1/18. Renal angiomyolipoma resembling gastrointestinal stromal tumor with skenoid fibers.We report an unusual case of renal angiomyolipoma occurring in 68-year-old man. The tumor lacked well-developed vascular and adipose components and was composed almost exclusively of smooth muscle cells. Numerous skenoid-like periodic acid-Schiff-positive globules were interspersed between the tumor cells; the lesion therefore closely resembled a low-grade stromal tumor of the gastrointestinal tract. The HMB45-positive/CD34-negative immunophenotype was essential for the diagnosis of angiomyolipoma. Neither gastrointestinal tumor nor any signs of tuberous sclerosis were found. This lesion should be included in the list of morphologic variations of angiomyolipoma, which may cause diagnostic difficulties.- - - - - - - - - - ranking = 1keywords = acid (Clic here for more details about this article) |
2/18. Vacuolated cell mesothelioma of the pericardium resembling liposarcoma: a case report.We report a case of localized pericardial mesothelioma with unusual histological features in a 44-year-old woman. Her radiological imagings showed an 11-cm pericardial tumor, between the heart and aortic arch. Microscopically, the tumor was predominantly composed of vacuolated cells and vaguely reminiscent of well differentiated "lipoma-like" liposarcoma, but only small foci of the tumor showed the papillotubular configuration. Histochemically, the tumor cells contained hyaluronic acid in the vacuoles but no lipids. Immunohistochemically, they showed immunoreactivity for cytokeratin, calretinin, vimentin, and epithelial membrane antigen. Ultrastructural study showed that the vacuoles of the tumor cells were intracytoplasmic lumina. The intracytoplasmic lumina and the surface membranes of the tumor cells had many long and slender microvilli with focal bush-like appearance. desmosomes between adjacent cells were occasionally observed. To our knowledge, this is the first case report of epithelial type mesothelioma predominantly composed of vacuolated tumor cells, microscopically mimicking liposarcoma.- - - - - - - - - - ranking = 1keywords = acid (Clic here for more details about this article) |
3/18. Characterization of centromere alterations in liposarcomas.Supernumerary ring and large marker chromosomes are a characteristic of atypical lipomas and well-differentiated liposarcomas (ALP-WDLPS) and are composed of amplified 12q14-15 sequences in association with variable segments from other chromosomes. Although stably transmitted, these chromosomes contain centromeric alterations, showing no detectable alpha-satellite sequences. We performed C-banding, fluorescence in situ hybridization, and immunostaining with anti-centromere antibodies in 8 cases of liposarcomas with supernumerary rings and large markers, including 5 ALP-WDLPS and 3 dedifferentiated-LPS and high-grade LPS. Our results with alpha-satellite probes and anti-CENPB antibodies confirm the lack of detectable alpha-satellite sequences in the five ALP-WDLPS supernumerary chromosomes, whereas centromeric activity was proved by the detection of kinetochores by using anti-CENPC antibodies. In contrast, the high grade and dedifferentiated liposarcomas showed a different pattern. In 2 cases, amplified chromosome 12 sequences, including amplification of alpha-satellite 12 sequences in 1 case, were present on chromosomes with typical centromeres. In another case, the rings were similar to WDLPS-ALP rings, but a large marker contained a chromosome 5 centromere and amplified alpha-satellite sequences from chromosome 8. ALP-WDLPS is the first example of a tumor class for which the presence of stable analphoid chromosomes is a constant and specific abnormality. Formation of newly derived centromeres, so-called neocentromeres, could be an original and effective way to maintain a selective advantage in neoplastic cells by conferring stability to the supernumerary chromosomes of ALP-WDLPS. The activation of normally non-centromeric sequences might be obtained by an epigenetic mechanism due to the peculiar chromatin conformation of these highly complex chromosomes.- - - - - - - - - - ranking = 59487.061732615keywords = amplification (Clic here for more details about this article) |
4/18. Dedifferentiation of a well-differentiated liposarcoma to a highly malignant metastatic osteosarcoma: amplification of 12q14 at all stages and gain of 1q22-q24 associated with metastases.Well-differentiated liposarcomas (WDLPS), especially those located in the retroperitoneum, may occasionally undergo dedifferentiation. Although this process is associated with a more aggressive clinical course, dedifferentiated liposarcomas rarely produces metastases. The case reported here is rather uncommon: A retroperitoneal WDLPS gave lung metastases that were diagnosed as highly malignant osteosarcomas. We used comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), and Southern blot analyses to characterize the copy number changes and genetic aberrations occurring at different stages of the disease. In the primary tumor, the only detectable aberration was amplification of 12q13-q14, which was present only in a fraction of the cells and revealed by FISH analysis. High-level amplification of 12q13-q14, involving CDK4, MDM2, and HMGIC, was seen both in the relapse and the metastases. The second most common change, gain or high-level amplification of 1q22-q24, was detectable by CGH only in the osteogenic metastases, as was loss of the distal 2q. FISH analyses revealed considerable heterogeneity in the samples, and the percentage of cells showing aberrations was significantly higher in the metastatic samples. In particular, increased copy numbers of 789f2, a marker for 1q21 amplification in sarcomas, was observed in more than 65% of the cells in the metastatic samples, but in less than 10% of the cells from the recurrent samples. These observations could indicate that 1q amplification, in particular, may be indicative of a more malignant phenotype and ability of metastasis in WDLPS, as has also been suggested by others.- - - - - - - - - - ranking = 535383.55559354keywords = amplification (Clic here for more details about this article) |
5/18. MDM2 /CDK4 /p53 oral liposarcoma: case report and review of the literature.Although liposarcoma is one of the most common soft tissue sarcomas, its location in the oral cavity is very rare. To our knowledge, only 43 cases of liposarcoma originating in the oral tissues have been reported in the English-language literature. In this article, we report a case of well-differentiated liposarcoma affecting the cheek of a 28-year-old man and review the oral liposarcoma literature. Immunohistochemical analysis of the tumor revealed an MDM2 /CDK4 /p53 immunophenotype that is consistent with the immunohistochemical profile of well-differentiated liposarcoma originating in other areas of the body. Quantitative polymerase chain reaction analysis of the dna levels of the MDM2 (human homologue of the murine double-minute type 2), CDK4 (cyclin-dependent kinase 4), and SAS (sarcoma amplified sequence), genes was performed, revealing only SAS gene amplification. The possibility of misdiagnosis of oral liposarcoma because of its sometimes inconspicuous clinical and microscopic features is emphasized. Careful pathologic examination of liposarcoma is essential for discrimination from benign adipose tissue neoplasms and for precise histologic classification, both of major prognostic significance. Possible implications of molecular and cytogenetic analysis for unraveling the pathogenesis and determining the prognosis of liposarcoma are discussed.- - - - - - - - - - ranking = 59487.061732615keywords = amplification (Clic here for more details about this article) |
6/18. Distinction between lipoma and liposarcoma by MDM2 alterations: a case report of simultaneously occurring tumors and review of the literature.We investigated a lipoma and a well-differentiated/dedifferentiated liposarcoma (WD/DDL), occurring simultaneously in one patient for the possible role of p53 and mdm2 in the molecular oncogenesis of liposarcoma and tumor progression. The hypothesis tested was if there is a continuum in the development from lipoma to liposarcoma. Lipoma was characterized by a lack of p53 mutation, p53 LOH and p53 protein expression, as well as by mdm2 amplification and mdm2 protein expression. p53 mutation and p53 LOH were found neither in the well-differentiated nor in the dedifferentiated parts of the liposarcoma. In contrast, mdm2 amplification and an increase in mdm2 protein expression were found to be associated with malignancy and dedifferentiation, whereas p53 protein expression was only slightly increased. These findings indicate that mdm2 constitutes one of the most common targets for molecular aberration in WD/DDL. We suggest that mdm2 is a marker distinguishing between ordinary lipoma and well-differentiated liposarcoma, and that the genesis of these tumors is different.- - - - - - - - - - ranking = 118974.12346523keywords = amplification (Clic here for more details about this article) |
7/18. Dedifferentiated liposarcoma with extensive lymphoid component.An unusual variant of dedifferentiated liposarcoma with extensive lymphocytic component is described. A 71-year-old patient suffered from a relapse of an atypical lipomatous tumor/well-differentiated liposarcoma with early micronodular (low-grade) dedifferentiation, which had been resected 4 years before. The relapse revealed features of a dedifferentiated liposarcoma with spindle-cell, partly pleomorphic dedifferentiation and osseous metaplasia. Clearly separated from the spindle-cell areas, an extensive homogeneously dense lymphoid (lymphocytic) tumor-component was evident, with relative abrupt transition to the well-differentiated liposarcoma component. Using immunohistochemistry and PCR, the lymphoid ("lymphoma-like") infiltrate proved to be a polyclonal lymphocytic proliferation. fluorescence in situ hybridization (FISII) analysis revealed no signs of MDM2- and CDK4-gene amplification in the lymphoid areas, although within this mononuclear lymphoid population, large polymorphic nuclei displayed an amplified number of MDM2/CDK4 gene copies, indicating the presence of truly dedifferentiated tumor cells within the lymphoid component. The results favor a reactive lymphocytic infiltration versus a neoplastic one, which might be caused for example by chemoattractive agents. An extensive lymphoid "overgrowth" must be considered within the spectrum of unusual variants and in the differential diagnosis of dedifferentiated liposarcoma.- - - - - - - - - - ranking = 59487.061732615keywords = amplification (Clic here for more details about this article) |
8/18. Uterine liposarcoma in a young woman: a case report.liposarcoma of uterus is a very rare neoplasm encountered generally in the sixth or seventh decade of life. We reported the eighth case of uterine liposarcoma with extension to broad ligament in a 23-year-old woman who presented with pelvic pain, dysuria, and rapidly enlarging pelvic mass. During laparotomy, the mass was detected to be originated from the uterine cervix. In frozen section, no definitive diagnosis was established, and for preservation of fertility, extirpation of the mass was performed. The histopathologic examination of the specimen revealed liposarcoma. The tumor cells were diffusely and intensively immune reactive for vimentin and S-100, and negative for smooth muscle actin, desmin, h-caldesmon, pan cytokeratin, and CD10. Staining with periodic acid and Schiff, alcian blue, mucicarmine, and epithelial membrane antigen (EMA) were negative. No recurrence was detected in the postoperative seventh month. Present case is the youngest patient with uterine liposarcoma and also the first case detected in reproductive period.- - - - - - - - - - ranking = 1keywords = acid (Clic here for more details about this article) |
9/18. Retroperitoneal lipomatous angiomyolipoma associated with amyloid deposition masquerading as well-differentiated liposarcoma.Reported herein is a case of retroperitoneal angiomyolipoma associated with amyloid deposition, masquerading as well-differentiated liposarcoma. A 16 x 13 cm lipomatous tumor was resected from the perirenal retroperitoneum of a 71-year-old woman. Microscopically, the tumor was exclusively composed of mature adipose tissue and abnormal thick blood vessels, but bundles of smooth muscle were lacking. In addition, amyloid was deposited between fat cells. Initially, well-differentiated liposarcoma was highly suspected. However, there were a few epithelioid cells with clear vacuolated cytoplasm within the vessel walls, which were immunoreactive for smooth muscle markers and HMB-45. real-time polymerase chain reaction failed to demonstrate the amplification of the murine double-minute type 2 gene and cyclin-dependent kinase 4 gene in this tumor. Therefore, the tumor was diagnosed as lipomatous angiomyolipoma. After the diagnosis, it was found that the patient had multiple myeloma and cardiac amyloidosis, suggesting that the amyloid deposition within the tumor was a complication of the myeloma. Lipomatous angiomyolipoma may be a diagnostic pitfall of retroperitoneal lipomatous tumors.- - - - - - - - - - ranking = 59487.061732615keywords = amplification (Clic here for more details about this article) |
10/18. Formation of the 12q14-q15 amplicon precedes the development of a well-differentiated liposarcoma arising from a nonchondroid pulmonary hamartoma.Pulmonary hamartoma is a benign neoplasm that rarely recurs or undergoes malignant transformation. Herein, we report a 48-year-old woman with a history of an incomplete excised nonchondroid pulmonary hamartoma presenting as an indolent tumor recurrence. Excision of the tumor revealed a well-differentiated liposarcoma arising from the hamartomatous component. fluorescence in situ hybridation analysis for HMGA2 and MDM2 was performed on both hamartomatous and liposarcomatous component. MDM2 and HMGA2 amplification were found in a subset of stromal cells in the hamartomatous component and in most cells of the well-differentiated liposarcoma. No rearrangement HMGA2 was found in the pulmonary hamartoma component. These findings suggest that the formation of the 12q14-q15 chromosome amplicon, the characteristic cytogenetic finding of well-differentiated liposarcomas and the structural genomic component of the supernumerary ring and giant rod chromosomes, occurred before the morphologic changes characteristic of these malignant adipose tissue tumors and likely represents a very early molecular event in their development.- - - - - - - - - - ranking = 59487.061732615keywords = amplification (Clic here for more details about this article) |
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