Association of trisomy 8 and squamous differentiation in an endometrial adenocarcinoma

Genomic aberrations in carcinomas of the uterine corpus

Endometrial carcinoma, the most common invasive neoplasm of the female genital tract, occurs either in a hormone-related, less virulent form (type I) or in a hormone-independent, more aggressive form (type II). Another cancer of the uterine corpus is carcinosarcoma, a biphasic or mixed epithelial-mesenchymal tumor, now classified as metaplastic carcinoma. We examined by karyotyping and comparative genomic hybridization a consecutive series of 67 endometrial carcinomas and 15 carcinosarcomas and compared the cytogenetic features of the different carcinoma subtypes. All three subtypes of uterine carcinoma had in common a nonrandom gain of material from 1q and 8q but differed from one another in other respects. Endometrial carcinomas of type I mostly presented gains from chromosome arms 1q and 8q and losses from Xp, 9p, 9q, 17p, 19p, and 19q, whereas endometrial carcinomas of type II showed a more complex imbalance picture, with gains from chromosome arms 1q, 2p, 3q, 5p, 6p, 7p, 8q, 10q, and 20q and losses from Xq, 5q, and 17p. The carcinosarcomas mostly showed gains of or from 1q, 5p, 8q, and 12q but losses from 9q, that is, they were much more similar to endometrial carcinomas in their pattern of acquired genomic changes than to sarcomas of the uterine corpus. It was also possible to identify different copy number changes among the different grades of type I carcinomas, between serous papillary and clear-cell carcinomas of type II, as well as between homologous and heterologous carcinosarcomas. Specifically, type I adenocarcinomas that were highly differentiated mostly showed gains from 1q and 10p; those that were moderately differentiated showed gains from 1q, 7p, 7q, and 10q as well as losses from Xp, 9p, 9q, 17p, 19p, and 19q; whereas those poorly differentiated showed gains from 1q, 2p, 2q, 3q, 6p, 8q, and 20q but losses from Xp, Xq, 5q, 9p, 9q, 17p, and 17q. The serous papillary carcinomas showed gains from 1q, 2p, 2q, 3q, 5p, 6p, 6q, 7p, 8q, 18q, 20p, and 20q but losses from 17p, whereas the clear-cell carcinomas showed gains from 3q, 7p, 8q, 10q, 16p, and 20q but losses from 6q. Finally, the homologous carcinosarcomas presented gains from 1p, 1q, 8q, 12q, and 17q as well as losses from 9q and 13q, whereas the heterologous tumors showed gains from 1q, 8p, and 8q. The reproducibility of the observed correlations between karyotypic aberration patterns and histological differentiation was underscored by the fact that those carcinosarcomas whose epithelial component resembled type I endometrial carcinomas also exhibiting a type I aberration profile, whereas carcinosarcomas with a type II carcinoma differentiation had karyotypic abnormalities similar to those of type II endometrial carcinomas.

Cytogenetic and FISH analysis of endometrial carcinoma

Endometrial cancer is a common gynecologic tumor, yet reports of cytogenetic studies are few. We studied chromosomes from seven primary specimens of endometrial cancer. Six had abnormal chromosomes; five had a diploid-hyperdiploid modal number and one was triploid. One specimen had a normal karyotype. Chromosome 1 was frequently involved in abnormalities (five tumors) with i(1q) in two tumors, and one tumor each had der(7)t(1;7)(q12;p11) and +add (1)(p13). One additional tumor had trisomy 1 in the single cell which could be fully analyzed. Trisomy 7 was noted in two tumors, and trisomy 10 in one. Because trisomies of these chromosomes have been reported in other cases of endometrial cancer, we used fluorescent in situ hybridization (FISH) with centromere probes to determine the prevalence of trisomies 7 and 10 in these specimens. No additional tumors were found to have trisomies 7 or 10 by FISH. Our data, in combination with published literature, suggest that additional copies of 1q or portions of 1q constitute the primary change in this tumor. Extra copies of genes in this region may play an important role in tumorigenesis in endometrial carcinoma.

Two cell lines established from mixed müllerian tumors of the uterus. Morphologic, immunocytochemical, and cytogenetic analyses

To clarify the cellular origin and characteristics of malignant mixed müllerian tumor (MMMT), the authors investigated two cell lines (designated as FU-MMT-1 and FU-MMT-2) established from two patients with heterologous MMMT of the uterus. Both cell lines propagated continuously for 83 and 55 serial passages over 1.5 years, respectively. Morphologically, FU-MMT-2 was a mixture of carcinoma cells and sarcoma cells with predominance of carcinoma cells; FU-MMT-1 only had a sarcomatous element with distinct rhabdomyoblastic differentiation. Immunocytochemically, the sarcoma cells of each cell line expressed, not only myogenic and mesenchymal antigens (desmin, myoglobin, and vimentin), but also epithelial antigens, including epithelial membrane antigen and keratin. The carcinoma cells in FU-MMT-2 were positive for the epithelial antigens and vimentin and negative for desmin and myoglobin. Both lines had abnormal karyotypes; the modal chromosome numbers of FU-MMT-1 and FU-MMT-2 were 47 and 80, respectively. In addition, FU-MMT-1 had trisomy 8, and FU-MMT-2 had complex structural abnormalities. When transplanted into nude mice, FU-MMT-1 reproduced and maintained the characteristics of the original tumor. These cell lines and xenografts appear to provide a useful system for studying the biologic behavior, cytogenetic features, and histogenesis of MMMT. In conclusion, the presence of epithelial antigens in the sarcomatous and carcinomatous elements seemed to support the hypothesis that both elements are derived from a common stem cell.

Partial trisomy 1q in idiopathic myelofibrosis

Three cases of idiopathic myelofibrosis with partial trisomy of the long arm of chromosome 1 are described. Partial trisomy 1q was the only karyotypic change detectable in unstimulated peripheral blood cell cultures of one and bone-marrow cultures of two patients at diagnosis. The extra segment from chromosome 1 was located on different karyotype sites, i.e. 1qter, 1p34 and 6p22-23; 1q21-32 was the shortest overlapping region and the only trisomic segment in one of the three patients. These findings suggest that partial trisomy 1q is a primary chromosome aberration in myelofibrosis relevant in the pathogenesis of this hematologic disorder.