Cytogenetic analysis of sinonasal carcinomas.

BACKGROUND: Sinonasal carcinomas, including nonkeratinizing (NK) squamous cell carcinoma (SCC) and sinonasal undifferentiated carcinoma (SNUC), are uncommon malignant neoplasms arising from the Schneiderian respiratory epithelium of the nasal cavity and paranasal sinuses. Due to their low frequency, the cytogenetic data on these tumors is limited. METHODS: Seventeen patients who were operated on in our institution for extirpation of paranasal carcinomas were enrolled in this study. Fourteen pathologically confirmed samples of sinonasal carcinomas were cytogenetically analyzed using G-banding techniques after short-term culture. Three samples did not grow on culture. RESULTS: Five of the 14 sinonasal carcinomas had an abnormal karyotype (36%). Of the 9 NK SCCs, 3 had abnormal karyotypes with numerical and structural chromosomal anomalies. Of the 5 patients with SNUC, 2 had an abnormal karyotype. One case of SNUC had a diploid complex karyotype. Another case of SNUC had a near triploid composite karyotype with 60-69 chromosomes. The chromosome arms that involved frequent breakpoint and rearrangements were: 1p, 6p, 7p, and 12q. We found that 3 of the 3 patients who died of disease displayed an abnormal karyotype, whereas 2 of the 11 patients who are alive displayed an abnormal karyotype (P = 0.027). CONCLUSIONS: The study revealed that more than a third of the paranasal carcinomas carry an abnormal karyotype. No specific common aberrations were found in these tumors. To our knowledge this is the first attempt to investigate sinonasal squamous and undifferentiated carcinomas on a genetic level using G-banding technique. Additional studies are required in order to determine whether cytogenetic data may serve as an adjunct to conventional pathology for the diagnosis and prognosis assessment of these rare and highly aggressive tumors.

Cytogenetic analysis of three variants of clival chordoma.

Chordoma is an uncommon malignant neoplasm derived from remnants of the embryonal notochord. The tumor arises in the sacrococcygeal region in most cases. Cytogenetic information on clival chordomas is scarce due to the low incidence of these tumors. In this study, we applied the G-banding and spectral karyotyping techniques to compare the karyotypes of three variants of clival chordoma: conventional, chondroid, and dedifferentiated. We describe a normal karyotype of a chondroid chordoma and a complex karyotype of a conventional chordoma involving chromosomes 1, 2, 3, 5, 8, 9, 11, 15, 19, 20, and X. The cytogenetic analysis of the dedifferentiated chordoma showed a polyploid complex karyotype of 71-123 chromosomes with double minutes that originated from chromosome 17.

Predictive value of TP53 fluorescence in situ hybridization in cytogenetic subgroups of acute myeloid leukemia.

Acute myeloid leukemia (AML) with a complex karyotype (CK) has frequent alterations in TP53 and a very poor prognosis. We examined whether a prompt and simple fluorescence in situ hybridization (FISH) analysis for 17p13 deletion at diagnosis has a predictive value for response to therapy and overall survival in subgroups of AML. In 15 patients with a normal karyotype the TP53 FISH analysis was normal, whereas in 16 patients with CK 75% had only one copy of the TP53 allele. The deletion was also detected in 33% of six patients with monosomy or partial monosomy of chromosome 5, 7, 9, or 12. This loss of TP53 correlated significantly with a poor response to chemotherapy, and the median survival time of these patients was shorter. TP53 FISH analysis carried out at diagnosis has a predictive value with respect to chemotherapy response and can therefore facilitate a rapid decision on treatment strategies.

Cytogenetic analysis of 101 skull base tumors.

BACKGROUND: Skull base tumors are rare neoplasms and the cytogenetic data on these tumors are limited. The authors cytogenetically analyzed a large series of tumors and compared the findings with patients' pathologic data. METHODS: The karyotypes of pathologically confirmed samples of 101 patients, who were operated for oncological extirpation of tumors, were analyzed using G-banding and spectral-karyotyping techniques. RESULTS: Of the 67 malignant tumors, 32 (48%) had chromosomal aberrations, some with complex numerical and structural chromosomal anomalies. Recurrent chromosomal breakpoints were identified in squamous cell carcinomas, adenoid cystic carcinomas (ACCs), sinonasal undifferentiated carcinomas, chordomas, and sarcomas. Specific breakpoints established the diagnosis of various soft tissue sarcomas. Novel chromosomal aberrations were found in various other malignant and benign tumors. CONCLUSION: This study highlights the value of cytogenetic analysis for diagnosis of skull base tumors. The data add further information on the biological behavior of these rare neoplasms.

The clinical application of spectral karyotyping (SKY) in the analysis of prenatally diagnosed extra structurally abnormal chromosomes (ESACs).

OBJECTIVE: The prenatal detection of de novo extra structurally abnormal chromosomes (ESACs) presents a challenge because the associated risk for congenital anomaly ranges from 100% to practically none, depending on the chromosomal origin. Despite the use of standard cytogenetic techniques and even fluorescence in situ hybridization (FISH), the origin of some ESACs often remains elusive. Spectral karyotyping (SKY) is a molecular cytogenetic technique based on the simultaneous analysis of all chromosomes using a unique probe mix that allows the rapid identification of all chromosomes in 24 colors. The purpose of this study was to evaluate the use of SKY in the characterization of prenatally diagnosed de novo ESACs. METHODS: This series includes five cases of de novo ESACs detected prenatally in routine amniocentesis samples performed for advanced maternal age. Cases of inherited ESACs or ESACs defined by standard cytogenetic techniques were excluded. RESULTS: SKY analysis yielded valuable information, particularly in cases of nonsatellited ESACs: a der(18) and a ring(Y). In a case of a unisatellited der(15), SKY corroborated data obtained by standard cytogenetic techniques and FISH. Finally, in two cases of small bisatellited chromosomes, SKY was noncontributory. CONCLUSIONS: While SKY may be a valuable tool in some cases, especially nonsatellited and ring ESACs, it does have limitations and should be used judiciously in conjunction with other cytogenetic techniques.