The cytogenetics of solid tumors. Relation to diagnosis, classification and pathology

Chromosome Changes in Renal Cell Carcinoma

Cytogenetic studies have provided a great deal of useful information about the biology and diagnosis of renal cell tumors. Particularly papillary and non-papillary tumors seem to be characterized by different cytogenetic patterns. We report the cytogenetic and histologic analysis of 16 renal tumors, 5 of which showed clonal chromosome changes. Most had chromosome abnormalities which have so far been described as specific of particular histopathologic subgroups.

Detection of chromosomal aberrations in renal tumors: a comparative study of conventional cytogenetics and virtual karyotyping with single-nucleotide polymorphism microarrays

CONTEXT

-Renal epithelial neoplasms have characteristic chromosomal imbalances, and we have shown previously that virtual karyotypes derived from single-nucleotide polymorphism microarrays can be performed on formalin-fixed, paraffin-embedded tissue.

OBJECTIVE

-To perform a direct comparison of virtual and conventional karyotypes to evaluate concordance of results.

DESIGN

-Twenty archival formalin-fixed, paraffin-embedded tumor samples with preexisting, conventional cytogenetic results were analyzed with Affymetrix 10K 2.0 or 250K Nsp single-nucleotide polymorphism microarrays.

RESULTS

-Nineteen samples yielded adequate virtual karyotypes for interpretation. Eight samples showed complete agreement between the 2 techniques, and 8 samples showed partial agreement. The disease-defining lesions (eg, loss of 3p for clear cell carcinoma) were identified in all 19 cases by virtual karyotypes and in 15 cases by conventional karyotypes. Virtual and conventional karyotypic findings were concordant in the identification of these disease-defining lesions in 86% (13 of 15) of cases. In 3 cases, virtual karyotypes identified lesions consistent with the morphologic diagnosis, whereas the conventional karyotypes were unsuccessful because of insufficient tumor representation or stromal overgrowth. Two cases with acquired uniparental disomy were identified by single-nucleotide polymorphism arrays, and 5 cases with translocations were identified by conventional karyotype.

CONCLUSIONS

-Our results show that both techniques are able to identify the characteristic chromosomal abnormality for renal tumor subtypes in most cases. Discrepancies can be explained by inherent limitations of each technique, inadequate tumor sampling, and tumor heterogeneity. We conclude that virtual karyotyping is a robust alternative to conventional cytogenetics for the evaluation of chromosomal anomalies in formalin-fixed, paraffin-embedded tissues from renal epithelial neoplasms.

Cytogenetic findings, Trp53 mutations, and hormone responsiveness in a medroxyprogesterone acetate induced murine breast cancer model

Medroxyprogesterone acetate (MPA)-induced mammary carcinomas express high levels of estrogen (ER) and progesterone receptors (PR) and when transplanted in syngeneic mice they show a progestin-dependent (PD) growth pattern. By successive transplantation, progestin-independent (PI) variants were generated and showed a different response to antihormone therapy. A diploid chromosome number (2n=40) was found in three of five PD tumors, with numbers in the triploid to tetraploid range in the other two. Some PI tumors were diploid, but most were aneuploid (8 of 12 tumors). The most frequent alterations found in PD and PI tumors were gains of chromosomes 3, 4, and 6 and losses of chromosomes 16 and X. Chromosomes 4 and 7 were involved in translocations in three of the four tumor families studied. single-strand conformation polymorphism analysis revealed a point mutation on the Trp53 gene in one of the PD tumors; this showed a stable diploid karyotype, suggesting that mutated Trp53 is not uniquely involved in chromosome instability. We have shown that hormone independence may be acquired without changes in ploidy, suggesting that the increase in ploidy is favored by successive transplantation. In our model, diploid tumors responded to hormone treatment but aneuploid tumors were either responsive or not.

Constitutional genomic instability, chromosome aberrations in tumor cells and retinoblastoma

Although retinoblastoma (Rb) is initiated as a result of biallelic inactivation of the RB1 gene, additional genetic events (M3) in tumor cells are indicative of their role in the full transformation of retinal cells. We investigated the constitutional genetic instability by fragile site (FS) expression studies and checked its relationship with loci of tumor cytogenetics in a series of 36 retinoblastoma patients (34 nonfamilial and 2 familial cases). Tumor cytogenetics revealed -13/+13, del/t(13)(q14) (50%), +1/del/t(1p/q) (65%), +6/i(6p) (60%), and del(16)(q13)/(q22 approximately q23) (60%). Conventional cytogenetics in leukocytes revealed constitutional del(13q14) in five unilateral Rb (URB) and one trilateral Rb (TRB). Constitutional del(16)(q22) and t(6;12) were also identified in two cases. Constitutional FS analysis showed a significant increase in the cellular fragility, with high prevalence at 13q14, 3p14, 6p23, 16q22 approximately q23, and 13q22 loci in retinoblastoma patients (P<0.05). Patients with constitutional del(13)(q14) demonstrated higher fragility than those with normal constitution. A strong correlation between loci of constitutional FSs and loci of recurrent chromosomal abnormalities in tumors strengthen and support the proposal that FS loci present as inherent genomic instability in retinoblastoma. The chromosomal changes and resultant genetic mutations, along with RB1 mutation events, probably contribute synergistically to the development and progression of Rb malignancy. Implementation of fluorescence in situ hybridization to nonfamilial Rb on a large scale (113 cases) could detect constitutional RB1 deletion in 12.3% of cases, with equally higher incidence in URB (14.7%) and bilateral Rb (13.6%), demonstrating that the true prevalence of patients with predisposition to RB1 mutation in sporadic URB is definitely higher in our populations. Also, higher incidence of constitutional RB1 deletion mosaicism in unilateral than in bilateral Rb indicates that the constitutional genetic mosaicism in URB should be given serious consideration during genetic counseling.

Distinct MDM2 and P14ARF expression and centrosome amplification in well-differentiated liposarcomas

Well-differentiated liposarcomas (WDLs) are common soft-tissue tumors in adults. They are characterized by large marker chromosomes and/or ring chromosomes containing 12q-derived sequences in which MDM2 is consistently amplified. WDLs are subdivided into two subtypes according to their karyotype. Type D cells exhibit a near-diploid karyotype, with very few or no chromosome changes. Type H cells exhibit a near-tetraploid karyotype and many structural changes. Expression of P14ARF, MDM2, and TP53 proteins was assayed in the two WDL subtypes to establish whether distinct expression profiles correlated with cell ploidy. Although a transcriptionally functional TP53 was present in most tumors independent of their karyotype, type H cells were characterized by high levels of P14ARF and MDM2 proteins. Although amplified within similar chromosome markers in type D tumors, MDM2 did not appear to be overexpressed. In addition, it was present as a C-terminal truncated protein, indicative of alternatively spliced variants of MDM2 mRNA. As the existence of karyotypically distinct tumors could result from alterations of the mitotic machinery, we investigated the centrosome behavior in the two WDL subtypes. Centrosome amplification occurred in WDL tumors types H and D independent of their ploidy status. Moreover, no functional centrosome difference was found between the two tumor subtypes.

Karyotypic evolution of four novel mouse mammary carcinoma cell lines. Identification of marker chromosomes by fluorescence in situ hybridization

We studied the karyotypes of four different mammary carcinoma cell lines derived from a medroxy-progesterone acetate (MPA)-induced mouse mammary carcinoma using G-banding and fluorescence in situ hybridization. All the cell lines showed the same four marker chromosomes (M1-M4) as the parental tumor and also acquired new markers. M1 and M2 are Robertsonian translocations between chromosomes 1 and 10 and 2 and 17. M3 is an acrocentric marker derived from chromosomes 4, 5, and 12; M4 is derived from chromosomes 6 and 8. The parental tumor disclosed a modal number of 39, with a trisomy of chromosomes 3, 4, 10, and 11 and monosomies of 9, 13, and 16. MC4-L1 and MC4-L3 lines had a chromosome number similar to that of the parental tumor in early passages, which increased to the triploid range in late passages. MC4-L5 showed a near-diploid modal number in both early and late passages. MC4-L2 cells had a high chromosome number even in early passages. To our knowledge, this is the first study in which a complete characterization of the cytogenetics of murine mammary carcinoma cell lines and of their parental tumor is described. No associations between changes in ploidy, invasiveness, or hormone dependence were found. Conversely, the presence of one exclusive marker chromosome, a translocation between chromosomes 1 and 18 (M5), in the most aggressive and in vivo hormone-independent line suggests that this rearrangement may be associated with these biologic features. The constant presence of common marker chromosomes in both the parental tumor and the derived cell lines suggests that they are involved in the maintenance of this tumor phenotype.

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.

Synovial sarcoma of the pleura: a clinical and pathologic study of three cases

Synovial sarcomas are rare soft tissue malignancies that most commonly affect the extremities in the vicinity of large joints. These malignancies typically occur in adolescents and young adults between the ages of 15 and 40 years.(1,2) Historically they are believed to originate from primitive pluripotent mesenchyme capable of synovial differentiation. This belief is consistent with the malignancy's origin from sites devoid of normal synovium, such as the pleural cavity. A variety of pleural cavity sarcomas have been described, including liposarcoma,(3) chondrosarcoma,(4) osteosarcoma,(5) and malignant schwannoma.(6) Pleural synovial sarcoma, however, is a much rarer entity. In fact, pleural synovial sarcoma was first described only 6 years ago(7) and has not yet been reported in the surgical literature. Because of its rarity, pleural synovial sarcoma is often mistaken for the histologically similar malignant mesothelioma, the most common of the pleural neoplasms. This is a critical distinction, because synovial sarcoma may be extremely aggressive. Studies in the last 10 years have shown it to be extremely sensitive to ifosfamide-based chemotherapy, and survival of patients with synovial sarcoma has recently increased with chemotherapy, with 5-year survivals now as high as 57%.(8-10) In this report, we describe 3 cases of synovial sarcoma of the pleura. Clinical findings are correlated with pathologic features, including immunohistochemical stains and fluorescence in situ hybridization (FISH) for the identification of the diagnostic chromosomal translocation, t(X;18)(p11.2;q11.2). This delineation of the clinical and pathologic aspects of this rare, newly recognized tumor should increase awareness among the surgical community.

Tumor progression: a brief historical perspective

It has long been known that tumors become more clinically and biologically aggressive over time. This has been termed 'tumor progression' and includes, among other properties invasion and metastasis, as well as more efficient escape from host immune regulation. Since 1960, first cytogenetics and then molecular techniques have shown that tumors expand as a clone from a single altered cell, and that clinical 'progression' is the result of sequential somatic genetic changes, generating increasingly aggressive subpopulations within the expanding clone. Multiple types of genes have been identified, and they differ in different tumors, but they provide potential specific targets for important new therapies.

Primary monophasic synovial sarcoma of the pleura: five cases confirmed by the presence of SYT-SSX fusion transcript

This study reports five cases of primary pleural monophasic synovial sarcomas and assesses the role of the SYT-SSX fusion transcript in the differential diagnosis. Patients had a mean age of 47 years with no gender predilection. Chest pain and pleural-based masses with effusions characterized the clinical presentations. Each patient underwent a complete surgical resection of the mass. The mean follow-up was 9 months, available in four patients. They were all alive, with no evidence of disease. Histologically, neoplasms were composed of densely packed fusiform cells focally alternating with less cellular areas. No epithelial differentiation was identified at the hematoxylin and eosin level. Keratin and epithelial membrane antigen reactivity was focal and present in four and two tumors, respectively. There was no immunoreactivity for CD34. RT-PCR studies for the presence of a SYT-SSX1 or SYT-SSX2 fusion transcript were positive in every tumor. In comparison, 10 localized fibrous tumors were immunohistochemically negative for keratin and epithelial membrane antigen and positive for CD34. A SYT-SSX fusion transcript was not identified in any of five localized fibrous tumors tested. Identification of the synovial sarcoma-specific chimeric transcript (SYT-SSX1 or SYT-SSX2), in conjunction with immunoperoxidase studies, can be extremely helpful in identifying cases of pleural monophasic synovial sarcoma.

[Monoclonal gammopathies of undetermined significance]

INTRODUCTION

Monoclonal gammopathy of undetermined significance is an asymptomatic disorder associated with serum monoclonal immunoglobulin spike. Its incidence is about 1% in patients of 50 years of age, and rapidly increases in elderly patients.

CURRENT KNOWLEDGE AND KEY POINTS

Within the 20 years following diagnosis, about 25% of patients will evolve towards either multiple myeloma (for patients with IgG or IgA) or malignant lymphoproliferative disorder (for patients with IgM). Definition, circumstances associated with a transient monoclonal spike, and currently available parameters used for differential diagnosis with either multiple myeloma or malignant lymphoproliferative disorder are successively discussed. One part of the most usual biological parameters is of prognostic value, and is reviewed in more detail. Recent data concerning immunophenotype, cytogenetics and molecular biology of plasma cells reinforce the link between the asymptomatic condition and multiple myeloma. In monoclonal gammopathy of undetermined significance, some plasma cells resemble normal or reactive plasma cells, whereas others mimic those found in multiple myeloma.

FUTURE PROSPECTS AND PROJECTS

The most recent biological data are also discussed in order to evaluate whether some would help to discriminate those patients who will remain asymptomatic lifelong from those who will evolve towards multiple myeloma.

Comparative genomic hybridization reveals novel chromosome deletions in 90 primary soft tissue tumors

Comparative genomic hybridization (CGH) was used to detect chromosomal gains and losses in a series of 90 frozen soft tissue primary tumors (STTs), all untreated. The material consisted of 69 malignant sarcomas, including 20 malignant fibrous histiocytomas (MFH), 23 liposarcomas (LPS), 6 leiomyosarcomas (LMS), 4 synovial sarcomas, 4 primitive neuroectodermal tumors (PNETs), and various others subtypes, in addition to 21 benign tumors. Within the benign tumors, only 2 of the 3 schwannomas showed genetic changes. In malignant sarcomas, genetic changes were detected in 64 of the 69 samples analyzed (92%), with a mean of 4.5 per sample (range 0-10). Gains and losses on chromosome 13 were observed in 32% of the sarcomas with genomic imbalance. Recurring low-level copy number increases were found at new sites on chromosomes 7 (6 MFH samples, 30%) and 8 (10 LPS samples, 43%), the minimal common regions being 7p15-pter and 8q24. No new recurring high-level amplifications were found. Surprisingly, losses of DNA sequences were more frequent than gains; particularly, losses were the main feature in LMS, with highly recurrent common minimal losses at 11q14-qter and 13q21-q22 (4 samples, 66%, and 5 samples, 83%, respectively). Losses of chromosome 2 sequences (minimal common regions at 2p24-pter and 2q32-qter) were observed in 50% of the MFH analyzed. New recurrent losses of whole or part of chromosome 14 were found in 57% of the pleomorphic LPS (PLPS) analyzed. This study uncovers new clues for the diagnosis of malignant STTs and shows the importance of deletions as events in the early steps involved in the tumorigenesis of STTs.

Computer-assisted cytogenetic analysis of 51 malignant peripheral-nerve-sheath tumors: sporadic vs. neurofibromatosis-type-1-associated malignant schwannomas

Cytogenetic studies in small groups of patients with malignant peripheral-nerve-sheath tumors (MPNST) revealed complex karyotypes with no consistent changes. A computer-assisted cytogenetic analysis using a cytogenetic database was performed to determine recurrent cytogenetic alterations in 51 MPNSTs (44 from the literature and 7 new cases) and to allow direct cytogenetic comparison between NF-1-associated and sporadic MPNSTs. Significant loss (p < 0.05) was observed in the chromosomal regions 9p2, 11p1, 11q2 and 18p1. Also, loss in 1p3, 9p1, 11q1, 12q2, 17p1, 18q1-q2, 19p1, 22q1, X and Y was detected. Gain of chromosomal material was found in chromosome 7, especially 7q1 (p < 0.05). Most involved breakpoints were: 1p13, 1q21, 7p22, 9p11, 17p11, 17q11, 22q11. Cytogenetic differences between NF-1-associated and sporadic MPNSTs included a relative loss of chromosomal material in NF-1-associated MPNSTs in 1p3, 4p1 and 21p1-q2 and a relative gain in 15p1-q1. Differences in breakpoints between the NF-1 associated and the sporadic MPNST group were observed in 1p21-22 (28% of NF-1 vs. 0% of sporadic MPNSTs), 1p32-34 (17% vs. 0%), 8p11-12 (7% vs. 27%) and 17q10-12 (24% vs. 7%). This approach, in which the cytogenetic results of various reports are combined, shows that losses in 9p2 and gains in 7q1 could be of oncogenetic importance in MPNSTs. Loss of 17q1, on which the NF-1 gene has been located (17q11.2), is not a common cytogenetic finding in NF-1-associated MPNSTs. The observed differences between NF-1-associated and sporadic MPNSTs might reflect different oncogenetic pathways.

A molecular cytogenetic study of chromosome 3 rearrangements in small cell lung cancer: consistent involvement of chromosome band 3q13.2

To more precisely determine the nature of chromosome 3 rearrangements in small cell lung carcinomas (SCLCs), we have applied molecular cytogenetic technologies to a newly characterized SCLC tumor and five SCLC cell lines. Fluorescent in situ hybridization, chromosome microdissection, and, on the previously uncharacterized tumor, spectral karyotyping was utilized to determine chromosome 3 rearrangements. In all cases, our studies were performed on previously G-banded chromosomes in a sequential manner to facilitate a direct comparison. A consistent breakpoint on the long arm of chromosome 3 at band 3q13.2 was identified in all six tumors. This breakpoint was commonly the result of complex chromosomal rearrangements. Loss of the entire short arm of a chromosome 3 was noted in all six tumor cultures. Two of these cell lines had two sublines, one of which contained a 3q13.2 rearrangement and the other of which contained a chromosome rearrangement that resulted in loss of a chromosome 3 short arm. This consistent rearrangement at chromosome band 3q13.2, as demonstrated by molecular cytogenetic methods, may indicate the location of a gene important in the tumorigenesis of SCLC.

Concurrent cytogenetic, interphase fluorescence in situ hybridization and DNA flow cytometric analyses of a carcinoma ex-pleomorphic adenoma of parotid gland

We report the cytogenetic, fluorescence in situ hybridization (FISH), and DNA ploidy analyses of a high grade carcinoma ex-pleomorphic adenoma of the submandibular gland. Our overall combined analyses showed a marked DNA aneuploidy and numerical abnormalities involving all chromosomes. Cytogenetic analysis revealed a near tetraploid modal chromosomal number with tetraploid loss of chromosomes Y, 1, 6, 9, 11, 14, 15, 17, and 19-21 and hypertetraploid gain of chromosomes 7, 8, and 22. The structural abnormalities included der(1;14)(q10;q10), del(6)(q15q34), +del(6)(q15q34), +der(8) t(1;8)(q12;q12.2),der(9;19)(q10;q10),add(14)(p11.2),i(20)(q10),der(21) t(8;21)(q11.2;q22.3),+der(21)t(8;21) (q11.2;q22.3). Interphase FISH of the primary and short-term cultured cells using directly labeled pericentromeric probes for chromosomes 6-12, 17, 18, and Y resulted in alterations corresponding to the cytogenetic findings. DNA ploidy analysis of both the primary and cultured tumor cells showed a hyperdiploid stemline with DNA indices of 2.6. The results indicate that: (1) marked numerical, structural chromosomal, and DNA content abnormalities are present in this tumor; and (2) alteration at 8q and 6q regions, together with previous results, suggest an association between these events and the development and/or progression of this tumor.

Detection of trisomy 7 with fluorescence in situ hybridization and its correlation with DNA content and proliferating cell nuclear antigen-positivity in prostate cancer

The authors applied fluorescence in situ hybridization (FISH), using specific DNA probes for chromosome 7, to routine paraffin-embedded tissue sections obtained from 35 radical-prostatectomy specimens. Proliferative activity was also evaluated using static cytometry to assess DNA content and immunohistochemistry for proliferating cell nuclear antigen (PCNA) positivity. These results were correlated with each other and with the morphologic parameters. The presence of three or more of chromosome 7 was observed in 71% of the cases, as was a high S phase, with a triploid prevalent DNA content and a PCNA index above mean value in 66% of the cases. No correlation was detected between these findings and histologic grade; conversely, there was a significant correlation with stage (chi-square = 5.33; p = 0.021). From these results, the authors maintain that the presence of an extra chromosome 7-correlated in most cases with an increase in cell kinetics and an advanced stage-may be an additional prognostic marker of aggressive behavior.

DNA ploidy and cell-cycle analysis in intracranial meningiomas and hemangiopericytomas: a study with high-resolution DNA flow cytometry

Although various DNA flow-cytometric studies have been performed on meningiomas, the role of DNA ploidy and the S-phase fraction (SPF) in predicting biological tumor behavior remains unresolved. Discrepant results in earlier studies might be due to different preparing, staining and measuring techniques; different quality standards; and lack of sophisticated computer software. In this study, high-resolution DNA flow cytometry using the DNA-specific dye DAPI (4', 6'-diamidino-2-phenylindol) was performed on stored frozen tissue from 128 microsurgically resected meningiomas and 7 hemangiopericytomas, including 17 recurrent meningiomas and 4 recurrent hemangiopericytomas. The computer software Multicycle 2.5 was used to determine the ploidy level and to perform cell-cycle analysis. DNA aneuploidy and SPF were significantly higher in atypical, anaplastic and recurrent meningiomas and correlated well with histopathological features such as focal necrosis, infiltration of dura mater and mitotic activity. Among 128 meningiomas, 42 had additional DNA aneuploid stem lines. No association between hypo- and hyperploidy and either histological subtype or clinical outcome was found. In 7 hemangiopericytomas, SPF was significantly higher compared to the benign meningioma group, while only 1 tumor was aneuploid. In all 42 DNA aneuploid tumors, cell-cycle analysis was performed separately for the euploid and aneuploid stem lines. The proliferation parameters (SPF, G2/M phase) were significantly higher in the DNA aneuploid stem lines. DNA ploidy and SPF are thus useful indicators of different biological behavior within identical histological subgroups in meningiomas.

Expression of proliferation associated antigens and detection of numerical chromosome aberrations in primary human liver tumours: relevance to tumour characteristics and prognosis

AIMS

To assess cell proliferation and the presence of numerical chromosome aberrations involving chromosomes 1 and 8 in benign and malignant liver tumours.

METHODS

Cell proliferation was studied immunohistochemically in paraffin wax embedded material from 62 primary liver tumours (20 hepatocellular carcinomas, 16 cholangiocellular carcinomas, 15 liver cell adenomas, 11 focal nodular hyperplasias), and the results were compared with histological characteristics and clinical data. Copy numbers of chromosomes 1 and 8 were assessed by interphase fluorescence in situ hybridisation (FISH) with satellite probes in fresh tumour material.

RESULTS

The expression of proliferation associated antigen Ki67, using the monoclonal antibody MIB-1, and proliferating cell nuclear antigen (PCNA), using the antibody PC10, was found to be significantly higher in malignant versus benign liver tumours. Neither Ki67 nor PCNA expression were independent prognostic parameters. However, there was a tendency for a worse outcome (survival < 12 months) for patients with a high MIB-1 labelling index (> 20%) compared with patients having the same tumour stage and a low MIB-1 index. Aneusomy for chromosomes 1 and 8 was demonstrated by FISH in malignant tumours (six of seven hepatocellular carcinomas, four of five cholangiocellular carcinomas) but not in benign tumours (none of nine) or non-neoplastic liver (none of nine).

CONCLUSION

Both the determination of the proliferating cell fraction and FISH analysis are useful for distinguishing hepatocellular carcinoma from liver cell adenoma or focal nodular hyperplasia; high fractions of proliferating cells are predictive of an early relapse.

Cytogenetic abnormalities related to histopathologic grade of astrocytic tumors

Cytogenetic analysis was performed on 7 low-grade astrocytomas, 10 anaplastic astrocytomas, and 14 glioblastomas. Abnormal chromosome numbers were noted in all cases of high-grade astrocytomas but were rarely noted in low-grade astrocytomas (28%). The most consistent changes in high-grade astrocytomas were complete loss of chromosome 10 (61%), gain of chromosome 7 (56%), and loss of chromosome 17 (28%). Certain structural abnormalities, such as marker chromosomes and double minutes (33%), and the deletion and translocation of chromosomes 1 (33%) and 17 (17%), were also noted. These results indicate that changes in the number and/or structure of chromosomes with related inactivation of tumor suppressor gene or oncogene activation might play a critical role in the formation and anaplastic progression of astrocytic tumors.

Increased spontaneous formation of micronuclei in cultured fibroblasts of first-degree relatives of familial melanoma patients

The phenomenon of spontaneous increased micronuclei and enhanced UV-sensitivity, which is known for familial cutaneous malignant melanoma (CMM) patients, could be demonstrated again in fibroblasts of 17 familial CMM patients. In order to determine if close relatives of familial CMM patients show both a comparable spontaneous chromosomal instability and enhanced UV-sensitivity, cultured fibroblasts of 24 healthy, first-degree relatives of patients with familial malignant melanoma were investigated. The cytokinesis-block micronucleous technique was used to detect enhanced chromosomal instability. Fibroblasts of the investigated relatives showed a significantly increased spontaneous formation of micronuclei, in comparison to 19 healthy controls, but no enhanced UV-sensitivity was evident. We conclude that chromosomal instability might be a hereditary trait and a causative factor in developing familial malignant melanoma. This supports the concept of a genetic predisposition to familial CMM and may help to identify high-risk family members at a cytogenetic level in addition to the common clinicopathological traits.

Quantification of additional short arms of chromosome 12 in germ cell tumours using the polymerase chain reaction

Male germ cell tumours are characterised by the over-representation of 12p sequences, most often in the form of isochromosome i(12p). This study describes the development of a quantitative detection system for additional copies of 12p employing the polymerase chain reaction (PCR). The validity of this method was assessed on two i(12p) containing tumour cell lines in which the number of i(12p) was determined by fluorescence in situ hybridisation. Fourteen primary male germ cell tumours were analysed using the PCR-based method. While 3/8 seminomatous germ cell cancers did not contain any additional 12p, all 6 non-seminomatous tumours did and the severity of the disease correlated with the respective copy number. The ease of the PCR-based method makes it possible for the quantification of additional 12p to become a routine diagnostic and prognostic tool for testicular germ cell tumours, thereby helping to define the role of the i(12p) anomality in larger retrospective studies.

Germ cell tumours in a brother and sister

In familial germ cell tumour cases, a normal chromosomal karyotype pattern is rare. We report the findings of germ cell tumours in two siblings with a normal chromosomal karyotype. One of these patients had dysgerminoma in the right ovary and was treated successfully for this. At present, she is 23 years old and has two daughters. The other patient is a 15-year-old boy, who is the brother of the first patient and has mediastinal embryonal carcinoma. Although ultrasonography of the testes showed irregularity in the shape and non-homogeneity of the parenchyma, histopathological examination was found to be normal at the time of diagnosis. At present, he is doing well and his chemotherapy is continuing. Both of them have a normal chromosomal karyotype, 46, XX and 46, XY, respectively. We suggest that children who have a sibling with germ cell tumour should be carefully assessed for development of another germ cell tumour.

Musculoskeletal oncology--advances in cytogenetics and molecular genetics and their clinical implications

Although musculoskeletal malignancies comprise a small group of cancers, a vast number of histological subtypes have been identified attesting to the heterogeneity of this class of tumours and the growing interest in their development. The mode of management for both bone and soft tissue sarcomas has been examined extensively and treatment guidelines have been proposed. Despite the intensive study and multidisciplinary treatment, a substantial proportion of tumours remain recalcitrant to therapy and recur locally and systemically. Improved methods of characterising these tumours may help in understanding their biology. Cytogenetic and molecular genetic techniques allow a subcellular dissection of these malignancies which may aid the identification of mechanisms that are important in tumorigenesis. Already candidate genes have been isolated which may play an important role in the deregulation of proliferation and or the adoption of a malignant phenotype, features which are fundamental in tumour development. By studying the molecular biology and cytogenetics of tumours it may be possible to improve diagnostic and prognostic accuracy thereby minimising over and under treatment.

dic(4;17)(p11;p11): a new recurrent chromosomal abnormality in chronic B-lymphoid disorders

We describe a new nonrandom rearrangement, dic(4;17)(p11;p11), which was identified in three patients with small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). All three cases had in common atypical morphological features with a significant component of prolymphocytes, an unusual clinical outcome, and were refractory to chemotherapy. To further define the cytogenetic breakpoints, we investigated the cases by whole chromosome painting and fluorescence in situ hybridization (FISH) with centromeric probes. FISH analysis detected the same cytogenetic rearrangement in all patients, suggesting that the dic(4;17)(p11;p11) is a recurrent translocation in SLL/CLL. Moreover, FISH analysis showed a monoallelic deletion of the TP53 gene in all cases, suggesting a correlation with the aggressive course of the disease and the clinical outcome observed in these patients.

Cytogenetic analysis of salivary gland type tumors

Fourteen salivary gland type tumors were analyzed with a combination of conventional cytogenetics via GTG-banding, molecular cytogenetics via fluorescent in situ hybridization, and chromosome morphometry. Nine tumors were benign (eight pleomorphic adenomas and one Warthin tumor) five tumors were malignant (one carcinoma ex pleomorphic adenoma, two adenoid cystic carcinomas including one from the breast, a basal cell adenocarcinoma, and an acinic cell carcinoma). Thirteen specimens grew in tissue culture; the basal cell adenocarcinoma did not grow. The Warthin tumor had a normal karyotype, one pleomorphic adenoma was normal, one had a clone with a missing Y chromosome, and the other pleomorphic adenomas had structural chromosomal abnormalities including the following: translocations between chromosomes 3 and 8, chromosomes 6 and 16, chromosomes 8 and 9, chromosomes 8 and 12, chromosomes 8 and 14, and chromosomes 8 and 21. Of the four malignant tumors with karyotypes, the acinic cell carcinoma and one adenoid cystic carcinoma were normal, the second adenoid cystic carcinoma showed a normal polymorphic variant, whereas the carcinoma ex pleomorphic adenoma demonstrated the following karyotype: 46,XX,dir ins(8;5)(q12;q12q35), add(12)(p13)/46,XX. In conclusion, 66% of the benign tumors and 25% of the malignant tumors demonstrated abnormal karyotypes.

Fluorescent in situ hybridization assessment of chromosome 8 copy number in breast cancer

Conventional cytogenetics of breast and other solid tumors has been hampered by a number of factors. An analysis of breast tumor tissues was therefore undertaken using fluorescent in situ hybridization (FISH). A total of 34 specimens were analyzed using a chromosome 8-specific alpha-satellite probe. Various approaches were tested and compared. Among 30 informative samples, 11 infiltrating ductal carcinomas, not otherwise specified (NOS), 5 ductal carcinomas in situ, 5 lobular carcinomas, 3 papillary carcinomas, and 6 benign lesions were studied. Of the 11 cases of infiltrating ductal carcinomas (NOS) analyzed, four cases showed 3 signals, one case showed 4 signals, and the rest showed 2 signals. Of the 5 cases of ductal carcinoma in situ samples, 1 showed 3 signals and the other 4 cases showed 2 signals. All cases of lobular carcinomas, papillary carcinomas, and benign lesions showed 2 signals. We inferred from these data that 36% of the infiltrating ductal carcinomas (NOS) were trisomic and 9% were tetrasomic, whereas 20% of the ductal carcinomas in situ were trisomic. All samples from lobular carcinomas, papillary carcinomas, and the benign lesions were disomic. From our preliminary data, it can further be concluded that a subset of breast cancer is characterized by chromosome 8 trisomy. These data are consistent with an ever-increasing database on the association of chromosomal 8 trisomy with other cancers such as leukemia, lymphoma, prostate cancer, ovarian carcinoma, salivary gland tumor, malignant melanoma, desmoid tumors, and recently gestational trophoblastic disease. It is also noted that the ability to analyze formalin-fixed, paraffin-embedded archival material will enable a more comprehensive cytogenetic study of breast cancer than is currently available.

A fluorescence in situ hybridization (FISH) analysis with centromere-specific DNA probes of chromosomes 3 and 17 in pleomorphic adenomas and adenoid cystic carcinomas

Aberrations of chromosomes 3 and 17 were studied by FISH using centromere-specific DNA probes in 11 salivary adenoid cystic carcinomas (ACC) and 8 salivary pleomorphic adenomas (PA), with 3 lymph nodes as controls. Two hybridized signals were detected in 92.8 +/- 2.7% of controls, 73.2 +/- 7.0% of PA and 66.8 +/- 7.9% of ACC cells for chromosome 3, and in 90.4 +/- 2.3% of controls, 59.5 +/- 25.0% of PA and 44.8 +/- 20.2% of ACC for chromosome 17. More than 3 hybridized signals, which indicate polysomy, were observed in 3.1% of controls, 15.5% of PA and 22.9% of ACC cells for chromosome 3, and in 1.2% of controls, 10.3% of PA and 23.1% of ACC cells for chromosome 17. A single hybridized signal was much more frequent for chromosome 17 than for chromosome 3. These findings suggest that polysomy of both chromosomes occurs during the development of salivary gland tumors, and its frequency is increased in adenoid cystic carcinoma as compared to pleomorphic adenoma. In addition, monosomy of chromosome 17 could possibly be significant in salivary gland tumors.

Recent developments in soft tissue tumors

This article reviews the clinicopathological features of several recently described soft tissue tumours, namely ossifying fibromyxoid tumour, angiomyofibroblastoma, epithelioid angiosarcoma, retiform haemangioendothelioma, intra-abdominal desmoplastic small cell tumour, spindle cell liposarcoma and low grade fibromyxoid sarcoma. Conceptual changes are also discussed. These include the relationship between Ewing's sarcoma and peripheral primitive neuroectodermal tumour, the proposed use of the term atypical lipoma for a subset of well differentiated liposarcomas, and the occurrence at a wide variety of sites of inflammatory myofibroblastic lesions of uncertain biological potential. In addition, advances in the study of soft tissue lesions at the molecular and cytogenetic levels are outlined, with particular emphasis on the recent identification of tumour-specific karyotypic abnormalities in a wide variety of sarcomas.

Monoclonal gammopathy of undetermined significance: chromosome changes are a common finding within bone marrow plasma cells

We used two indirect approaches [image analysis (Feulgen staining) and fluorescence in situ hybridization (FISH)] to study bone marrow plasma cells (BMPC) in 28 patients fulfilling criteria for MGUS. 61% of patients were found to be aneuploid after image analysis: three were hypodiploid and 14 were hyperdiploid. 12/14 hyperdiploid patients also revealed abnormalities after FISH: 12-72% of BMPC exhibited trisomy for at least one of chromosomes 3, 7, 9 and 11. These latter chromosomes are the four chromosomes most frequently implicated (in the shape of trisomy) in MM, confirming the tight relationship between both conditions. After a median follow-up of 19 months (12-41 months) no patient developed overt MM. Also, we failed to find any relationship between currently available biological parameters and DNA findings. As literature data give a transformation rate of 20-30% after a follow-up of 20-35 years, it is worth presuming that some aneuploid patients will evolve to MM, whereas others (also with aneuploid bone marrow plasma cells) will never develop cancer. Our findings indicate that numeric abnormalities, as they are shared both by MGUS and MM patients, are certainly an additional or a prerequisite event, but are not related to an overt disease. They also emphasize the importance of cytogenetic study in the pathophysiology of MGUS.

Solid alveolar rhabdomyosarcoma with a t(2;13)

We report a child with a progressive "solid alveolar rhabdomyosarcoma" in whom analysis of tumor cells revealed a t(2;13) translocation characteristic of the classical alveolar subtype. Both subtypes of alveolar rhabdomyosarcoma are associated with a poor response to treatment and the occurrence of this translocation in both is suggestive of a common biologic origin.

Characteristic chromosome abnormalities and karyotype profiles in soft tissue tumors

Characteristic chromosome abnormalities and karyotype profiles are emerging for the soft tissue tumors. The notable findings are summarized in the Table 1. Within the broad range of solid tumors, it is certainly the soft tissue tumors in which the most spectacular success has occurred with regard to neoplasia-associated chromosome abnormalities. Cytogenetic studies of soft tissue tumors have been encouraged by the early and growing supporting interest of pathologists and clinicians concerned with soft tissue tumors. However, when one considers the variety of types and subtypes of benign and malignant soft tissue tumors, the number that has been so far characterized by a specific chromosome change is still very small. But, as we attempt to demonstrate in this report, these data should be viewed as paradigms for the importance of cytogenetic investigations in solid tumors. Cytogenetic studies of solid tumors are of more than clinical interest. Cytogenetic studies allow molecular investigations of the chromosomal breakpoints. They allow the search to proceed for genes involved in the chromosomal changes, providing a better knowledge of the malignant transformation process. In addition, the fruits of the combined efforts in cytogenetic and molecular technologies, from which has come "molecular cytogenetics," will let us recognize more conveniently, more quickly and, hopefully, less expensively the well-characterized diagnostic chromosome markers in tumor cells. Thus, we may be able to reach the goal of incorporating cytogenetics into standard diagnostic procedures for solid tumors, as has been achieved with hematological malignancies. Molecular cytogenetics including fluorescent in situ hybridization (FISH) technology promises to bring soft tissue tumor cytogenetics into regular diagnostic armamentaria and concurrently speed research into the basis of soft tissue tumors.

Chromosome analysis of brain tumors in childhood

We performed a chromosome analysis of 26 pediatric brain tumors, including 20 primitive neuroectodermal tumors (PNETs). 5 astrocytomas, and 1 immature teratoma. Specimens were treated with collagenase, placed in overnight or short-term cultures, and harvested for chromosome analysis. Numerical and/or structural abnormalities were noted in 14 of the 20 PNETs and 4 of the 5 astrocytomas. In 13 PNETs, so-called medulloblastoma in the cerebellum, an i(17q) was the most frequent structural abnormality, accounting for 30% (4/13). Double minute chromosomes (dmin) were observed in one tumor. Near-diploidy was demonstrated in three of these PNETs, hyperdiploidy in three, and near-tetraploidy in three. We could not find any correlation of these cytogenetic findings with the prognosis. In the remaining seven PNETs other than medulloblastoma, the karyotypes of five PNETs demonstrated a variety of numerical and structural abnormalities. As to the astrocytomas, losses of chromosomes 7 and 9 with dmin were observed in two, and structural abnormalities of chromosomes 1 and 17 were also observed in two tumors. In our limited cases, however, we could not find the same chromosome abnormalities that are well known in adult astrocytomas. A congenital immature teratoma showed hyperdiploidy with increased numbers of chromosomes 3, 6, and 12. We conclude that i(17q) is an important chromosome abnormality in medulloblastomas, and that the oncogenesis of pediatric astrocytomas might be different cytogenetically from that of adult astrocytomas.

Trisomy 5 as the sole chromosomal abnormality in a primary mucoepidermoid carcinoma of the minor salivary gland

We describe the cytogenetic findings in a moderately differentiated primary mucoepidermoid carcinoma of the base of the tongue. The only karyotypic abnormality found in the primary culture of this neoplasm was trisomy 5. This finding is remarkably different from previous cytogenetic studies of mucoepidermoid carcinomas, which have shown heterogeneous and unrelated chromosomal aberrations. Our results suggest that trisomy 5 may be an early aberration in the development of this neoplasm.

Numerical chromosomal aberrations in thyroid tumors detected by double fluorescence in situ hybridization

Double fluorescence in situ hybridization with DNA probes specific for the (peri)centromeric regions of chromosomes 3, 7, 9, 11, 12, 18, and X was performed on fresh isolated nuclei and frozen tissue sections prepared from 2 nodular hyperplasias, 2 adenomas, and 7 papillary carcinomas of the thyroid in order to detect numerical chromosomal changes. Numerical chromosomal aberrations were found in all malignant specimens examined. A consistent presence of at least two trisomies was detected in most cases, especially in the follicular variant specimens; the highest degree of trisomy was observed for chromosome 12. Isolated monosomies of moderate degree for different chromosomes were found in 1 adenoma and 2 papillary carcinomas. Severe monosomy of chromosome 9 was the only significant feature observed in the single metastatic papillary carcinoma.

Clinical follow-up in 24 nonfamilial renal tumors cytogenetically characterized in tissue culture

OBJECTIVE

This study investigates the relationship between clonal chromosomal abnormalities detected in nonfamilial renal cell carcinoma and the clinical outcome, specifically, whether or not patients whose tumors had karyotypic changes have a different prognosis than those whose tumors did not.

METHOD

Fresh tumor tissue obtained from 32 cases was grown in tissue culture. Twenty four grew successfully and were harvested and multiple cells of each karyotyped. Clinical follow-up was obtained for at least five years or until the time of death.

RESULTS

Fourteen of 24 cases demonstrated karyotypic abnormalities including loss of Y chromosome (64%), trisomy 7 (50%), trisomy 12 (14%), trisomy 9, 10, 14, 15, 16, and 17, monosomy 9 and 20, and long-arm deletion of chromosome 16 (1 case each). Tumors were well-differentiated in 16 cases, moderately differentiated in 5 cases, and poorly differentiated in 1 case; 13 cases were pathologic Stage I, 5 Stage II, and 6 Stage III. Thirty-three percent of the patients demonstrated clinical progression.

CONCLUSIONS

No significant difference in prognosis could be found between patients with and without karyotypic abnormalities. The only clinical or pathologic difference which could be established was sex distribution. Significantly greater numbers of males had karyotypic abnormalities than females, but this could be explained by the high number of Y chromosome deletions that were detected. The lack of correlation between karyotypic abnormalities and clinical outcome may reflect a confounding factor in genetic evolution such that clinically determining chromosomal changes present early in a tumor's growth in vivo may no longer be present when the tumor is diagnosed, treated, or after it is grown in culture. This may make demonstration of such clinically significant chromosomal changes very difficult.

Cytogenetic findings in pituitary adenoma: results of a pilot study

Pituitary adenomas are the most common tumors of the sellar region and are, with rare exception, benign neoplasms. The natural history of these lesions is only poorly understood and, although histologic, immunocytologic, and ultrastructural characteristics have been well established, predicting the natural history of individual tumors is, at best, unreliable. In an effort to better characterize pituitary adenomas, we have analyzed the karyotypes of 18 surgical specimens and attempted to correlate with the morphologic appearance and the clinical data, for example, endocrinologic subtypes, histology, and tumor invasiveness. Most hormonal subtypes were studied including seven growth hormone-prolactin (GH-PRL), two Prolactin (PRL), two Adrenocorticotrophin (ACTH), seven nonsecretory (NULL). No correlations with morphology or invasiveness could be made. Of 7 null cell adenomas, five (71%) had normal karyotypes, whereas of 11 hormone-secreting adenomas three (28%) were normal. Of seven tumors with mixed GH-PRL activity, six had abnormal karyotypes. At least three chromosomes harbored abnormalities shared by more than two tumors. The results demonstrate that chromosome abnormalities are also found in benign tumors. These findings, however, suggest that hormone-secreting adenomas may be more likely to be associated with karyotypic abnormalities especially those of the GH-PRL variety. Genetic abnormalities associated with chromosomes 1, 4, 7, and 19 were common and warrant further investigation.

Polymerase chain reaction-based restriction fragment length polymorphism analysis of the short arm of chromosome 3 in primary head and neck squamous carcinoma

BACKGROUND

Deletion or loss of heterozygosity (LOH) at the polymorphic loci on the short arm of chromosome 3 has been reported in a large number of renal cell, small cell lung, non-small cell lung, and cervical carcinomas, suggesting the presence of one or more putative tumor suppressor genes at chromosome 3p. Similar studies in primary head and neck carcinoma are lacking.

METHODS

To investigate the possibility of chromosome 3p deletions, the authors applied a polymerase chain reaction (PCR)-based, restriction fragment length polymorphism analysis, in conjunction with conventional Southern blot techniques, to DNA samples of matched normal mucosa and head and neck squamous cell carcinomas from 18 patients. The authors also assessed the merit of the PCR-based assay as a rapid screening tool, particularly in assaying limited tissue samples.

RESULTS

Constitutional heterozygosity at the polymorphic loci varied in the 18 normal samples that the authors studied: 12 at the D3F15S2 locus (on telomeric 3p21), 7 at the D3S32 locus (on centromeric 3p21), and 9 at the THRB locus (on 3p24). In 18 matched carcinoma specimens, LOH (deletion) was observed at D3S32 in 0 of 7, at D3F15S2 in 9 of 12 (75%), and at THRB in 3 of 9 cases (33%).

CONCLUSIONS

The results of the PCR-based assay and Southern blotting were completely concordant in all specimens the authors studied. This study indicates that deletion at 3p is a frequent abnormality in primary head and neck carcinoma and that the most common deletion region is telomeric to D3S32. The authors also observed an apparent correlation among poor histologic differentiation, DNA aneuploidy, and 3p deletions. Most poorly and moderately differentiated and aneuploid carcinomas manifested the 3p deletion. Therefore, the authors suggest an association between deletion at 3p and aggressive biologic behavior.

Cytogenetic findings in 18 follicular thyroid adenomas

Cytogenetic study of 18 follicular thyroid adenomas showed clonal chromosome changes in 12 tumors. These results suggest the existence of at least three cytogenetically distinct subgroups: a hyperploid group characterized by the presence of a cluster of numerical changes including +5, +7, and +12 as the most frequent anomalies and, less frequently, +4, +9, +14, +16, and +17; a pseudo- or near-diploid group characterized by simple karyotypic aberrations; and a cytogenetically normal group.

Chromosome analysis of adenomatous polyps of the colon: possible existence of two differently evolving cytogenetic groups

A chromosomal study of 42 colonic adenomatous polyps was performed using a technique of direct chromosome analysis derived from the prenatal procedure for diagnosing chromosomal alterations from chorionic villi sampling. Abnormal karyotypes were found in 22 cases. Trisomy 7, the most frequently found alteration, was found in 13 cases, followed by trisomy 13 (nine cases). Monosomy 18 was observed in two cases; in one of these, that of a polyp which had degenerated into an intra-mucosal adenocarcinoma, it was associated with 17p monosomy. Interestingly, these two types of alterations (trisomy 7 versus 18 and 17p monosomy) were not found together in the same lesion. This suggests that there could be two distinct chromosomal behaviors which might be related to the two cytogenetic groups described for colorectal adenocarcinoma. However, the respective frequencies of such cytogenetic groups varied inversely between adenomas and adenocarcinomas, thus suggesting that they evolve differently.

Multiple polyps of esophagus, stomach, colon, and rectum accompanying rectal cancer in a patient with constitutional chromosomal inversion

BACKGROUND

It has been reported that colorectal carcinomas are caused by a multistage process. In patients with familial adenomatous polyposis, carcinoma of the colorectum frequently develops and occasionally polyps develop in the upper gastrointestinal tract. Chromosomal deletion often is found for chromosomes 5, 17, and 18, on which tumor suppressor genes are located. Furthermore, loss of the alleles of loci on chromosome 3 has been reported in renal cell carcinoma, small cell lung carcinoma, and mixed salivary gland tumor in hereditary and sporadic cases. These data support the concept of a recessive mechanism for the development of human tumors.

PATIENTS AND RESULTS

The authors report the case of a 48-year-old woman with rectal cancer accompanied by multiple polyps in the esophagus, stomach, and colorectum. Histologically, the polypoid lesions in the esophagus, stomach, and colorectum showed a thickened mucosa, hyperplastic polyps, and mixed hyperplastic adenomatous polyps, respectively. Karyotype analysis showed 46, xx, inv(3)(p12.2q25.3) in all 20 inspected peripheral lymphocytes. By Southern blot with a c-raf probe, one allele of the c-raf-1 gene, which has been mapped on chromosome 3p25, was deleted from the rearranged chromosome 3 in the peripheral lymphocytes, intact colonic mucosa, and cancer tissue.

CONCLUSIONS

These results suggest that the development of hyperplastic polyps and carcinoma of the rectum results from the allelic loss in chromosome 3p, as has been reported for solid tumors at other sites.

Malignant germ cell tumours in two siblings

Familial germ cell tumours are well recognised in kinship with gonadal dysgenesis, but their occurrence in siblings with normal chromosomes is rare. We report two sisters who presented within a 4 month period with malignant ovarian germ cell tumours; one a dysgerminoma and the other a mixed tumour with marked choriocarcinomatous elements. Both children had a normal female constitutional karyotype and normal phenotype.

Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study

Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective chromosomal modes. However, no correspondence between chromosomal modes and mean nuclear area was found. Chromosomal markers have been identified that particularly affect chromosomes 1 (p11, q21-qter), 11 and 16, although no common markers existed in all cases. Cytogenetics is the most sensitive technique, but the low yield (22 out of 140 tumors assayed) considerably restricts its value in any prospective breast cancer study.

t(13q;17p) and del(5q): possibly specific changes in Chinese patients with colorectal cancers

Cytogenetic study of 18 colorectal carcinomas confirmed the extensive heterogeneity and the complexity of the karyotypic picture in this type of tumor. Karyotypic analysis showed that chromosomes 17p and 5q, in both numerical and structural aspects, were the most frequently involved chromosomes and prone to losses. The most common structurally rearranged forms were translocations of 17p with other chromosomes, especially t(13q;17p), which constituted over 50% of all 17p rearrangements, and an interstitial deletion of 5q that made up as much as 73% of all structural abnormalities of 5q. According to the results, we conclude that chromosomes 17 and 5 may play important roles in the evolution of colorectal cancer and t(13q;17p) and del(5q) may be possibly specific to Chinese patients with colorectal cancer.

Cytogenetic analysis of an adenoid cystic carcinoma of the Bartholin's gland. A rare, semimalignant tumor of the female genitourinary tract

Cytogenetic analysis has been performed on short-term cultures from a 56-year-old woman suffering from an adenoid cystic carcinoma of Bartholin's gland. Beside a normal female karyotype, the tumor revealed an abnormal cell line with complex chromosome changes involving the chromosomes 1, 4, 6, 11, 22, and 14. The mainly structural and nonbalanced rearrangements led to the loss of the chromosome segments 1p31----qter, 4q22----q28, 6p12----qter, 11p11.2----pter, 14q24----qter, and 22q13----qter. Clonal numerical aberrations were not observed. To our knowledge, such a tumor has to-date not been cytogenetically investigated.

Chromosome studies of solid tumours

Images

Translocation t(5;19): a recurrent change in thyroid follicular adenoma

The cytogenetic study of a follicular thyroid adenoma revealed a t(5;19)(q13;q13.3). This is the second report of a translocation between chromosomes 5 and 19 in a thyroid follicular adenoma.