[Specific chromosome aberrations in human soft-tissue tumors and their diagnostic significance]. / Swoiste aberracje chromosomowe w nowotworach tkanek miekkich i ich znaczenie diagnostyczne.

Recent cytogenetic studies have revealed that several types of benign and malignant human soft tissue tumors are characterized by highly specific chromosome abnormalities. In this article, we review the primary and secondary chromosome aberrations detected in lipoma, uterine leiomyoma, Ewing sarcoma, rhabdomyosarcoma, myxoid liposarcoma, synovial sarcoma, and clear cell sarcoma of tendons and aponeuroses. The primary aberrations are unique for the particular tumor type and therefore are of diagnostic value. Most recent molecular studies indicate that several sarcoma-specific translocations result in the gene fusion and creation of tumor-specific proteins that are novel DNA transcription factors.

Cytogenetic and immunohistochemical profile of myxoid liposarcoma.

Cytogenetic and immunohistochemical studies were performed in nine myxoid liposarcomas. The tumor karyotype was determined after short-term culture of cells in vitro. Immunohistochemical studies were performed on frozen tissue in five cases and on paraffin-embedded tissue in three cases. Chromosomal analysis demonstrated a balanced translocation t(12;16) (q13;p11) as the sole abnormality in four cases. Two cases showed an association with other abnormalities. Three tumors showed variants of the t(12;16) translocation involving other chromosomes. In all cases studied, the 12q13 breakpoint was involved in rearrangements. In the majority of cases, immunohistochemical studies demonstrated vimentin (9 of 9) and S-100 protein (8 of 9). Strong focal expression of desmin was observed in two tumors. Weak focal expression was observed in three tumors. Two tumors, which were both desmin positive, showed focal expression of MSA and alpha-SMA. Strong expression of CD36 was present in all four cases that were studied for this marker. CD34 was negative in tumor cells, but it highlighted an intricate capillary network in the tumor. Close relationship between the tumor cells and pericapillary pericytes was demonstrated with CD34 and alpha-SMA strains. The authors conclude that myxoid liposarcoma is characterized by a specific chromosomal rearrangement. Its immunohistochemical profile is wider than previously believed, including expression of muscle markers.

Non-isotopic procedure with silver staining of polyacrylamide gels in detection of genomic abnormalities in tumors using microsatellites.

Microsatellite-based PCR (polymerase chain reaction) with silver staining of polyacrylamide gels as an alternative approach to detect genomic abnormalities in tumors has been developed. In experiments with a series of primers for microsatellite sequences located on human chromosome 5 we found that a 2- to 4-fold increase or decrease in the ratio of amount of allelic microsatellite sequences can be reliably assessed from the relative intensity of corresponding PCR products. Results of the studies of renal carcinoma cell lines carrying increased or decreased numbers of specific allelic markers on chromosome 5 assessed by cytogenetics, Southern blotting-restriction fragment length polymorphism and microsatellite analyses were consistent. Microsatellite studies performed on samples obtained from formalin-fixed paraffin-embedded archival material allowed detection of genomic abnormalities of chromosome 5 in five of ten primary renal cell carcinomas.

Nonrandom secondary chromosome-aberrations in synovial sarcomas with t(x-18).

Thirty samples from 19 patients with synovial sarcoma were analyzed cytogenetically after short-term culturing. Thirteen samples were from primary tumors, 11 from local recurrences, and six from distant metastases. All samples showed the characteristic aberration t(X;18)(p11;q11) or variants thereof; 23 samples had additional numerical and/or structural changes. Including the present cases, chromosome aberrations have been reported in 74 synovial sarcomas, 50 of which have had secondary aberrations in addition to t(X;18). No secondary structural aberration was recurrent. The most common numerical changes were +7, +8, +12 (10 cases each), -3, +9, +21 (7 cases each), +2, -14, -17 (6 cases each), +4, -11, +15, and -22 (5 cases each). Unbalanced stuctural aberrations led to loss of 3p and 17p in six cases, each with loss of bands 3p21 and 17p13, respectively, in common. Most monosomies and trisomies seemed to occur at similar frequencies in primary, recurrent, and metastatic tumors. The only exceptions were +2, which was never seen in a primary tumor, and +8, which was never found in any metastatic lesion.

Deletion of chromosome arm 1p in a Merkel cell carcinoma (MCC).

A case of neuroendocrine skin carcinoma (Merkel cell carcinoma) with a deletion of the short arm of chromosome 1 (1p) as the sole chromosomal abnormality was examined. The tumor originated in the skin of the left knee of a 67-year-old man. Histopathologic study showed an undifferentiated small cell tumor which expressed neuron-specific enolase, chromogranin, and cytokeratin (CAM 5.2). Cytogenetic analysis of a lymph node metastasis from the groin showed a pseudodiploid cell population with a deletion of the short arm of chromosome 1 as the only abnormality: 46,XY,del(1)(p36.1). In situ hybridization with the D1Z2 probe specific for the terminal band of 1p confirmed the terminal deletion. This is the first case of Merkel cell carcinoma in which only one chromosomal abnormality has been observed. Loss of the terminal portion of 1p suggests that a tumor suppressor gene on 1p plays a role in the pathogenesis of Merkel cell carcinoma.

Cytogenetic analysis of an immature teratoma of the ovary and its metastasis after chemotherapy-induced maturation.

We report a case of an immature teratoma of the ovary, grade 3, in which cytogenetic studies were performed on the primary tumor at diagnosis and on a metastasis resected 1 year after removal of the primary tumor. The patient was treated with cisplatin, bleomycin, and etoposide (VP-16) combination chemotherapy. The metastatic tumor was composed of mature teratoma with only small foci of immature tissue. Despite the different histologic appearance of the primary tumor and the metastasis, there was no detectable difference in karyotype between the primary and metastatic tumors. Both showed a pseudodicentric chromosome derived from chromosome 1 and monosomy for chromosome 4. Flow cytometry analysis of the metastatic tumor showed a diploid DNA content, in agreement with the cytogenetic findings. From this case it would appear that chemotherapy-induced maturation of metastatic immature ovarian teratoma is not associated with regression of the malignant karyotype or selection of a karyotypically distinct population of tumor cells.

Chromosome errors as a cause of spontaneous abortion: the relative importance of maternal age and obstetric history.

OBJECTIVE: To evaluate the likelihood of obtaining a chromosome diagnosis in cases of spontaneous abortion (SAB) and of the relative importance of maternal age versus obstetric history in predicting the fetal karyotype. DESIGN: Obstetric history was obtained from all 100 cases of miscarriage in 1 year when products of conception were sent for chromosome studies. Multiple logistic regression analysis was used to calculate odds ratio and statistical significance for correlations between historical factors and the probability of any chromosomal abnormality or trisomy. RESULTS: A chromosome diagnosis was made in 84% of cases. Maternal age was a more important predictor of chromosome abnormality, specifically trisomy, than history of previous livebirths or miscarriages. CONCLUSION: Results from chromosome studies using chorionic villi from SABs are diagnostically useful, even when the patient has a history of repeated miscarriages.

Analysis of chromosome aneuploidy in ovarian dysgerminoma by flow cytometry and fluorescence in situ hybridization.

We determined the DNA ploidy and the centromeric copy number of chromosomes 7, 12, 18, and X in four cases of ovarian dysgerminoma using DNA flow cytometry and fluorescence in situ hybridization (FISH) with chromosome-specific alpha-satellite probes. The analyses were performed on nuclei isolated from paraffin-embedded tissue. The DNA index of the tumors ranged from 1.75 to 2.08 (near tetraploid). The FISH analysis demonstrated five copies of chromosome 7 and four copies of chromosome 12 in most tumors. The copy number of chromosome 18 ranged from two to four. The X chromosome was present in three copies in most tumors. These data show that the aneuploidy profile of dysgerminoma is similar to that of testicular seminoma. Overrepresentation of chromosomes 7 and 12 and under-representation of chromosome 18 are characteristic cytogenetic features of seminoma. Seminoma and dysgerminoma share the same chromosomal marker, an isochromosome i(12p). Our data suggest that these tumors are also characterized by a similar, nonrandom pattern of chromosome gains and losses.

Retinoic acid-induced differentiation of the developmentally pluripotent human germ cell tumor-derived cell line, NCCIT.

BACKGROUND: Germ cell tumors are empirically divided into seminomas and nonseminomatous germ cell tumors (NSGCT). Some authorities consider seminomas to be the precursors of NSGCT, whereas others consider them as distinct and unrelated neoplasms. Here, we report that the human NSGCT-derived stem cell line, NCCIT has hybrid features of seminoma and embryonal carcinoma, and suggest that this cell line could be useful for studying the relationship of seminoma to NSGCT. EXPERIMENTAL DESIGN: NCCIT, a developmentally pluripotent permanent cell line derived from a mediastinal NSGCT was karyotyped and characterized morphologically, immunochemically, and biochemically. The cells were grown under standard tissue culture conditions and were also exposed to retinoic acid to induce differentiation. RESULTS: The dividing NCCIT stem cell populations consist of vimentin-positive, keratin-negative cells that do not express desmoplakin or cadherin E (uvomorulin) and are not interconnected with one another. These cells have a high nucleocytoplasmic ratio and contain few cytoplasmic organelles, except for free ribosomes and a small number of mitochondria. Lacto- and globoseries oligosaccharide antigens recognized with antibodies to murine stage specific antigens 1, 3 and 4 (SSEA-1, SSEA-3 and SSEA-4), and human teratocarcinoma mucin-like antigen TRA-1-60 and TRA-1-81 are coexpressed on the cell membranes of a considerable number of stem cells. On most cells alkaline phosphatase can be detected by enzyme histochemistry. The placental isoenzyme of alkaline phosphatase was demonstrated by Western blotting in cell extracts. The liver/bone/kidney isoenzyme of alkaline phosphatase is immunochemically detected on 40% of cells. The culture supernatants also contain chorionic gonadotropin and alpha-fetoprotein, presumably derived from trophoblastic and yolk sac-like cells. The cells are hyperdiploid (chromosome range from 54 to 64) and show prominent structural chromosomal aberrations, mostly deletions and isochromosomes. Retinoic acid treatment inhibited the growth of NCCIT cells and induced stem cell differentiation into keratin, glial fibrillary acid protein, and neurofilament-positive somatic cells. The differentiation was associated with the disappearance of oligosaccharide surface antigens typical of the undifferentiated stem cells; a loss of proteins typical of undifferentiated cells and the appearance of new proteins; and the deposition of extracellular matrix. CONCLUSIONS: NCCIT is a developmentally pluripotent cell line that can differentiate into derivatives of all three embryonic germ layers (i.e., ectoderm, mesoderm, and endoderm) and extraembryonic cell lineages. We suggest that this cell line could be a malignant replica of human cleavage stage embryonic cells with features intermediate between seminoma and embryonal carcinoma.

Cytogenetic study of botryoid rhabdomyosarcoma of the uterine cervix.

We report a case of sarcoma botryoides of the uterine cervix occurring in a 19-year-old woman. By light microscopy the tumor showed round and spindle cells with hyperchromatic nuclei and, focally, a cambium layer subjacent to the surface epithelium and surrounding endocervical glands. Strap-shaped cells with and without cross-striations and small foci of immature cartilage were also present. Immunohistochemical studies showed positive staining within the tumor cells for myoglobin, desmin, vimentin, muscle-specific actin and CD56. By electron microscopy, tumor cells showed cytoplasmic filaments in an alternating pattern of thick and thin filaments. Chromosomal analysis demonstrated deletion of the short arm of chromosome 1, and trisomies 13 and 18. To our knowledge, this is the first reported case of sarcoma botryoides of the endocervix with chromosomal analysis.

Recurrent parapharyngeal rhabdomyoma. Evidence of neoplastic nature of the tumor from cytogenetic study.

A 64-year-old Caucasian male with a left parapharyngeal mass had a past medical history that was significant for excision of a benign rhabdomyoma of the soft palate 30 years previously. Then 25 years ago, the tumor recurred in the palate and retropharyngeal space on the left and was reexcised. Histologic examination of all three excisions showed adult rhabdomyoma. Ultrastructural and histochemical studies of the second excision of this tumor have been published previously. The present study included histologic, ultrastructural, immunohistochemical, and cytogenetic analyses. The histologic and ultrastructural features of the tumor were identical to those reported 25 years ago. Immunohistochemical studies demonstrated that the tumor cells were desmin and myoglobin positive and vimentin negative. Focal positivity for CD56 was also present. Intracellular inclusions in the tumor cells were strongly positive for desmin. Cytogenetic examination of short-term cultures of the tumor cells demonstrated clonal chromosome abnormalities in 60% of metaphases. The majority of cells showed a reciprocal translocation between chromosomes 15 and 17 as the sole abnormality. A minor clone was characterized by abnormalities of the long arm of chromosome 10. The presence of clonal structural chromosome abnormalities in extracardiac adult rhabdomyoma lends strong support to the idea that these rare tumors are true neoplasms rather than hamartomatous or regenerative lesions.

Dissecting aortic aneurysm as a complication of generalized fibromuscular dysplasia.

This is the first report of a dissecting aneurysm of the aorta caused by generalized vascular fibromuscular dysplasia. An 18-year-old black man suddenly developed paraparesis and bilateral pulse loss below the waist. An aortogram disclosed a dissecting aneurysm of the entire aorta and an obstruction of blood flow below the renal arteries. On postmortem examination, the dissection of the aorta was found to be due to fibromuscular dysplasia that affected not only the aorta, but multiple other arteries as well.

Chromosomal abnormalities in two chordomas.

Cytogenetic analyses of two sacral chordomas are reported. Both tumors showed clonal chromosome abnormalities, including numerical and structural aberrations. The modal chromosome numbers were 36 and 72, respectively. The hypodiploid tumor had a single structural abnormality identified as a der(21)t(1;21)(q21;q22). The near-triploid tumor had numerous structural rearrangements, including a der(21)t(2;21)(q11;q22), which involves the same band of chromosome 21 as the translocation in the first tumor. Prophasing was a prominent cytogenetic feature of this tumor. The consistent involvement of band 21q22 in translocations in two chordomas suggests a possible specific association of this chromosome region with chordoma. Protooncogenes ETS2 and ERG have been mapped to this chromosome band.

Placental mosaicism in a case of 46,XY,-22,+t(22;22)(p11;q11) or i(22q) diagnosed at amniocentesis.

46,XY,-22,+t(22;22)(p11;q11) or i(22q) was diagnosed in 15/15 cells from two cultures from the amniotic fluid culture of a 31-year-old patient whose fetus demonstrated cystic hygroma on ultrasound. Cytogenetic studies performed on fetal skin from the abortus revealed the same karyotype as that seen on amniocentesis, but the placenta demonstrated a 46,XY/46,XY,-22,+t(22;22) or i(22q) mosaicism, with 65 per cent of the cells being 46,XY. This case provides an example of placental mosaicism for a normal male karyotype, while the fetus demonstrated non-mosaic trisomy 22.

Ovarian granulosa-stromal cell tumors are characterized by trisomy 12.

Eleven ovarian granulosa-stromal cell tumors including 1 thecoma, 2 fibromas, 6 fibrothecomas, and 2 granulosa cell tumors, were karyotyped after direct harvest and/or short-term tissue culture. Bilateral fibrothecomas from one patient appeared to lack cytogenetic aberrations: the remaining nine tumors were characterized by trisomy for chromosome 12. Cytogenetic aberrations in the two granulosa cell tumors were much less complex than those described previously in undifferentiated carcinomas; accordingly cytogenetic analyses might be useful in distinguishing these categories. The consistent occurrence of trisomy 12 in different varieties of granulosa-stromal cell tumors suggests a common mechanism of oncogenesis within this diverse group of neoplasms. That mechanism probably involves promotion of low-grade, orderly cell proliferation.

Two mosaic cases with nonfluorescent Y chromosome analysed with Y-specific DNA probes.

Two cases of a nonfluorescent Y (Ynf) chromosome were diagnosed: one in a male, the other in a female. Both had similar complex mosaic chromosome constitutions with a 45,X cell line. DNA studies were applied in both cases for verification of the cytogenetic diagnosis. The results on the two patients were compared with data obtained from seven healthy men (46,XY), three healthy women (46,XX), two females with 46,XY karyotype, and from cell lines with 49,XXXXY and 48,XXXX chromosome constitution. The highly repetitive Y-specific DNA sequences located in the heterochromatic region of the long arm were absent in these patients. Differences in the composition of the euchromatic part of the Y chromosome were demonstrable in both patients. The highly repetitive Y-specific DNA sequences located in the heterochromatic region of the long arm were absent in these patients. Differences in the composition of the euchromatic part of the Y chromosome were demonstrable in both patients. The suggestion that the Ynf chromosome originates from a dicentric Y chromosome cannot be accepted as a complete explanation of the phenomenon, as it probably involves more complex molecular alterations of the abnormal Y chromosome. The presence of Ynf is associated with the presence of a 45,X cell line more often than in cases of simple Y chromosome deletions with the breakpoint localized in or below the Y euchromatin/heterochromatin junction.

Translocation (X;19) with involvement of the inactive X chromosome in oligoblastic granulocytic leukemia.

A 72-year-old female with metastatic breast cancer developed oligoblastic granulocytic leukemia 6 months after initiation of chemotherapy. Cytogenetic examination of the bone marrow cells revealed a balanced t(X;19)(q12;q13.3) as the sole abnormality in 50% of the metaphases. The remaining cells showed a normal female karyotype. The der(19) chromosome displayed consistent folding in the Xq13-q23 region in all metaphases, indicating involvement of the inactive X chromosome in translocation.

Clonal chromosome rearrangements in a uterine myoma.

A cytogenetic study of a myoma of uterus with extensive hyaline, myxoid, and cystic degeneration revealed a clonal karyotype with a complex structural rearrangement involving chromosomes #3, #12, #14, #17, and #22. The modal chromosome number of the tumor was 45 due to monosomy #22. Analysis of seven additional myomas of the uterus including five tumors with typical histology and two with degenerative changes showed no clonal abnormalities. Single metaphases with a trisomy and a translocation were detected in two tumors. We conclude that although many uterine myomas appear to have normal karyotypes, clonal chromosome abnormalities are present in some of these tumors.