Bilateral synchronous tibial periosteal osteosarcoma with familial incidence.

Multifocal or multicentric osteosarcoma (OS) has been described as tumor occurrence at two or more sites in a patient without visceral metastasis. These may be synchronous (more than one lesion at presentation) or metachronous (new tumor developing after the initial treatment). The incidence of multifocal OS has ranged from 1.5 to 5.4% in large series, with the synchronous type being rarer. Similarly, periosteal OS is another rare subtype of surface OS and constitutes less than 2% of all OS. An 11-year-old female was diagnosed with bilateral synchronous tibial periosteal OS, which were confirmed by CT-guided biopsies. After neoadjuvant chemotherapy, the patient underwent a staged wide local resection of the tumors. The defect was reconstructed with a proximal tibial replacement on the left side and autologous bone grafting on the right side. The patient did well after surgery and is free of disease at 5.5 years of follow-up. However, her brother also developed a right tibial periosteal osteosarcoma 4 years after her index surgery. Genetic analysis of blood sample from both patients showed a similar missense mutation in at least one allele of TP53 gene (exon 8). To the best of our knowledge, a case of bilateral 'synchronous' periosteal OS with a familial incidence has not been reported before.

Dicentric (17;20)(p11.2;q11.2): an uncommon cytogenetic abnormality in myeloid malignancies.

We report on two patients with myeloid disorders and complex karyotypes including a dicentric chromosome, dic(17;20)(p11.2;q11.2), resulting in the loss of most of 17p and 20q. The presence of the centromeres of chromosomes 17 and 20 in the dic(17;20), as well as the loss of TP53, were confirmed by fluorescence in situ hybridization. Deletions of 17p and 20q are recurrent abnormalities in hematologic disorders, particularly myelodysplastic syndrome and acute myeloid leukemia). However, a dic(17;20) is an uncommon finding. According to the few reports in the literature, dic(17;20) is associated with an unfavorable prognosis. The key mechanism might be the loss of TP53 as well as other tumor suppressor genes in 20q that may have a critical role in tumor genesis.

Variant acute promyelocytic leukemia translocation (15;17) originating from two subsequent balanced translocations involving the same chromosomes 15 and 17 while preserving the PML/RARA fusion.

Fluorescence in situ hybridization (FISH) analysis of the bone marrow of a 24-year-old man diagnosed with acute promyelocytic leukemia (APL) revealed a variant pattern with one fusion signal instead of the typical two fusions expected with the probe set used. The combined FISH and conventional chromosome analyses suggested that two subsequent translocations had occurred in this patient involving the same chromosomes 15 and 17. As the prognostic outcome in APL is strictly associated with the presence of a PML/RARA fusion, it is useful and necessary to perform both cytogenetic and FISH analyses of a variant t(15;17) to determine the status of the PML/RARA fusion.

Isolated del(14)(q21) in a case of precursor B-cell acute lymphoblastic leukemia.

We present a case of del(14)(q21) as a sole abnormality in a 4-year-old boy diagnosed with precursor B-cell acute lymphoblastic leukemia (pre-B ALL). To our knowledge, this is the first case of isolated del(14)(q21) in pre-B ALL. Two pretreatment bone marrow samples obtained 5 days apart were analyzed by cytogenetics. The G-banded karyotypes of the two samples were similar, differing only in the ratio of normal/abnormal metaphases detected. Both samples showed a del(14)(q21) as the only abnormality. Fluorescence in situ hybridization performed using the probes TEL/AML1 and immunoglobulin heavy chain (IGH) showed no fusion involving the TEL and AML1 genes and only a single IGH signal in 20% of the interphase cells analyzed.

Renal cancer: cytogenetic and molecular genetic aspects.

To date, much progress has been made in the fields of cytogenetics and molecular genetics of renal tumors. The previous and recent findings have delineated the characteristics of the various tumors, particularly the cytogenetic and molecular differences that exist between papillary and nonpapillary clear cell renal cell carcinomas (RCCs). At the same time, new cytogenetic subtypes have emerged [e.g., t(X;1)] in subtypes of RCC, while in others (e.g., Wilms tumors) several new cytogenetic abnormalities and consequent molecular involvement have been found. In addition to Wilms tumor, papillary RCC, and clear-cell RCC, cytogenetic and fluorescence in situ hybridization analyses have been performed on several other tumors of the kidney, including chromophobic carcinoma, metanephric adenoma, collecting duct carcinoma, transitional cell carcinoma, congenital mesoblastic nephroma, and malignant rhabdoid tumors of the kidney. This review is therefore intended to present a concise update on the cytogenetic and molecular data on renal tumors, focusing mainly on the clinical usefulness of the findings reported in the literature.

Exon scanning by reverse transcriptase-polymerase chain reaction for detection of known and novel EML4-ALK fusion variants in non-small cell lung cancer.

Chromosomal inversions within chromosome 2p, resulting in fusions between the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) genes, are a recent focus of treatment options for non-small cell lung cancer. Thirteen EML4-ALK fusion variants have been identified, affecting eight EML4 exons. We have developed an exon scanning approach using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify known and potential variants involving the first 22 EML4 exons. A total of 55 formalin-fixed, paraffin-embedded lung cancer tumors were screened, of which 5 (9%) were positive for EML4-ALK fusions. Four positive cases harbored known fusion variants: variant 3a, 3b, or both in three cases and variant 1 in one case. The fifth positive specimen harbored two novel variants, designated 8a and 8b, involving exon 17 of EML4. Fluorescence in situ hybridization confirmed the presence of EML4-ALK fusions in three of the four RT-PCR-positive specimens with sufficient tissue for examination, and also confirmed absence of fusions in all 19 RT-PCR-negative specimens tested. Immunohistochemistry analysis confirmed ALK protein expression in the sample containing the novel 8a and 8b variants. This RT-PCR-based exon scanning approach avoids the limitations of screening only for previously identified EML4-ALK fusions and provides a simple molecular assay for fusion detection in a clinical diagnostics setting.

Cytogenetics and genetics of human cancer: methods and accomplishments.

Cytogenetic and related changes in human cancer constitute part of a constantly developing and enlarging continuum of known genetic alterations associated with cancer development and biology. The cytogenetic component of this continuum has fulfilled much of its pioneering role and now constitutes a small but dynamic segment of the vast literature on cancer genetics, in which it has played an important if not initiating role. The goals of this article are (a) to address historical and methodological aspects of cancer cytogenetics; (b) to present information on diagnostic translocations in leukemias, lymphomas, bone and soft tissue tumors, and carcinomas; (c) to connect some of these chromosomal aberrations with their molecular equivalents; and (d) to describe anomalies in some solid tumors indicative of the complexity of the genomic alterations in cancer. We also look at a few of the more recent genomic developments in cancer and offer an opinion as to what all these findings add up to.

Poor outcome in a pediatric patient with acute myeloid leukemia associated with a variant t(8;21) and trisomy 6.

RUNX1T1/RUNX1 (formerly ETO/AML1) is a molecular marker that is usually associated with a favorable outcome in both pediatric and adult patients with acute myeloid leukemia (AML). We describe a 10-year-old girl with AML associated with an RUNX1T1/RUNX1 fusion. The patient's karyotype at the time of diagnosis was 46,X,-X,t(4;21;8)(q25;q22;q22),+6. She had an early relapse while being treated on a standard protocol and had significant difficulty in attaining a second remission. She subsequently underwent a matched related donor bone marrow transplant, but a second bone marrow relapse with extensive extramedullary disease followed on day +199. Cytogenetic analysis at second relapse showed evidence of clonal evolution in the form of a highly complex karyotype with numeric and structural abnormalities in addition to the t(4;21;8) and trisomy 6 detected in the diagnostic sample. Trisomy 6 is an uncommon cytogenetic abnormality in myeloid diseases. As a sole abnormality, it has been associated mainly with myelodysplastic syndrome and AML. The presence of this novel variant of t(8;21)(q22;q22) associated with trisomy 6 may have abrogated the usual favorable prognosis associated with RUNX1T1/RUNX1 in AML.

Insertion (12;9)(p13;q34q34): a cryptic rearrangement involving ABL1/ETV6 fusion in a patient with Philadelphia-negative chronic myeloid leukemia.

We report a rare cryptic ins(12;9)(p13;q34q34), a chromosomal abnormality involving the ABL1 (9q34) and the ETV6 (alias TEL; 12p13) genes, detectable only by fluorescence in situ hybridization (FISH), in a patient with Philadelphia-negative chronic myeloid leukemia (CML). Using reverse 4',6-diamidino-2-phenylindole banding on metaphase cells, FISH analysis with BCR/ABL dual-fusion and ETV6 break-apart probes showed that a third ABL signal was inserted into 12p, splitting the ETV6 signal into two adjacent signals. CML patients with an ABL1/ETV6 fusion historically have demonstrated a variable and sometimes transient response to treatment with imatinib mesylate, which was also the case in the present patient.