Sugandhi A. Tharapel

Numerical chromosome abnormalities associated with early clinical stages of gynecologic tumors

Cytogenetic data are presented for 12 ovarian, three endometrial, and one fallopian tube tumors. In 15 of these, primary tumors were analyzed and in one ascites was studied. All specimens were obtained at the time of diagnostic surgery. Trisomy for chromosome 7 was detected in three ovarian and one endometrial tumors. In one case, trisomy 7 was the sole cytogenetic abnormality detected. Three of the four patients with trisomy 7 had early stages of adenocarcinoma. The data suggest that numerical chromosome abnormalities may be common in borderline and in less aggressive gynecologic tumors.

Validation of Primed In Situ Labeling (PRINS) for Interphase Analysis: Comparative Studies with Conventional Fluorescence In Situ Hybridization and Chromosome Analyses

Primed in situ labeling (PRINS) is a rapidly developing new technology with wide ranging clinical applications. To assess the sensitivity, specificity, and accuracy of PRINS, we carried out a retrospective study on cultured bone marrow cells to detect aneuploidy for chromosomes 7, 8, and 12. The results were then compared to the results of previous fluorescence in situ hybridization (FISH) and chromosome analyses (CA). In patients who showed aneuploidy with CA, both FISH and PRINS confirmed the aneuploidy in interphase cells. FISH and PRINS also showed excellent correlation with conventional cytogenetic analysis for the detection of mosaic aneuploidies. However, both FISH and PRINS showed significantly higher sensitivity in the detection of abnormal clones compared to CA. In 9 of the 17 cases, there were no significant differences in the detection rates between the two methods. Based on our studies, we conclude that PRINS is as sensitive as FISH in most cases for aneuploidy detection; and that PRINS, like FISH, is more sensitive than conventional CA for aneuploidy detection.

Rapid identification of marker chromosomes using primed in situ labeling (PRINS)

Primed in situ labeling (PRINS) is a relatively new technology with wide-ranging applications in clinical cytogenetics. Using PRINS, we have identified the chromosomal origin of marker chromosomes in three patients. In the first patient with primary amenorrhea, we were able to confirm the marker chromosome as originating from an X. In the second (prenatal) case, PRINS allowed us to determine rapidly the origin of the marker as a Y chromosome. In the third patient with minor anomalies, the marker was identified as derived from a chromosome 18. In all three cases, application of PRINS permitted us to characterize the marker chromosomes within 1 hour after the slides were prepared. The methodology is simple, has added advantages over conventional fluorescence in situ hybridization (FISH), and can be used as a viable and effective alternative to FISH in clinical cytogenetic diagnosis.

Primed in situ labeling for rapid prenatal diagnosis

OBJECTIVE Our purpose was to assess the feasibility of primed in situ labeling for analysis of prenatal diagnostic specimens. STUDY DESIGN Prenatal diagnostic specimens were chosen at random for analysis without knowledge of clinical indication. Primed in situ labeling with primers for chromosomes 18, 21, X, and Y was performed separate from conventional cytogenetic analyses. All clinical management considerations were based solely on conventional cytogenetic analyses. RESULTS Forty-one samples were analyzed by primed in situ labeling: 35 direct preparations of chorionic villi and 6 uncultured amniotic fluid samples. In all cases analysis confirmed the particular chromosome number determined by conventional cytogenetic analysis. CONCLUSIONS Although conventional metaphase studies remain the standard for prenatal cytogenetic analyses, the preliminary feasibility study finds primed in situ labeling to be a rapid and reliable adjunctive diagnostic technique applicable for prenatal diagnosis in certain clinical situations. Further study is needed to assess the efficacy of primed in situ labeling in comparison to fluorescent in situ hybridization and conventional cytogenetic analyses for prenatal diagnoses.

First trimester chorionic villi sampling and direct chromosome preparations

Chorionic villi sampling was performed on 52 patients prior to elective termination of their pregnancies. Villi were obtained in 42, and direct chromosome preparations were successful in 41 of them. The use of a mixture of 0.075 M potassium chloride and 1% sodium citrate in the ratio of 2:1 for hypotonic treatment and 40% acetic acid for cell dispersal yielded chromosomes with good morphology and G‐bands.

An indolent B-cell lymphoma with t(2;8)(p12;q24) abnormality and absence of C-MYC amplification and TP53 deletion. A new variant?

The translocation between chromosomes 2 and 8, t(2;8), is well known for its strong association with high-grade Burkitt lymphoma. However, the significance of this translocation in indolent lymphoproliferative disorders is not clear. We present the case of a 75-year-old white male with left upper quadrant abdominal pain, splenomegaly, and an elevated white cell count of 30.3x10(9) cells/L (84% large lymphoid cells with scanty cytoplasm and prominent central nucleoli). Immunophenotyping revealed a clonal B-cell population coexpressing CD5, CD19, and CD20 with weak CD23 and CD25 and very weak, restricted, surface lambda. The cytogenetic analysis showed all 20 cells with t(2;8)(p12;q24.3). In addition, four of the 20 cells also showed a second translocation: t(12;17)(p13;q21). Molecular analysis using c-myc and p53 probes showed normal results with no indication of amplification of C-MYC or deletion of TP53. The patient was managed as an indo-lent/low-grade lymphoproliferative disorder with excellent response to eight cycles of fludarabine.