Pleural effusion in a child with a correctly placed ventricle-peritoneal shunt.

Pleural effusions in children (PE) due to ventricle-peritoneal shunt (VPS) is very rare, with few cases reported. We present a new case of an infant with VPS who had a massive hydrothorax not associated with misplacement or migration of the distal catheter or with ascites. After the evacuation of the PE we managed the patient by adjusting the pressure of the adjustable valve (AV). Sequential thoracic ultrasounds showed a satisfactory outcome. We review the literature thoroughly and describe the possible pathophysiological mechanisms.

Molecular Cytogenetic Characterization of a Karyotype of a Female Patient with Secondary Amenorrhea with a Cell Line Showing 46,X,+mar.

OBJECTIVES: Disorders of sex development (DSD) include a group of conditions in which genotypes do not correlate with the typical male and female phenotypes. Numerical and structural abnormalities involving both autosomes and sex chromosomes have been observed in DSD. Specifically, deletions, duplications, and translocations involving specific genes as well as point mutations and less common aberrations have been implicated in the pathogenesis of these conditions. Finally, recent advances in analytical tools, namely chromosomal microarrays and sequencing methods, have greatly enhanced the precision with which DSD are genetically characterized and phenotypically correlated. Herein we report a case of a 24-year-old female patient who presented with secondary amenorrhea. Cytogenetic studies of her peripheral blood showed an abnormal clone with 45,X in three cells and the other was initially observed by chromosome analysis as 46,X,+mar in 27 cells. Molecular cytogenetics were performed to characterize the marker chromosome that showed two copies of the SRY, two copies of the heterochromatin Yq12, and two copies of the Y centromere Yp11.1-q11.1 on the marker chromosome, resulting in the identification of an isodicentric Y chromosome. Females with a 46,XY karyotype have gonadal dysgenesis and typically present as mosaic, along with a 45,X cell line. Some show small deletions of the short arm of the Y chromosome. Further studies based on the clinical picture, as well as possible prophylactic gonadectomy due to an increased risk of gonadal malignancy, gonadoblastoma or dysgerminoma, are suggested. Genetic counseling was recommended.

Cryptic ins(4;11)(q21;q23q23) detected by fluorescence in situ hybridization: a variant of t(4;11)(q21;q23) in an infant with a precursor B-cell acute lymphoblastic leukemia report of a second case.

We report the chromosomal findings in a 4-year-old female with precursor B-cell acute lymphoblastic leukemia (ALL). The diagnostic karyotype showed an isochromosome 7q, i(7)(q10), as well as questionable rearrangements on 9p and 11q. Fluorescence in situ hybridization (FISH) studies on both interphase and metaphase cells using the MLL "break-apart" and the centromeric chromosome 4 probes were instrumental in the characterization of an MLL gene rearrangement, which was cryptic by conventional cytogenetic analysis. Specifically, the FISH pattern was consistent with an insertion of the 5' region of the MLL gene into chromosome 4 at band q21, most likely a variant t(4;11)(q21;q23). This is the second case of FISH detection of an ins(4;11) in ALL. Our case exemplifies the importance of FISH in the further characterization of precursor B-cell ALL cases without any apparent prognostically significant chromosomal abnormalities.

Molecular and cytogenetic characterization of a novel rearrangement involving chromosomes 9, 12, and 17 resulting in ETV6 (TEL) and ABL fusion.

We performed chromosome analysis on the bone marrow of a patient with BCR/ABL negative chronic myelogenous leukemia (CML). By interphase fluorescence in situ hybridization (FISH), an extra ABL signal was present in interphase nuclei and appeared to be located at 17p in the metaphase cells. Chromosome analysis showed a subtle abnormality at 17p13 and 12p13 but no visible rearrangement at 9q34 (ABL). Additional FISH experiments disclosed a rearrangement between the short arms of chromosomes 12 and 17 at approximately bands 12p13 and 17p13, respectively. In addition, subtelomeric FISH analysis confirmed the presence of terminal 12p at 17p13 and showed terminal 9q34 to be intact on each chromosome 9. Taken together, these results indicated a rearrangement involving chromosomes 9, 12, and 17 that suggested the possibility of juxtaposition of part of the ETV6 (also known as TEL) locus (12p13) with a portion of ABL (9q34) together at 17p13. The ETV6/ABL fusion was confirmed by RT-PCR, which showed that the first 5 exons of ETV6 were fused in frame with ABL at exon 2. Wild-type ETV6 and ABL were also expressed, in accordance with the FISH results that showed no loss of the second ETV6 or ABL allele.

Identification of a novel amplicon at 1q31 in pancreatic cancer cell lines.

Pancreatic adenocarcinoma is a highly lethal malignant tumor that is increasing in frequency, now ranking fifth in the United States as a cause of death attributed to cancer. Patients with pancreatic carcinoma have one of the poorest prognoses of all cancer patients, with the number of deaths being approximately 75% of the total number of cases. The use of comparative genomic hybridization (CGH) has gained widespread use in the study of some types of solid tumors, and it seems to be a very good approach in pancreatic adenocarcinomas, in which just a few cases have been studied cytogenetically, mostly owing to the fact that these tumors are very difficult to grow in culture. Fourteen pancreatic cancer lines were examined with CGH. In 11 of these lines, we found an amplicon at 1q31, not previously reported in pancreatic cancer. More studies need to be done in primary tumors to determine the involvement of 1q31 in this type of tumor.

Cytogenetic and molecular analysis of an unusual case of acute promyelocytic leukemia with a t(15;17;17)(q22;q23;q21).

We present a 52-year-old female with a clinical history of acute myelocytic leukemia, probable acute promyelocytic leukemia (APL). Flow cytometry results were somewhat unusual. Specifically, the promyelocytic population showed partial positivity for antigens not usually expressed in APL (HLA-DR and CD117). The interpretation of these results was that the abnormal population contained a proportion of very early promyeolocytes that had not completely lost all their "precursor" antigens. Cytogenetic analysis of a bone marrow aspirate showed a t(15:17;17)(q22;q23;q21) in all cells analyzed. Fluorescence in situ hybridization (FISH) analysis using the PML-RARA DNA probe showed a positive signal pattern (fusion) in 100% of 200 total interphase and metaphase cells examined, confirming the presence of the PML-RARA rearrangement. Multicolor FISH, which produces 24 colors to differentiate all chromosomes in a single hybridization, was applied. This study confirmed the cytogenetic interpretation of the rearrangement. No material from any other chromosome was detected on the second smaller derivative chromosome 17. Additional studies using the RARA(17q21) break-apart DNA FISH probe showed that 17q21 (RARA) was not rearranged on the derivative chromosome 17 that received the q22-->qter segment from chromosome 15. The RARA locus on the smaller derivative 17 was the allele involved in the fusion in this three-way rearrangement. The signal pattern was consistent in 100% of interphase and metaphase cells scored. This unusual t(15;17;17) prompted us to investigate further using reverse-transcription polymerase chain reaction with primers from the 3' and 5' regions of both the RARA and PML loci. These studies showed that the PML-RARA fusion was present, but the complementary fusion RARA-PML, which is usually detectable, was absent. The patient is responding well to standard treatment protocols.

A case of infantile acute lymphoblastic leukemia presenting with rearrangement of MLL at 11q23 and apparent insertion or translocation at 10p12.

We report the case of an 11-month-old patient with a clinical diagnosis of infantile acute lymphoblastic leukemia and an MLL (11q23) rearrangement in 69% of nuclei, revealed with interphase fluorescence in situ hybridization (FISH). Routine chromosome analysis of the bone marrow showed a very subtle rearrangement involving the short arm of chromosome 10 and the long arm of chromosome 11 in the abnormal cells. To clarify the nature of this rearrangement, we hybridized the MLL break-apart probe to previously G-banded slides. The rearrangement was interpreted as a small inversion within the band 11q23, separating the 5' MLL from the 3' MLL region. This segment on the long arm of chromosome 11 containing the rearranged MLL locus was either inserted in or translocated to the short arm of chromosome 10 at approximately band 10p12. The inversion affecting MLL may have followed insertion or preceded it. Molecular characterization of this rearrangement was not possible, due to limited sample material. There have been previous reports of rearrangements of MLL with the MLLT10 (alias AF10) gene locus at 10p12, including an interstitial inverted insertion of 11q13q23 in one case and insertion of 11q14q23 at 10p12 in another. These both resulted in a large derivative chromosome 10 and transcription of an MLL/MLLT10 fusion product. To our knowledge, the novel and cryptic rearrangement detected in our patient has not been described previously. A follow-up study of the patient's bone marrow at the end of induction therapy showed no morphologic evidence of residual leukemia and both FISH and chromosome analyses were normal.