relative lymphocyte depletion observed histologically is probably a reflection of the decreased tissue CD4:CD8 ratios, and this impairment of host immune response may be related to the observed high stage in all eight cases. Patients with high stage HD and the described histologic and immunologic features should be evaluated for the presence of HIV infection.

The case is described of a 62-year-old man with a 10-year history of hairy cell leukemia (HCL) who subsequently had a large-cell anaplastic or so-called Ki-1-positive lymphoma. Immunocytochemical staining of the lymphomatous node revealed positivity for Ki-1 (CD30) and epithelial membrane antigen in the tumor cells, and flow cytometric analysis showed simultaneous expression of Leu M5 (CD11c) and Leu 14 (CD22). Although HCL has been reported to coexist with both Hodgkin's disease and non-Hodgkin's lymphoma, the authors believe this is the first case in which a Ki-1-positive lymphoma developed in a patient with HCL. The clinicopathologic and immunologic features of both entities are discussed, as is the association of HCL with other neoplasms.

CD56(+) 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.