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PubMed2000

Comparative 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin uptake in human soft tissue sarcoma cell lines.

The uptake characteristics of technetium-99m hexakis-2-methoxyisobutylisonitrile (MIBI), 99mTc-tetrofosmin and 99mTc-furifosmin in human soft tissue sarcoma cell lines were investigated and compared. After 10-120 min of incubation at 37 degrees C, 32 degrees C and 22 degrees C with 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin, the kinetics of cellular uptake of these tracers in human soft tissue sarcoma cells SW 684 (fibrosarcoma), SW 872 (liposarcoma), SW 982 (synovial sarcoma) and SW 1353 (chondrosarcoma) was assessed. The uptake of 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin was temperature dependent. The kinetics of uptake of 99mTc-MIBI and of 99mTc-tetrofosmin was similar between fibrosarcoma and liposarcoma cells, as well as between synovial sarcoma and chondrosarcoma cells. 99mTc-furifosmin showed similar uptake kinetics in all cell lines. The uptake of 99mTc-furifosmin was, however, significantly higher in liposarcoma than in the other cells. The data indicate that the cellular uptake of 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin is dependent on cellular metabolic activity.

Cell Survival↗
PubMed1992

Adipose tumors of soft tissues.

Thirteen patients with lipoma were examined at least with MRI, which revealed homogeneous and high signal lesions in both T1 and T2 WI sequences. On CT, these lesions were characterized by very negative density values. Sonography was useful to differentiate a lipoma from an old hematoma that share the same signal on MRI. Eighteen cases of biopsy proven liposarcomas were evaluated with at least two techniques. Tumor heterogeneity was the most important clue to malignancy. With CT, contrast injection was necessary because two cases out of eight appeared homogeneous on native examinations. Lobular pattern and large size are constant signs associated with liposarcoma. The correlation of imaging and histology classification was only successful with differentiated tumors. Angiography unspecifically reveals the malignancy of liposarcoma. MRI is better than CT to evaluate tumor expansion and to differentiate the mass from the surrounding tissue.

Adolescent↗
PubMed2005

Immunophenotypic characterization of high grade pleomorphic sarcomas: a demographic and immunohistochemical study in a major referral center of Pakistan.

OBJECTIVE: Immunophenotypic characterization of high grade (pleomorphic) sarcomas and determination of their frequency, mean/median age, sex preferences and common sites in Pakistani patients. METHODS: This study included 134 consecutive cases of high grade (pleomorphic) sarcomas diagnosed in adults above the age of 15 years in the section of histopathology at theAga Khan University Hospital, Karachi during a period of two years. These high grade (pleomorphic) sarcomas were immunophenotyped using a panel including antibodies against Vimentin, Desmin, Smooth muscle Actin, S 100, CD34, CD68 and Cytokeratin etc by indirect immunoperoxidase. RESULTS: Of the 134 cases which were characterized, 38.1% were pleomorphic leiomyosarcoma, followed by pleomorphic rhabdomyosarcoma 14.9%, Malignant Peripheral Nerve Sheath Tumour 9%, pleomorphic liposarcoma 3.7% and pleomorphic storiform Malignant Fibrous Histiocytoma 0.7%. Thirty three percent of cases could not be characterized further. Mean/ median age for Leiomyosarcoma was 50/50, for Rhabdomyosarcomas 33/22, for MPNST 42/41, for Liposarcoma 52/50 and for Malignant Fibrous Histiocytoma 46/46 respectively. The commonest site for leiomyosarcoma was lower limb (43%), for rhabdomyosarcoma head and neck (42%), for MPNSTthorax (36.4%) and for liposarcoma abdomen (50%). CONCLUSION: It was concluded that the most common pleomorphic sarcoma occurring in our adult population was Leiomyosarcoma, and that immunohistochemical stains are essential in most cases for further characterization of pleomorphic high grade sarcoma.

Adult↗
PubMed1989

Immunocytochemical diagnosis of skin tumours of the dog with special reference to undifferentiated types.

Immunoperoxidase techniques for S-100 protein, keratin, cytokeratin, vimentin and desmin were applied to 65 canine skin tumours. These included eight squamous cell carcinomas, eight fibrosarcomas, eight melanomas, eight mastocytomas, eight haemangiosarcomas, eight leiomyosarcomas, five liposarcomas and 12 poorly differentiated tumours. Consistent results were obtained within each group. Cytokeratin and keratin immunoreactivity was detected only in squamous cell carcinomas. Vimentin was present in fibrosarcomas, melanomas, haemangiosarcomas, mastocytomas, leiomyosarcomas and liposarcomas. S-100 protein immunoreactivity was detected in melanomas, haemangiosarcomas, liposarcomas and leiomyosarcomas. Only leiomyosarcomas were positive for desmin. According to these results the 12 anaplastic tumours were diagnosed either as carcinomas, fibrosarcomas or malignant melanomas.

Animals↗
PubMed1987

Malignant fibrous histiocytoma. Evidence of perivascular mesenchymal cell origin immunocytochemical studies with monoclonal anti-MFH antibodies.

Using whole cell antigens prepared from the established lines of human malignant fibrous histiocytoma (MFH), the authors have generated two different monoclonal antibodies (FU3 and FU4) by a mouse hybridoma technique. By indirect immunoperoxidase in frozen tissue sections, FU3 and FU4 revealed strong staining of perivascular mesenchymal cells and fibroblasts. In the spleen FU3 stained perivascular cells of the ellipsoids and the marginal zone of the lymph follicles. Macrophages in granulation tissues as well as monocytes and other blood cells in normal peripheral blood were uniformly negative for the antigen detected by FU3. Among various soft-tissue tumors, MFH and liposarcoma reacted strongly with FU3 and FU4, but synovial sarcoma revealed no reaction with either of the antibodies. Immunoelectron-microscopic studies demonstrated positive reactions with FU3 and FU4 on the surface of MFH cell membrane, which suggests that these antibodies recognized cell surface antigens. In conclusion, MFH shares antigenicity with perivascular mesenchymal cells and fibroblasts as well as liposarcoma. MFH and liposarcoma may have a common origin from the perivascular mesenchymal cells that are supposed to have a potential for multidirectional differentiation.

Animals↗
PubMedDate not supplied

The combination of a decision tree technique with the computer-assisted microscope analysis of Feulgen-stained nuclei to assess aggressiveness in lipomatous and smooth muscle tumors.

The present study describes a computer-assisted methodology whose purpose is to reduce the degree of subjectivity in the diagnosis of soft tissue tumors. This methodology associates three complementary techniques, namely digital cell image analysis, the discretisation of numerical data and a Decision Tree technique (DT). The first technique relies on the use of the digital cell image analysis of Feulgen-stained nuclei, a technique which makes possible a quantitative and thus objective description of nuclei with the help of 24 numerical parameters (15 morphonuclear and 9 DNA content- (ploidy level and proliferation activity) related). The second technique transforms each numerical parameter into an ordinal one with a small number of values (2 to 4) so that only the relevant physical significance of the parameters is retained. The Decision Tree technique generates classification rules on the basis of the discretised parameters quoted above. This methodology was applied to 53 human soft tissue tumors which included 26 lipomatous tumors (13 malignant liposarcomas and 13 benign lipomas) and 27 smooth muscle tumors (11 malignant leiomyosarcomas and 16 benign leiomyomas). The results show that a distinction between benign (lipoma) and malignant (liposarcoma) lipomatous tumors can easily be made by means of simple logical rules depending on only four discretised cytological parameters (two ploidy- and two morphonuclear-related). In contrast, no stable or predictive characterisation can be obtained with respect to the difference between leiomyosarcomas and the leiomyomas. Hence, while lipomas and liposarcomas appeared to be two completely distinct biological entities, leiomyomas and leiomyosarcomas seem to involve a continuous biological process.

Cell Nucleus↗
PubMedDate not supplied

Antitumor chemosensitivity differs between clinical sarcoma and adenocarcinoma tissues.

The chemosensitivity of 43 human sarcoma tissues, including 18 osteosarcomas, 16 leiomyosarcomas and 9 liposarcomas, was compared with that of 28 adenocarcinomas of the stomach, using the in vitro succinate dehydrogenase inhibition (SDI) test. These tissues were exposed for 3 days to each antitumor drug, including adriamycin (ADM), 5-fluorouracil (5-FU), mitomycin C (MMC), cisplatin (CDDP), aclacinomycin A (ACR) and carboquone (CQ), them the cell viability was estimated based on the succinate dehydrogenase (SD) activity, determined using [3-(4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2H tetrazolium bromide] (MTT). SD activity was significantly lower in the osteosarcoma as compared to that in the adenocarcinoma, for ADM, MMC, CDDP, ACR and CQ (p < 0.01), and was higher for ADM (p < 0.05) in cases of leiomyosarcoma and for CDDP (p < 0.01) and ACR (p < 0.05) in cases of liposarcoma. The sensitivity rate was higher in osteosarcoma than in adenocarcinoma for ADM, MMC and CDDP. These findings suggest that patients with osteosarcoma will probably show a fairly good response to antitumor drugs, and that when liposarcoma or leiomyosarcoma tumors show resistance to antitumor drugs, then resection at the time of initial exploration and combined modalities, including radiation and hyperthermia, should be considered.

Adenocarcinoma↗
PubMed1996

The contribution of image cytometry and artificial intelligence-related methods of numerical data analysis for adipose tumor histopathologic classification.

Thirty-five lipomatous tumors were quantitatively described using 47 variables generated by means of computer-assisted microscope analysis. Of these 47 quantitative variables, 27 were computed on Feulgen-stained specimens (25 on cytologic and 2 on histologic samples) and, of the remaining 20, 8 related to vimentin and S-100 protein immunostaining patterns and the other 12 to the glycohistochemical staining patterns of peanut agglutinin, succinylated wheat germ agglutinin, and concavalin A agglutinin. The 35 lipomatous tumors included 6 atypical lipomas and 8 well differentiated, 5 dedifferentiated, 6 myxoid, and 10 pleomorphic liposarcomas. The actual diagnostic value contributed by each of the 47 variables with respect to the 5 lipomatous tumor groups was determined by means of the decision tree technique, an artificial intelligence-related algorithm that forms part of the supervised learning algorithms. Of the 47 quantitative variables, the decision tree technique retained 8: i.e., 2 tissue architecture-, 2 DNA ploidy level-, 2 morphonuclear-, 1 lectin histochemical-, and 1 vimentin immunostain-related variables. The decision tree technique made use of these 8 variables to set up logical rules that make it possible to identify atypical lipomas from well differentiated liposarcomas, on the one hand, and dedifferentiated liposarcomas from those that are well differentiated and pleomorphic, on the other. Thus, the combination of an artificial intelligence algorithm analyzing quantitative variables generated by means of the computer-assisted microscope analysis of cytologic and histologic samples from lipomatous tumors can be considered an expert system contributing significant diagnostic information to conventional diagnosis.

Algorithms↗
PubMed1996

[Determination of cellular DNA content in the diagnosis and prognosis of mesenchymal tumors].

The authors present examples on how to use cellular DNA distribution in support of diagnosis, and also to predict biological behavior of mesenchymal tumours. In cases of smooth muscle tumours of the prostate and the uterus, on the basis of histological pattern, it was not possible to distinguish between bizarre cell (pleomorph) leiomyoma and leiomyosarcoma. The prostate tumour showed an euploid polyploid cellular DNA distribution pattern, supporting the diagnosis of benign pleomorph leiomyoma. On the other hand, the uterus tumour showed an aneuploid DNA content with a high S-phase fraction that is characteristic of malignant lesions. Cellular DNA content analysis has helped to estimate the biological behavior of a gastrointestinal stromal tumour originating from the stomach and a retroperitoneal dedifferentiated type of a well differentiated liposarcoma. Small, diploid tumours (< 5 cm in diameter) with a low S-phase fraction behave like benign tumour or malignant tumour with a low malignant potential. The gastrointestinal stromal tumour was diploid with 8% S-phase ratio, therefore we could predict favorable outcome. It means that control examination is required less frequently. Prognostically, the dedifferentiated type of well-differentiated liposarcoma differs from the common well differentiated liposarcomas; the well differentiated part of this tumour consisted of only one diploid subpopulation with a low S-phase ratio, while the poorly differentiated areas contained a diploid and an aneuploid cell population with a significantly higher S-phase fraction than that of diploid one. Aneuploidy and rapid proliferation rate refer to increasing genetic instability, with a clonal selection for development of a more aggressive cell population, thus control examination is required more frequently.

Aged↗
PubMed2006

Genetic polymorphisms of the XPG and XPD nucleotide excision repair genes in sarcoma patients.

There are more than 50 subtypes of soft tissue sarcomas, among which 30% are associated with specific genetic alterations, including translocations. Several studies have reported associations between cancer risk and polymorphisms of DNA repair genes from the nucleotide excision repair (NER) pathway. NER involves more than 20 proteins whose inactivation leads to xeroderma pigmentosum (XP) or cockayne syndrome (CS), among which XPD, a helicase allowing DNA strand excision by the endonuclease XPG. DNA from 93 patients with synovial sarcomas, myxoid liposarcomas, dermatofibrosarcomas protuberans (DFSP), malignant fibrous histiocytomas and leiomyosarcomas were genotyped for both XPD Lys751Gln and XPG Asp1104His polymorphisms. Departure from Hardy-Weinberg was highly significant for the XPG polymorphism with an excess of heterozygotes in synovial sarcomas (p = 1.5 x 10(-5)), myxoid liposarcomas (p = 1.5 x 10(-4)) and to a lesser extent in DFSP (p = 0.028). In the case of XPD, a significant deviation was observed in synovial sarcomas (p = 3 x 10(-6)) and DFSP (p = 0.0014). When tumors were pooled according to their genetic alterations, the proportion of carriers of the variant XPG allele was significantly increased in sarcomas with specific translocations as compared to sarcomas with complex genetics (p < 10(-9)). No difference was found for XPD. Genotyping of the tumor samples in synovial sarcomas and myxoid liposarcomas revealed frequent loss of heterozygosity for XPG, mostly due to the loss of the frequent allele. For XPD, both alleles were lost with a similar frequency. Our results raise the potential implication of the XPG Asp1104His polymorphism in the occurrence of chromosomal translocations associated with specific subtypes of sarcomas.

Adolescent↗
PubMed1994

Hibernomas are characterized by rearrangements of chromosome bands 11q13-21.

Cytogenetic analysis revealed structural rearrangements of 11q13-21 in 9 lipogenic tumors--4 hibernomas, 4 typical lipomas and 1 mixed myxoid and well-differentiated liposarcoma. Two hibernomas and all lipomas simultaneously showed aberrations attributable to previously recognized cytogenetic subgroups among benign adipose tissue tumors, i.e., supernumerary ring chromosomes or rearrangements of 6p, 12q13-15, or 13q. The sole anomaly in the liposarcoma was a 4-way translocation t(9;11;22;12)(q21;q13;q11;q13), an aberration that has not previously been detected in either myxoid or well-differentiated liposarcomas. Together with our 4 cases, a total of 7 cytogenetically aberrant hibernomas have been reported. Five tumors have shown rearrangements of 11q13 and 2 of 11q21, indicating that this segment of chromosome 11 harbors one or more genes of importance in hibernoma development. Rearrangements of 11q13-21 also appear to be frequent in typical lipomas; a total of 8 typical lipomas with 11q13-21 changes have been described, including those in our series. In all but 1 however, breakpoints were also found in 6p, 12q13-15, or 13q.

Adult↗
PubMed1999

Microsatellite alterations in various sarcomas in Japanese patients.

To determine the usefulness of microsatellite analysis in the differential diagnosis of various sarcomas, we investigated microsatellite alterations at 12 microsatellite loci by polymerase chain reaction and electrophoresis in 39 Japanese patients with sarcomas. The sarcomas were: osteosarcoma, Ewing's sarcoma, chondrosarcoma, liposarcoma, leiomyosarcoma, epithelioid leiomyosarcoma, rhabdomyosarcoma, synovial sarcoma, and malignant fibrous histiocytoma. We also examined ten leiomyomas to contrast with leiomyosarcoma. No microsatellite instability (MSI) or loss of heterozygosity (LOH) were found in Ewing's sarcoma, chondrosarcoma, epithelioid leiomyosarcoma, malignant fibrous histiocytoma, and leiomyoma. Only three patients, one each with liposarcoma, leiomyosarcoma, and synovial sarcoma, manifested MSI, whereas, osteosarcoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, and synovial sarcoma manifested LOH, with an incidence of 43%, 14%, 86%, 20%, and 75%, respectively. Interestingly, three patients showed unusual patterns of LOH, probably due to intratumoral heterogeneity. Kaplan-Meier analysis revealed that LOH on 11p was predictive of poor prognosis in osteosarcoma. The low incidence of MSI indicates that MSI is not necessary for neoplastic transformation in sarcomas. However, the very high incidence of LOH in leiomyosarcoma indicates that microsatellite analysis may serve for the differential diagnosis of leiomyosarcoma versus leiomyoma. Microsatellite analysis may also predict prognosis in osteosarcoma.

Adolescent↗
PubMed1994

Cytogenetic intratumor heterogeneity in soft tissue tumors.

Multiple (two to seven) samples, obtained from the same surgical specimen or at different occasions, were analyzed in 54 benign and malignant soft tissue tumors, to investigate cytogenetic clonal evolution. In 28 tumors only normal karyotypes were found. Ten tumors had abnormal karyotypes, but were noninformative, most often due to a high level of karyotypic complexity or great cell-to-cell variation. Sixteen tumors were informative: four (leiomyosarcoma, liposarcoma, malignant Schwannoma, and a benign mesenchymal tumor, probably leiomyoma) had identical karyotypes in different samples, whereas the remaining 12 tumors (seven malignant fibrous histiocytomas [MFH], two leiomyosarcomas, two liposarcomas, and one synovial sarcoma) displayed intersample heterogeneity. Also, intrasample heterogeneity was detected; more than one clone was found in 21 of 73 samples with aberrations from 26 tumors. The different clones were related in all cases except two. In seven cases, samples from different occasions were studied, and clonal evolution could be evidenced in five of them, whereas in two cases the karyotypes remained unchanged. The results indicate that the acquisition of ring chromosomes is an early event in the development of MFH and possibly also pleomorphic liposarcoma. The findings, together with previous data, also indicate that rearrangements of 19p13 are late events in the progression of pleomorphic sarcomas. The overall conclusion from this study is that cytogenetic heterogeneity is common in soft tissue tumors, and that this might influence the evaluation of cytogenetic and molecular genetic findings.

Adult↗
PubMed1999

Development of a monoclonal antibody to the aP2 protein to identify adipocyte precursors in tumours of adipose differentiation.

aP2 gene product (aP2 protein) expression has been shown to be a useful diagnostic marker for identification of lipoblasts and fetal fat cells in soft tissue tumours. A monoclonal antibody was developed by a mouse spleen cell-myeloma hybridoma technique to an 18 amino acid segment of the aP2 protein and was used to investigate the immunohistochemical expression of this protein in benign and malignant tumours of adipocytic differentiation and a wide variety of other soft tissue tumours. We found that aP2 protein was expressed by lipoblasts in liposarcomas and lipoblastomas and by brown fat cells in hibernomas and normal periadrenal fat. Other benign adipose tissue tumours and benign and malignant soft tissue tumours were distinguished from liposarcoma by absence of staining for aP2 protein. Immunohistochemical identification of the aP2 protein is likely to prove a useful means of distinguishing liposarcoma from other malignant mesenchymal and epithelial neoplasms, some of which contain cells that morphologically resemble lipoblasts.

Adipocytes↗
PubMed2002

Validity and reproducibility of histologic diagnosis and grading for adult soft-tissue sarcomas.

Soft-tissue sarcomas in adults show great variations in histologic type and grade. A valid and reproducible prognostication system is needed to select patients with soft-tissue sarcomas who could benefit from adjuvant chemotherapy. This study was conducted to assess the validity and reproducibility of diagnosis of the histologic type, MIB-1 grade, and mitosis grade, as well as of the 3 components of these grading systems. MIB-1 grade is a recently proposed grading system for predicting the prognosis of patients with adult soft-tissue sarcomas on the basis of 3 criteria (tumor differentiation, necrosis, and MIB-1 score) and replaces the mitotic count in the French system with MIB-1 immunohistochemical staining. Four surgical pathologists from 4 institutions who had experience in diagnostic soft-tissue tumor pathology reviewed 130 cases of soft-tissue sarcoma and independently determined histologic type and grade. The validity of histologic diagnosis was measured by sensitivity and specificity, and that of grading was measured by kappa statistics and percentage agreement with the diagnosis of the expert panel at the National Cancer Center, which was defined as a gold standard. Interobserver reproducibility was measured by kappa and by percentage agreement between the diagnoses of the 4 pathologists. The validity of the diagnosis of histologic type was high for synovial sarcoma, small round-cell sarcoma, and liposarcoma (sensitivity 89% to 100%; specificity, 98% to 100%) but low for malignant fibrous histiocytoma (MFH) and spindle-cell sarcoma (73% to 75%; 93% to 95%). For the grading, the validity of the MIB-1 grade was substantial (kappa = 0.68; agreement, 79%) and higher than that of the mitosis grade (0.54; 69%). The most valid component was tumor differentiation (kappa = 0.79), followed by tumor necrosis (0.66), MIB-1 score (0.59), and mitotic score (0.37). Interobserver reproducibility of histologic diagnosis was high for small round-cell sarcoma, synovial sarcoma, and liposarcoma (kappa = 0.92, 0.90, 0.87; percentage agreement = 99%, 97%, 96%, respectively); for grading, reproducibility was highest for tumor differentiation (0.78; 87%) and second highest for MIB-1 grade (0.68; 79%). We conclude that diagnosis of the type of soft-tissue sarcoma for synovial sarcoma, small round-cell sarcoma, and liposarcoma and the MIB-1 grading system based on tumor differentiation are highly valid and reproducible among Japanese pathologists who are familiar with the grading system, whereas re-evaluation of histologic criteria is essential for other histologic types such as MFH and spindle-cell sarcoma.

Antigens, Nuclear↗
PubMed1996

Reverse transcriptase-polymerase chain reaction amplification of MDR1 gene expression in adult soft tissue sarcomas.

Expression of the multidrug resistance gene MDR1 is reported to be an important determinant of the response to chemotherapy and survival in some cancers. We compared three methods for determining the intrinsic MDR1 expression in soft tissue sarcomas. We studied MDR1 gene expression in 39 samples from 33 cases of soft tissue sarcomas comprising 11 liposarcomas, nine malignant fibrous histiocytomas, six leiomyosarcomas, four malignant schwannomas, three fibrosarcomas, three synovial sarcomas, and three epithelioid sarcomas, and seven cases of benign soft tissue tumors in adult patients. To detect MDR1 mRNA, reverse transcriptase-polymerase chain reaction (RT-PCR) was performed in all samples. Furthermore, RNA dot-blot analysis with digoxigenin-labeled RNA probe and immunohistochemistry with JSB-1 and C-219 antibodies for P-glycoprotein were employed in 34 and 37 samples in soft tissue sarcomas, respectively. We compared these three detection techniques. Of the 39 specimens, 18 (46%) showed MDR1 PCR products. Liposarcomas (six of 11), malignant fibrous histiocytomas (six of nine), leiomyosarcomas (four of six), fibrosarcomas (two of three) revealed high or intermediate MDR1 expression at high frequency. No MDR1 expression was detectable in malignant schwannomas, synovial sarcomas, or epithelioid sarcomas. Of seven benign soft tissue tumors, one ganglioneuroma and one lipomatosis showed low levels of MDR1 expression. By RNA dot-blot analysis, MDR1 transcripts were detectable in 12 of 34 specimens (35%). Four samples were negative by dot blot despite positivity with RT-PCR. Concordance between MDR1 expression by RNA level with RT-PCR and dot blot and at the protein level with immunohistochemistry using C-219 was found in 16 (47%) of the 34 comparable specimens. Eight samples showed positive immunoreactivity for C-219 despite negative results in RT-PCR and dot-blot analysis. The intrinsic MDR1 expression in soft tissue sarcoma seemed to depend on certain tumor types, such as liposarcoma, malignant fibrous histiocytoma, leiomyosarcoma, and fibrosarcoma. For the evaluation of MDR1 expression, RT-PCR is useful because of its relative simplicity and sensitivity. However, the clinical significance of such low levels of MDR1 expression detected only by RT-PCR must be discussed within systematically treated patient groups.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

A unique dedifferentiated tumor of the retroperitoneum.

BACKGROUND: Dedifferentiated liposarcomas represent heterogeneous tumors with lipomatous and nonlipomatous elements starkly juxtaposed. It is thought that the high grade nonlipomatous elements of the tumor portend a worse prognosis. CASE PRESENTATION: A 19.8 kg heterogeneous retroperitoneal tumor was successfully and completely resected. Because of its extent, no additional treatment modalities were practicable. The tumor soon recurred. The recurrent tumor differed from the primary tumor in that it was more homogeneous, consisting mainly of nonlipogenic, calcific tissue. CONCLUSIONS: Dedifferentiated liposarcomas are known to have a very high recurrence rate. The biological behavior of dedifferentiated liposarcomas is likely dictated by the most aggressive element of these heterogeneous tumors.

Journal Article↗
PubMed2006

The tip of the iceberg: a giant pelvic atypical lipoma presenting as a sciatic hernia.

BACKGROUND: This case report highlights two unusual surgical phenomena: lipoma-like well-differentiated liposarcomas and sciatic hernias. It illustrates the need to be aware that hernias may not always simply contain intra-abdominal viscera. CASE PRESENTATION: A 36 year old woman presented with an expanding, yet reducible, right gluteal mass, indicative of a sciatic hernia. However, magnetic resonance imaging demonstrated a large intra- and extra-pelvic fatty mass traversing the greater sciatic foramen. The tumour was surgically removed through an abdomino-perineal approach. Subsequent pathological examination revealed an atypical lipomatous tumour (synonym: lipoma-like well-differentiated liposarcoma). The patient remains free from recurrence two years following her surgery. CONCLUSION: The presence of a gluteal mass should always suggest the possibility of a sciatic hernia. However, in this case, the hernia consisted of an atypical lipoma spanning the greater sciatic foramen. Although lipoma-like well-differentiated liposarcomas have only a low potential for recurrence, the variable nature of fatty tumours demands that patients require regular clinical and radiological review.

Journal Article↗