CYTOGENETIC STUDIES IN BURKITT'S LYMPHOMA

Molecular cytogenetics of lymphoma: where do we stand in 2010?

For the past 20 years most malignant lymphomas have been classified as clinicopathological entities, each with its own combination of clinical, morphological, immunophenotypic and molecular genetic characteristics. Molecular and cytogenetic abnormalities can be detected by a wide range of techniques, ranging from conventional karyotyping to single nucleotide polymorphism analysis. In this review, we consider the common genetic abnormalities found in lymphoma and discuss the advantages and disadvantages of individual techniques used in their detection. Finally, we discuss briefly possible novel developments in the field of lymphoma diagnostics.

8;14 chromosome translocation in a negative bone marrow aspirate from a patient with Burkitt's lymphoma

A patient with Burkitt's lymphoma is described who, on presentation, had a bone marrow aspirate which did not show abnormal cells. Cells from the bone marrow were cultured and an 8;14 chromosome translocation was identified. This finding allowed us to upgrade the stage of disease from III to IV with therapeutic as well as prognostic implications.

North american Burkitt-type ALL with a variant translocation t(8;22)

A variant translocation, t(8;22) (q24;q12), was found in bone marrow (BM) and long-term cultured peripheral blood (PB) cells obtained from an American boy with Burkitt-type acute lymphoblastic leukemia (ALL-L3, French-American-British classification). Surface marker studies revealed a monoclonal immunoglobulin A (sIgA) with a lambda chain (74%) on the PB cells in a sample containing 74% blast cells. A table summarizing the cases with variant translocations in Burkitt diseases [Burkitt lymphoma (BL) and ALL-L3] is presented, and review of the published data indicates that, generally, the survival of patients with t(8;22)-type BL and ALL-L3 is short and comparable to that of patients with the more common translocation, t(8;14). There appears to be no relationship between t(2;8) or t(8;22) and a specific heavy-chain sIg. The karyotypes of the BM cells and those of the long-term cultured PB cells, though retaining t(8;22), differed from each other. Chromosomal analyses using cells from long-term culture may reveal karyotypic changes in addition to those seen on direct analysis. The key karyotypic anomaly in Burkitt-type diseases appears to be the breakage of chromosome #8 at band q24.

Burkitt's lymphoma with 2/8 translocation: a case report with special reference to the clinical features

A case of Japanese Burkitt's lymphoma (BL) with a t(2; 8) (p11; q24), a variant translocation in BL, is reported. The patient was a 45-year-old woman in whom a subcutaneous right axillary tumor first occurred. Remission was not achieved despite extensive chemotherapy. Of the four nonendemic BL, two endemic BL, and one nonendemic Burkitt-type acute lymphocytic leukemia (ALL-L3) cases with a t(2; 8) reported so far, including the present case, four (two nonendemic and two endemic) were positive for Epstein-Barr virus-determined nuclear antigen (EBNA) and two revealed extremely high antibody titers against Epstein-Barr virus (EBV), the remaining one not having been tested for EBV. Thus, a possible close relationship between the t(2; 8) and EBV infection has to be considered. The t(2; 8) in nonendemic BL seems to occur more often in adults than in children.

Marker chromosome 14q+ in non-endemic Burkitt's lymphoma

The chromosomal aberrations in tumor cells obtained by bone marrow aspiration from a patient with non-endemic Burkitt's lymphoma (BL) are reported. Twenty percent of the cells contained the marker chromosome 14q+ earlier described in endemic Burkitt's tumors. Other marker chromosomes were dound only in mitoses which did not contain the 14q+.

Karyotypes in infectious mononucleosis

Using a trypsin-Giemsa banding procedure, chromosome analysis was performed on blood from 21 consecutive patients hospitalized for infectious mononucleosis. Mitoses were harvested after 2 and 24 h in vitro incubation without PHA and after 48 h with PHA. No abnormalities were seen.

Simian virus 40-chinese hamster kidney cell interaction. I. Relationship of chromosome changes to transformation

After approximately 20 in vitro passages, Chinese hamster kidney (CHK) cell cultures transformed upon exposure to different strains of SV 40 can show a diploid modal chromosome number of 22 with chromosome counts exclusively or essentially in the diploid range (20-25). In primary culture and at the 5th-7th subculture, tumors produced in nude mice by such cells can display a diploid modal value of 22 chromosomes. Numerical chromosome variations and karyotype abnormalities observed in CHK cells transformed upon infection with SV 40, are apparently indistinguishable from those that can be observed in uninfected CHK cells undergoing "spontaneous"-transformation. These results indicate that polyploidization is not a necessary step either in the process of transformation or in that of tumorigenic conversion with SV 40.

Cytochemical and cytogenetic findings in five human leukocyte long-term cultures (LAHL) of different origin

Five human leukocyte long-term suspension cultures were investigated by means of cytochemical and cytogenetic methods. A striking resemblance in the morphology of these cells originating either from peripheral blood or from spleen of patients with or without hematological disorders was found. Lymphocytic origin of all five cultures is suspected. In the three cultures a diploid karyotype was found with some aberrations. In one culture, derived from the spleen of a patient with panmyelopathy the mosaic 45 XX C -/46 XX was detected. Anomalies of C group chromosomes were the most consistent type of chromosome aberrations in two lines. Both were EBV positive.