1/12. Unique cytological features and chromosome aberrations in chondroid lipoma: a case report based on fine-needle aspiration cytology, histopathology, electron microscopy, chromosome banding, and molecular cytogenetics.Chondroid lipoma is a rare, benign tumor that may mimic soft-tissue sarcoma clinically. Its histopathologic features may resemble hibernoma, myxoid liposarcoma, myxoid chondrosarcoma, and other lipomatous or chondroid neoplasms. In this study, a chondroid lipoma was analyzed by fine-needle aspiration cytology, histopathology, electron microscopy, chromosome banding, and metaphase fluorescence in situ hybridization. The results demonstrate that chondroid lipoma exhibits a characteristic pattern by fine-needle aspiration cytology, including a mixture of benign adipose tissue with lipoblastlike cells, and chondroblastlike cells with a fibrochondroid matrix. Cytogenetically, a three-way rearrangement between chromosomes 1, 2, and 5 was found, together with an 11;16 translocation with a breakpoint in 11q13, approximately 1 Mb proximal to the MEN1 region shown to be rearranged frequently in hibernoma. The presence of a karyotype of low complexity, but without any of the genetic aberrations characteristic for other types of soft-tissue tumors, indicate that chondroid lipoma develops along a unique pathogenetic pathway.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/12. A t(2;19)(p13;p13.2) in a giant invasive cardiac lipoma from a patient with multiple lipomatosis.Cardiac lipomas occur infrequently but account for a significant portion of rare cardiac tumors. Common cutaneous lipomas have previously been associated with rearrangements of chromosome band 12q15, which often disrupt the high-mobility-group protein gene HMGIC. In this report, we describe the cytogenetic analysis of an unusual giant cardiac lipoma that exhibited myocardial invasion in a patient with a history of multiple lipomatosis (cutaneous lipoma, lipomatous gynecomastia, lipomatous hypertrophy of the interatrial septum, and dyslipidemia). Cytogenetic studies of cells derived from the cardiac lipoma demonstrated no abnormalities of chromosome 12, but did reveal a t(2;19)(p13;p13.2). A liposarcoma-derived oncogene (p115-RhoGEF) previously mapped to chromosome 19 and the low-density lipoprotein receptor gene (LDLR) previously mapped to chromosome band 19p13 were evaluated to determine whether they were disrupted by this translocation. fluorescence in situ hybridization analyses assigned p115-RhoGEF to chromosome 19 in bands q13.2-q13.3 and mapped the LDLR to chromosome arm 19p in segment 13.2, but centromeric to the t(2;19) breakpoint. Thus, these genes are unlikely to be involved in the t(2;19)(p13;p13.2). Further studies of the regions of chromosomes 2 and 19 perturbed by the translocation in this unusual infiltrating cardiac lipoma will identify gene(s) that participate in adipocyte growth and differentiation and may provide insight into syndromes of multiple lipomatosis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/12. Evidence by spectral karyotyping that 8q11.2 is nonrandomly involved in lipoblastoma.We report two cases of lipoblastoma with chromosome 8-related aberrations, ie, a 92,XXYY,t(7;8Xp22;q11.2)x2 [8]/46,XY[16] in Case 1 and a 46,XY,-8,-13,add(16) (q22), mar, r [cp13]/46,XY[7] in Case 2. Using spectral karyotyping and fluorescence in situ hybridization techniques, the karyotype of Case 2 was redesignated as 46,XY, r(8), del(13)(q12), der(16)ins(16;8)(q22; q24q11.2)[cp13]/46,XY[7]. This report delineates a new chromosome rearrangement, ie, der(16)ins(16;8)(q22; q24q11.2) in lipoblastoma, and also confirms the t(7; 8)(p22;q11.2), reported only once previously, as a recurrent translocation involved in such a tumor. These findings provide valuable information for clinical molecular cytogenetic diagnosis of lipoblastoma. Furthermore, this report highlights the value of cytogenetic and molecular cytogenetic analysis in differential diagnosis of childhood adipose tissue tumors and adds to the number of lipoblastomas reported with chromosomal abnormalities at 8q11.2.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/12. Rearrangement involving chromosomes 1 and 8 in a retroperitoneal lipoma.Superficial lipomas are very common benign adipose tissue tumors. In contrast, deep-seated lipomas such as retroperitoneal lipomas, are extremely rare and have to be carefully distinguished from well-differentiated liposarcomas for appropriate treatment and follow-up. We report to, our knowledge, the first cytogenetic analysis of a retroperitoneal lipoma occurring in an adult, which showed a complex rearrangement interpreted as t(1;8)(q32;q22-q23) followed by a pericentric inversion of der(8). There was no detectable rearrangement of chromosome 12, and in particular no 12q14-q15 amplification. Because rearrangements of the 8q11-q13 region involving the PLAG1 gene have been described in lipoblastoma-another kind of benign adipose tumor--we used fluorescence in situ hybridization analysis to determine in the present case the chromosomal breakpoint on 8q was located between the ETO (8q22) and COX6C (8q22-q23) genes at a great distance from PLAG1. Karyotypic analysis of additional cases of retroperitoneal lipomas will be required to assess the significance of chromosome 1 and 8 rearrangements in a continuous effort to attain a better classification of adipose tissue tumors. Of great importance is the determination of such genetic markers as additional tools for the differential diagnosis between benign and malignant forms of adipose tumors, and to avoid erroneous diagnoses.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/12. Atypical lipomatous tumor in a 14-year-old patient: distinction from lipoblastoma using FISH analysis.Liposarcomas are rare in young age. We present the rare case of an atypical lipomatous tumor (synonym: well-differentiated lipoma-like liposarcoma) in a 14-year-old girl with the differential diagnosis of lipoblastoma which was excluded by fluorescence in situ hybridization (FISH) analysis. The tumor presented as a soft tissue mass at the dorsal part of the right thigh measuring up to 18 cm. Microscopically the lesion consisted of atypical adipocytes with hyperchromatic nuclei and additional multivacuolated lipoblasts. interphase dual-color FISH performed with chromosome 8 centromeric and YAC164H5 (mapping to exons 2-5 of the PLAG1 gene) probes revealed no rearrangement of PLAG1 oncogene or polysomy of chromosome 8. Additional FISH using an MDM2 gene probe and an BAC534N15 probe (containing sequences specific for the CDK4 gene) showed amplification of the CDK4 gene. These findings indicate that this tumor was no lipoblastoma but an atypical lipomatous tumor, which is of clinical relevance. In young individuals the distinction between lipoblastoma and liposarcoma is often impossible by light microscopy alone. This case shows that FISH can serve as a decisive tool in the differential diagnosis of lipoblastoma and lipoma-like liposarcoma apart from its role in distinction between lipoblastoma and myxoid/round cell liposarcoma.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/12. Infiltrating intramuscular lipoma of the temporal muscle. A case report with molecular cytogenetic analysis.Intramuscular lipomas are uncommon benign mesenchymal tumors which infiltrate skeletal muscle and are exceedingly rare in the head and neck region. Because of the infiltrating nature of the lesion and a high propensity for recurrence, they are sometimes difficult to distinguish from well-differentiated liposarcomas (WDLS). We report, the first case of an infiltrating lipoma of the temporal muscle in a 62-year-old white man who presented with a slow growing mass in the left temporal region. The histopathological examination showed diffuse infiltration of the striated muscle fibers by mature adipocytes. There were no lipoblasts or cells with atypical nuclei as described in WDLS. We performed interphase fluorescence in situ hybridization (FISH) analyses using painting probes for chromosome 12 and a specific probe for the MDM2 gene and comparative genomic hybridization. The results did not identify MDM2 or 12q amplification and therefore confirmed the benign nature of the lesion.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
7/12. lipoblastoma in a 23-year-old male: distinction from atypical lipomatous tumor using cytogenetic and fluorescence in-situ hybridization analysis.lipoblastoma is a rare benign tumor that occurs primarily in infancy and early childhood. We present the rare presentation of a 12 cm sized intramuscular lipoblastoma of the thigh in a 23-year-old patient. On histology, the tumor strongly resembled an atypical lipomatous tumor due to the presence of lipoblasts and atypical stromal nuclei. The very focal lobulation and myxoid change presented the only histological hint towards a lipoblastoma. Cytogenetic and subsequent FISH evaluation of the tumor cells showed a 46,XY, t(8;15) (q12;q25) as chromosomal change with rearrangement of the PLAG1 gene. The present case indicates that lipoblastoma should enter the differential diagnosis of an 'atypical' deep seated fatty tumor in adults. The diagnostic value of cytogenetic/molecular analysis in the differential diagnosis of lipomatous tumors is underscored as well.- - - - - - - - - - ranking = 4keywords = hybridization (Clic here for more details about this article) |
8/12. 11q13 alterations in two cases of hibernoma: large heterozygous deletions and rearrangement breakpoints near GARP in 11q13.5.Hibernomas are rare, benign tumors with a histological appearance resembling that of brown adipose tissue. The diagnosis of hibernomas may be difficult because some of them contain only a small number of the characteristic multivacuolated fat cells and can be mistakenly classified as well-differentiated liposarcomas. Cytogenetic information has been reported for 10 cases, showing that these tumors are characterized by structural rearrangements involving 11q13. Previous fluorescence in situ hybridization (FISH) studies revealed consistent and sometimes cryptic losses of the MEN1 region in 11q13.1. Here, we describe the molecular cytogenetic analysis of two new hibernoma cases. Both tumors showed complex rearrangements, simultaneously including translocations, inversions, and deletions affecting the pair of chromosomes 11. The translocation partners were chromosome 5 in one case and chromosomes 16 and 22 in the other case. The 11q13 region was concomitantly rearranged on both chromosomes 11. FISH studies revealed large heterozygous deletions within the 11q13 band, from 11q13.1 to 11q13.5. genes such as PYGM, MEN1, CCND1, FGF3, ARIX, and GARP were deleted, showing that the size of the 11q13 altered region was larger than previously reported. Furthermore, both tumors had breakpoints in 11q13.5, one of them in the immediate proximity of the GARP gene. Our results suggest that rearrangements of GARP or a neighboring gene may be important for the pathogenesis of hibernomas.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/12. Atypical lipomatous tumor with rare structural rearrangements involving chromosomes 8 and 12.Atypical lipomatous tumor (ALT), an intermediate malignant neoplasm of soft tissues, is characterized by the presence of supernumerary ring and giant marker chromosomes. These supernumerary chromosomes consistently contain amplified 12q-material in association with amplified segments from a variety of other chromosomes. However, a few cases of ALT with other types of chromosomal rearrangements have been reported earlier. We report on new types of structural aberrations in a case of ALT. In a pseudodiploid karyotype, there were two aberrant chromosomes, both consisting of alternating chromosome 8 and 12 sequences as shown by multicolor fluorescence in situ hybridization (FISH). The complex rearrangement was not only the result of multiple breaks and reunions of these chromosomes, but was also associated with a gain of chromosome 12 sequences. FISH analyses revealed that the number of MDM2 signals was slightly elevated (median, 5). There were three intact copies of HMGA2 and one additional copy of the 5' part of the gene. These findings are consistent with previous reports that the ALT phenotype may be associated with a low or moderate level of gene amplification, whereas truncation of HMGA2 has been observed in both ALTs and benign lipomas. The aberrations in the present case were stable, although rare cells with higher MDM2 copy numbers were detected. Whether ALTs with these types of aberrations have a lower risk of tumor progression than ALTs with the notoriously mitotically unstable ring and giant marker chromosomes remains to be investigated.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/12. Extramammary myofibroblastoma is genetically related to spindle cell lipoma.Extramammary-type myofibroblastoma is a rare, benign spindle cell lesion, strictly resembling the breast counterpart, but occurring in extramammary sites, mainly in the inguinal/groin area. In this paper, we describe an extramammary-type myofibroblastoma in the groin of a 37-year-old male patient. The tumor showed a typical morphological and immunophenotypical profile, including staining for both CD34 and desmin. Dual-color interphase florescent in situ hybridization analysis revealed losses of RB/13q14 and FKHR/13q14 loci within tumor cells. The chromosome 13 rearrangements associated with the loss of the 13q14 chromosomal region are typically seen in spindle cell lipoma, and have been previously recognized in mammary myofibroblastoma, providing strong evidence for a pathogenetic link between these lesions.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
| | Next -> |