1/12. Acute monocytic leukemia with a novel 10;11 rearrangement resolved by fluorescence in situ hybridization.fluorescence in situ hybridization analysis in an adult with acute monocytic leukemia revealed the complex nature of a rearrangement between chromosomes 10 and 11, which resulted in disruption of the MLL gene. Using a combination of chromosome 10 and 11 paints, a 10 centromere-specific sequence, and a probe for the MLL locus at 11q23, the rearrangement was deduced to have involved a reciprocal translocation between chromosomes 10 and 11, followed by an inversion within the short arm of the derivative 10. To our knowledge, this novel rearrangement has not been described previously.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/12. MLL/SEPTIN6 chimeric transcript from inv ins(X;11)(q24;q23q13) in acute monocytic leukemia: report of a case and review of the literature.Rearrangements of the MLL gene on chromosome 11, band q23, are one of the most common genetic changes in acute leukemia. Reciprocal translocation is the most common form of MLL rearrangement, and the partner genes in MLL translocation are notably diverse. Involvement of the SEPTIN6 gene on Xq24 in MLL rearrangements occurs very rarely, with only six cases having been documented in the literature. Of note, the MLL/SEPTIN6 rearrangements in these cases were cryptic or complex, and it was shown that the 5'-MLL/SEPTIN6-3' transcript resides on the derivative x chromosome rather than on the derivative chromosome 11 as in the majority of cases of MLL translocations. These observations suggested that MLL and SEPTIN6 reside on their respective chromosome loci in reverse orientation, that is, centromere-to-telomere and telomere-to-centromere, respectively. We here report a case of acute monocytic leukemia with inv ins(X;11)(q24;q23q13) in a 29-month-old child. fluorescence in situ hybridization study revealed the break-apart 5'-MLL segment to be translocated to the derivative x chromosome, and reverse transcriptase-polymerase chain reaction followed by sequencing analysis confirmed the 5'-MLL/SEPTIN6-3' chimeric transcript. This case is the first to provide direct cytogenetic evidence for the salient nature of the MLL/SEPTIN6 rearrangement. We reviewed clinical and cytogenetic features of all cases of 11q23 and Xq22-24 rearrangements reported up to now, including six cases where the involvement of the SEPTIN6 gene was confirmed by molecular techniques.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/12. Relapse as acute monoblastic leukemia (AML-M5) of t(6;9) acute myeloblastic leukemia (AML-M2).Two patients with acute myeloblastic leukemia with t(6;9)(p23;q34) translocation and classified as AML-M2 relapsed as acute monocytic leukemia (AML-M5). trisomy 8 was found associated with t(6;9) at that time in both patients. Such changes in differentiation of leukemic cells have not previously been reported in this subtype of AML and add data favoring the pluripotent nature of the stem cell involved in leukemia with t(6;9).- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/12. Relapse as acute monocytic leukaemia of acute lymphoblastic leukaemia with t(4;11).A young adult suffering from acute lymphoblastic leukaemia with t(4;11) relapsed with features of monocytic leukaemia. This unusual evolution is discussed in relation with the pluripotent nature of t(4;11) leukaemic cells.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/12. Lectin distinction of benign from malignant histiocytes.ricinus communis agglutinin (RCA) staining of malignant histiocytosis (two cases) and tissue infiltrates of monoblastic leukemia revealed two distinct macrophage-histiocyte types: one with cytoplasmic staining (RCA ), the other without (RCA-). RCA cells corresponded to benign-appearing histiocytes without nuclear atypia, whereas RCA-cells were cytologically malignant. In one case of malignant histiocytosis, many RCA-tumor cells were surrounded by a thin cytoplasmic extension of RCA cells, which suggested an interaction between the tumor cells and stromal macrophage-histiocytes. These observations support the view that most benign-appearing histiocytes in malignant histiocytosis are reactive in nature and suggest that RCA staining can be useful in distinguishing between benign and malignant disorders of macrophage-histiocytes.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/12. leukemia cutis in acute monocytic leukemia.We describe the case of a patient with acute monocytic leukemia who demonstrated striking leukemic infiltration of the abdomen. This cutaneous involvement occurred in association with systemic relapse. Histologic examination of a biopsy specimen of a cutaneous lesion showed a diffuse infiltrate of leukemic cells in the dermis. However, blood vessels and skin adnexa were well-preserved, despite the destructive nature of monocytic leukemia.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/12. Acute monoblastic leukemia with a single chromosomal rearrangement involving breakpoints on chromosomes 8 and 16, 46, XX, t(8;16)(p11;p13).We report a case of acute nonlymphoblastic leukemia (M5) with a rare cytogenetic abnormality involving chromosomes 8 and 16, t(8;16)(p11;p13). The leukemic blasts were determined to be monocytic by cytochemical and immunochemical studies. Morphological changes of the leukemic cells in response to phorbol myristate acetate further supported their identification as monocytic in nature. This chromosomal abnormality has apparently been reported only thrice in the literature. Translocation (8;16)(p11;p13), though rare, may be of primary importance in the process of leukemogenesis in some cases of histiocytic/monocytic malignancies.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/12. Extramedullary (skin) presentation of acute monocytic leukemia resembling cutaneous lymphoma: morphological and immunological features.Acute monocytic leukemia has been noted to exhibit a predilection for extramedullary involvement (gums, skin, and lymph nodes) at presentation. More unusual is the occurrence in an extramedullary site in the absence of bone marrow involvement. A case is reported with initial presentation in skin preceding a subsequent evolution to a leukemic phase by one year. The skin tumor was initially diagnosed and treated as a lymphoma. A second skin tumor, biopsied one year later was immunophenotyped as a T cell lymphoma using a screening panel of antisera (OKT4 positive, OKMI negative). Shortly thereafter a monocytic leukemia (M5) was discovered. Using a larger panel of antisera and enzyme markers on the second skin biopsy confirmed the monocytic rather than lymphocytic nature of the skin tumor. This case illustrates the importance of using an expanded panel of monoclonal antisera in certain hematopoietic tumors.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/12. leukemia cutis treated with total skin irradiation.An infant with acute monoblastic leukemia who presented with an extramedullary mass and involvement of the bone marrow, cerebrospinal fluid, and skin is described. After achieving remission, she later developed a relapse that was isolated in the skin. Superficial electron beam irradiation to the total skin surface was administered as therapy for the relapse. She remains in remission 12 months following this treatment. The isolated nature of the skin relapse, in addition to the fact that the relapse did not involve a previously irradiated field, suggests that the skin may have harbored the leukemic cells since the time of diagnosis. Cytogenetic data is presented that lends further support to this hypothesis.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/12. Acute monocytic leukemia cell isoferritin.Ferritin was purified from acute monocytic leukemia cells, and its biochemical and immunological properties were investigated. The iron content of acute monocytic leukemia cell ferritin was extremely low, and this ferritin migrated slightly faster than normal adult liver ferritin on immunoelectrophoresis and polyacrylamide gel disc electrophoresis. isoelectric focusing in polyacrylamide gel showed predominantly acidic isoferritins. This was considered to characterize the nature of isoferritin from normal monocytes or to be the result of neoplastic change of monocytes. Immunologic studies failed to recognized any antigenic differences between isoferritin from acute monocytic leukemia cells and that from normal adult liver. Therefore, selective quantitation of acute monocytic leukemia cell isoferritin, if any in leukemic sera, by means of immunoassay was considered difficult.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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