TLS-CHOP target gene DOL54 expression in liposarcomas and malignant fibrous histiocytomas

Downstream of the gene for the liposarcoma-associated fusion oncoprotein 54 (DOL54) is a target gene of the myxoid liposarcoma and round cell liposarcoma (M-LPS/RC-LPS) oncogene, TLS/FUS-CHOP. The DOL54 gene product is closely associated with adipogenic differentiation. DOL54 overexpression resulted in tumorigenicity when Chinese Hamster Ovary (CHO) cells were injected subcutaneously into nude mice. The biological significance of DOL54 expression for human malignant soft tissue tumors, however, has not yet been investigated. We examined TLS-CHOP and DOL54 expression in M-LPS/RC-LPS, well-differentiated liposarcoma and malignant fibrous histiocytoma (MFH), a tumor whose cellular origin has not been determined. We observed DOL54 expression in 50% of M-LPS/RC-LPS cases (in which TLS-CHOP was also expressed) and 33% of MFH cases, suggesting that a portion of MFH lesions may either derive from adipocytic precursor cells or have the potential to undergo adipogenic differentiation. In this manner, M-LPS/RC-LPS and MFH lesions may share tumorigenic characteristics, resulting from the unscheduled expression of DOL54.     

Establishment and characterization of a novel dedifferentiated liposarcoma cell line, NDDLS-1

We established a dedifferentiated liposarcoma cell line (NDDLS-1) that produces interleukin-6 (IL-6) and granulocyte-colony stimulating factor (G-CSF). The parental tumor showed high leukemoid reactions. The NDDLS-1 cell line was established from a pleural effusion associated with a lung metastasis. Pleomorphic tumor cells arranged in a haphazard growth pattern were seen in xenograft tumors. Numerous inflammatory cells including neutrophils or eosinophils were present throughout the tumor cells. This finding resembled the dedifferentiated area of the parental tumor. The mice bearing NDDLS-1 showed marked leukocytosis. In addition, the NDDLS-1 cells expressed IL-6 and G-CSF at both the mRNA and protein levels, while the NDDLS-1 cells produced near normal levels of tumor necrosis factor alpha (TNF-α). In the cytogenetic analysis, both the parental tumor and the NDDLS-1 cells showed a ring or giant marker chromosomes. The NDDLS-1 cell line demonstrated the amplification and expression of both MDM2 and CDK4 by fluorescence in situ hybridization and immunohistochemical analysis. The NDDLS-1 cell line is consistent with the parental dedifferentiated liposarcoma, and it should therefore be useful for further investigations of human dedifferentiated liposarcomas.     

Prognostic significance of the MDM2/HMGA2 ratio and histological tumor grade in dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a relatively common soft tissue sarcoma that results from the progression of well‐differentiated liposarcoma (WDLPS). This study aimed to investigate the progression process and to clarify the pathological and genetic factors related to poor prognosis in DDLPS. In 32 DDLPS cases and five WDLPS cases, genetic factors were analyzed by custom comparative genomic hybridization (CGH) array, which was designed to densely cover gene regions known to be frequently amplified in WD/DDLPS. The analyses comparing primary and metastatic lesions and those comparing histologically different areas in the same tumor revealed intra‐tumoral genetic heterogeneity and progression. According to a prognostic analysis comparing the good‐prognosis and the poor‐prognosis groups, we selected MDM2 and HMGA2 as candidate genes associated with poor and good prognosis, respectively. The ratios of the amplification or gain levels of MDM2 and HMGA2 expressed in log ratios (log[MDM2/HMGA2] = log[MDM2]‐log[HMGA2]) were significantly associated with prognosis. An amplification or gain level of MDM2 that was more than twice that of HMGA2 (MDM2/HMGA2 > 2, log[MDM2/HMGA2] > 1) was strongly related to poor OS (P < .001) and poor distant metastasis‐free survival (DMFS) (P < .001). In the pathological analysis of 44 cases of DDLPS, histological tumor grade, cellular atypia, and MDM2 immunoreactivity were related to overall survival (OS), while HMGA2 immunoreactivity tended to be associated with OS. Cellular atypia was also associated with DMFS. In conclusion, histological grade and MDM2 expression were determined to be prognostically important, and the MDM2/HMGA2 amplification or gain ratio was found to have significant prognostic value by the custom CGH array analysis.     

Evaluation of MDM2 and CDK4 amplification by real-time PCR on paraffin wax-embedded material: a potential tool for the diagnosis of atypical lipomatous tumours/well-differentiated liposarcomas

Atypical lipomatous tumours/well-differentiated liposarcomas and dedifferentiated liposarcomas are characterized by 12q13-15 region amplification. In contrast, this molecular event has not been reported in benign lipomas. Within the 12q13-15 chromosomal region, the MDM2, SAS, HMGA2, and CDK4 genes are the most frequent targets of amplification. A series of lipomas (36 cases) and liposarcomas (48 cases) was analysed for MDM2 and CDK4 gene amplification by real-time PCR. MDM2 and CDK4 gene amplification was detected in 2.8% and 5.6% of lipomas and 98.2% and 82.4% of liposarcomas, respectively. Moreover, co-amplification of the two genes as well as a higher-level amplification was observed more frequently in dedifferentiated liposarcomas than in atypical lipomatous tumours/well-differentiated liposarcomas. Real-time PCR proved to be a fast and reliable method to characterize lipomas and liposarcomas by quantification of MDM2 and CDK4 gene amplification. It is applicable to paraffin wax-embedded tissues and could be useful when histological diagnosis is difficult.     

Inflammatory malignant fibrous histiocytoma of kidney: a case report

Among the renal sarcomas, inflammatory malignant fibrous histiocytoma (MFH) is an extremely rare presentation. A 45-year-old woman presented with acute retention urine following an episode of gross hematuria. Computerized tomography showed a solid mass at the lower pole of the left kidney. The patient underwent left nephrectomy. Histologically and immunohistochemically, the tumor was diagnosed as an inflammatory subtype of MFH. Histological appearances of inflammatory MFH vary widely and frequently overlap with benign reactive conditions such as Xanthogranulomatous pyelonephritis (XGPN) and malignant lesions, e.g. malignant lymphoma and, less frequently, a sarcomatoid variant of renal cell carcinoma. It is important, though difficult, to differentiate inflammatory MFH from these lesions. Careful morphological examination and immunohistochemical findings of the lesion are of great value, in particular in excluding it from its mimics. We discuss the pathological features and challenges involved in differentiating inflammatory MFH from its masquerader.     

Well‐differentiated and dedifferentiated liposarcomas with prominent myxoid stroma: analysis of 56 cases

Aims: Occasional cases of well‐differentiated and dedifferentiated liposarcoma (LPS) contain myxoid stroma, leading to confusion with other sarcomas. The aim of this study was to analyse the clinicopathological and genetic features of well‐differentiated/dedifferentiated LPS with prominent myxoid stroma. Methods and results: Fifty‐six cases of LPS (22 well‐differentiated; 34 dedifferentiated) with prominent myxoid stroma were evaluated. Most arose in the retroperitoneum, abdominal cavity, or spermatic cord. The mean size was 170 mm. Myxoid LPS‐like plexiform vessels were conspicuous in 11 cases of well‐differentiated LPS. In 22 cases of dedifferentiated LPS, myxofibrosarcoma‐like curvilinear vessels were prominent. In other cases, the myxoid component had variably bland or pleomorphic morphology. By immunohistochemistry, staining for MDM2 was positive in 95% of cases, and CDK4 in 78%. Cytogenetics in 13 cases showed ring and giant marker chromosomes. Fluorescence in‐situ hybridization showed amplification of 12q13–15 in six cases evaluated. Of 30 patients with follow‐up, all but one had local recurrences (up to four), but only one has so far had distant metastases. Conclusions: Well‐differentiated/dedifferentiated LPS with prominent myxoid stroma can closely resemble other sarcoma types, especially myxoid LPS and myxofibrosarcoma. The clinical presentation (large retroperitoneal or abdominal tumour) is a clue to the correct diagnosis; the degree of nuclear atypia helps to exclude myxoid LPS. Immunohistochemistry for MDM2 and CDK4 and genetic analysis can be useful to confirm the diagnosis.     

Primary hepatic malignant fibrous histiocytoma: Report of a case and review of the literature

Malignant fibrous histiocytoma (MFH) is a common sarcoma of adulthood, frequently arising in the extremities, but also in the abdomen and the retroperitoneum. Primary MFH of the liver, however, remains extremely rare and is one of the least diagnosed primary hepatic sarcoma. Another case of primary MFH of the liver is reported. The patient presented with a 12 cm mass involving the right and left lobes of the liver. The histopathologic examination revealed a typical MFH swirling (storiform) pattern composed of atypical spindle and giant cells. The radiologic, histologic, and clinical behavior of this rare neoplasm are reviewed.     

p53 gene mutation and MDM2 overexpression in a case of primary malignant fibrous histiocytoma of the jejunum

Primary malignant fibrous histiocytoma of the gastrointestinal tract is extremely rare. To date, only 10 cases of primary malignant fibrous histiocytoma arising in the small intestine have been reported in the English literature. We describe here the genetic alterations and morphologic features of a primary malignant fibrous histiocytoma arising in the jejunum. Immunohistochemically, the tumor cells expressed vimentin, CD68 and alpha-1-antitrypsin, but were negative for other markers. Ultrastructurally, they showed features of fibroblasts and histiocytes. Immunohistochemical overexpression of p53 and MDM2 was observed. Mutation analysis of the p53 gene detected a missense mutation in codon 158 of exon 5. Our results suggest that p53 gene mutations and MDM2 overexpression may play an important role in the tumorigenesis. To our knowledge, the present report is the first genetic study of this rare lesion.     

MDM2 and CDK4 gene amplification in Ewing's sarcoma

Amplification of the MDM2 gene, which maps to chromosome band 12q13 and encodes a p53-binding protein, may result in functional inactivation of p53 and has been observed in various bone and soft tissue sarcomas. Published studies have included few cases of Ewing's sarcoma (ES) or peripheral neuroectodermal tumour (PNET), a tumour group in which alterations of the p53 pathway have so far not been extensively studied. We examined two ES cell lines, RD-ES and SK-ES-1, and 30 specimens from 27 patients (24 ES, 6 PNET; 19 primary, 4 local recurrence, 7 metastasis) for MDM2 gene amplification by Southern blot analysis. All 30 clinical specimens had been confirmed to contain sufficient ES/PNET DNA by the demonstration of a rearrangement of the t(11;22)-associated EWS gene using an EWS cDNA probe on the same blots. MDM2 gene amplification was detected in 3 of 30 specimens (10 per cent), including two ES and one PNET, but in neither of the cell lines. The three cases with amplification were morphologically typical primary tumours. Two of the three cases also showed co-amplification of the CDK4 gene, which endoces a cyclin-dependent kinase and also maps to band 12q13. Clinically, all three cases had metastatic disease at diagnosis, compared with only 1 of 15 MDM2-negative cases where the primary tumour was studied. The difference was statistically significant (P=0.005), suggesting an association of MDM2 amplification with advanced stage. Further accural and multivariate analysis of ES/PNET cases with MDM2 gene amplification will be necessary to confirm the clinical significance of these findings. The results suggest that the prevalence of MDM2 gene amplification in ES/PNET is comparable to other sarcomas, and implicate dysfunction of the p53 pathway in a subset of ES/PNET. The biological significance of CDK4 co-amplification remains to be determined.     

Inflammatory leiomyosarcoma: a morphological subgroup within the heterogeneous family of so-called inflammatory malignant fibrous histiocytoma

Twelve cases of inflammatory leiomyosarcoma are presented. These tumours arose in the deep soft tissues of the trunk and proximal limbs. The age of the patients ranged from 13–53 years (median 36 years); there was an approximately equal sex ratio. Follow-up data was available for nine patients (mean duration 3.3 years); local recurrence occurred in three and lung metastases in one. Lesions were spindle cell neoplasms with fascicular areas which occupied between 5% and 80% of the tumour. Areas with a distinct storiform pattern were also seen in 10 cases. A prominent inflammatory cell component was evident in all tumours, often masking the neoplastic spindle cells. Histiocytes were identified in all cases, with aggregates of xanthoma cells seen in eight tumours. In 10 cases there was also a dense lymphoid infiltrate and in two a marked polymorphonuclear leukocyte infiltrate was evident. Immunohistochemistry showed in all tumours that the spindle cells stained positively for myogenic markers (8 of 12 positive for desmin, 10 of 12 for alpha smooth muscle actin and 11 of 12 for HHF-35). CD68 was expressed by the histiocytic infiltrates. Many of these tumours were diagnosed initially as inflammatory malignant fibrous histiocytoma. We provide evidence that at least one subset of neoplasms, which would have been formerly classified under this rubric, in fact show smooth muscle differentiaton. Further studies are required to investigate the possibility that other tumour types or lines of differentiation may be present within the category of so-called inflammatory malignant fibrous histiocytoma.     

MDM2 and CDK4 expression in carcinosarcoma of the esophagus: comparison with squamous cell carcinoma and review of the literature

Certain tumors of the esophagus that display both sarcomatous and carcinomatous features have long been recognized. The nomenclature, classification, and histogenesis remain controversial and the microscopic differential diagnosis from other esophageal malignancies can be challenging, particularly in small biopsies. In this paper, we review the literature of carcinosarcoma and present two cases of esophageal carcinosarcoma, describing their salient histologic, immunohistochemical, and ultrastructural features. Also, we assess the expression of MDM2 and CDK4 in the carcinomatous and sarcomatous compartments of our cases and we compare them with the expression of these oncogenes in selected cases of esophageal squamous cell carcinoma with prominent stromal reaction. In both of our cases, identification of some epithelial ultrastructural and immunohistochemical features in cells of otherwise sarcomatous phenotype lends support to the common epithelial origin of these neoplasms. Moreover, positive staining for MDM2 and CDK4 in our cases with equally strong reactions in both carcinomatous and sarcomatous elements provides evidence of a role for these molecules in the pathogenesis of carcinosarcoma. In contrast, in cases of squamous cell carcinoma with prominent stromal reaction only the epithelial cells stained strongly for MDM2 and CDK4. These differences in the MDM2 and CDK4 immunohistochemical profile between carcinosarcomas and carcinomas of the esophagus may assist in their differential diagnosis.     

The value of MDM2 and CDK4 amplification levels using real-time polymerase chain reaction for the differential diagnosis of liposarcomas and their histologic mimickers

Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL) are reported to have murine double-minute type 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) amplification as a characteristic genetic alteration. To evaluate the diagnostic utility of this gene abnormality, we analyzed 19 liposarcomas, 21 malignant fibrous histiocytomas, 3 leiomyosarcomas, 5 malignant peripheral nerve sheath tumors, 23 lipomas, and 28 nonneoplastic fat tissues using real-time polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH). In real-time PCR, all ALT/WDLs and DDLs had both MDM2 and CDK4 amplifications. The amplification levels in ALT/WDLs and DDLs were significantly higher than those in the other sarcomas, lipomas, and nonneoplastic fat tissues (P < .05); however, those in the other sarcomas and lipomas were not significantly higher than those in nonneoplastic tissues. In FISH, all ALT/WDLs and DDLs had both MDM2 and CDK4 amplifications, and all of the myxoid/round cell liposarcomas, leiomyosarcomas, malignant peripheral nerve sheath tumors, and all but one of the malignant fibrous histiocytomas did not have the amplifications. In this study, MDM2 and CDK4 amplifications were confirmed in ALT/WDLs and DDLs, and the amplification levels were significantly higher than those in the other tumors. An analysis of MDM2 and CDK4 amplification using real-time PCR, as well as FISH, is useful for the differential diagnosis of liposarcomas and their histologic mimickers.     

Malignant fibrous histiocytoma of the cecum: Report of a case and review of the literature

Malignant fibrous histlocytoma (MFH) of the gastrointestinal tract is extremely rare. Here we report a case of MFH of the cecum and mlew other cases of large bowel MFH in the Ilteratura. A 64-year-old man had a large tumor mass in the cecum associated with multiple small peritoneal implants. Hirtologically, most of the lesion showed Inflammatory pseudo tumor-like appearance; that is, a mixed proliferation of fibroblasts and myofibroblasts loosely arranged in sweeping fascicules or whorled structures and an admixture of chronlc Inflammatory cell Inflltrate. The myofibroblastic nature of the spindle-shaped cells was conflrmed by their Immunohistochsmical and ultrastructural findings. In addition, there was atypical histlocytic cells Infiltrate In some areas and marked lymphatlc involvement and lymph node metastasis by such histiocytic cells. These features were Interpreted as MFH, although It had to be distinguished from inflammatory fibrosarcoma and leiomyosarcoma. The differential diagnosis is discussed here.     

Ultrasound‐guided fine‐needle aspiration of a posterior neck dedifferentiated liposarcoma with MDM2 fluorescence in situ hybridization performed on a Pap‐stained smear

Head and neck liposarcomas, while rare, tend to be subcutaneous and well‐differentiated. Dedifferentiated liposarcomas of the head and neck are exceedingly rare in the literature. We present a case of a dedifferentiated liposarcoma arising in the soft tissue of the posterior neck of an 86‐year‐old man and diagnosed by fine‐needle aspiration. Aspirate smears showed a dual population of atypical lipomatous and spindled cells. MDM2 (murine double minute 2) amplification was demonstrated on a Pap‐stained smear using fluorescence in situ hybridization (FISH). To the best of our knowledge, this is the first report of MDM2 FISH amplification in a liposarcoma performed on an aspirate smear. Diagn. Cytopathol. 2015;43:320–324. © 2014 Wiley Periodicals, Inc.     

Dedifferentiated liposarcoma of the spermatic cord with a hemangioendothelioma-like component: A case report and review of the literature

Atypical lipomatous tumor or well-differentiated liposarcoma/dedifferentiated liposarcoma (DDLPS) is the most frequent subtype of malignant adipocytic tumor. This tumor typically presents in late adult life, most commonly in the retroperitoneum, extremities, or spermatic cord. It has been reported that the dedifferentiated component consists mainly of high-grade sarcoma, including undifferentiated pleomorphic sarcoma, fibrosarcoma, and myxofibrosarcoma, and it has been recently reported that the dedifferentiated component can be also made up of a low-grade sarcomatous component. Therefore, the dedifferentiated areas exhibit a wide morphological spectrum that commonly includes fibroblastic/myofibroblastic and fibrohistiocytic tumors but very rarely includes vascular tumors. We present here the first reported case of DDLPS with a hemangioendothelioma-like component in the spermatic cord.     

Comparative fine-needle aspiration and pathologic study of malignant fibrous histiocytoma: cytodiagnostic features of 95 tumors in 71 patients

To determine diagnostic cytomorphologic features of malignant fibrous histiocytoma (MFH) on fine-needle aspiration (FNA) materials, we reviewed the cytologic material and corresponding histologic slides of 95 tumors in 71 patients. Forty-four (46%) tumors were primary, 38 (40%) were recurrent, and 13 (14%) were metastatic. Histological variants of MFH were as follows: 52 (54.7%, 43 patients) were of the storiform/pleomorphic, seven (7.4%, five patients) were giant cells, four (4.2%, four patients) were inflammatory, and 31 (33.7%, 19 patients) were myxoid type. Review of original cytology reports showed that only 23 (24.2%) tumors were diagnosed as MFH and 68 (71.6%) as other types of malignancies. Four (4.2%) cases were reported as unsatisfactory/suspicious. Our findings showed that spindle-shaped, round, giant cells, osteoclastic-like giant, and inflammatory cells were the most consistent features that allow identification of the storiform/pleomorphic, giant cell, and inflammatory variants of MFH. The myxoid tumors had marked myxoid background matrix with spindle-shaped cells and, less frequently, round and giant cells. Pleomorphic leiomyosarcoma and dedifferentiated liposarcoma should be considered in the differential diagnosis of stroriphorm/pleomorphic, giant cells, and inflammatory variants of MFH. However, myxoid MFH may resemble their leiomyosarcoma and liposarcoma counterparts.     

Mixed-type liposarcoma: clinicopathological, immunohistochemical, and molecular analysis of a case arising in deep soft tissues of the lower extremity

A rare case of mixed-type liposarcoma arising in deep soft tissue of the right thigh of a 45-year-old female patient is reported. The neoplasm was completely excised and was composed of an irregular admixture of areas of atypical lipomatous tumor/well-differentiated liposarcoma of the lipoma-like subtype with areas of myxoid/round cell liposarcoma. An amplification of the MDM2 and CDK4 genes respectively in the atypical lipomatous tumor/well-differentiated liposarcoma areas was detected by fluorescence in situ hybridization (FISH) analysis, and translocations of the CHOP and FUS genes were detected by FISH analysis in the myxoid/round cell liposarcoma areas.     

Molecular abnormalities in liposarcoma: role of MDM2 and CDK4-containing amplicons at 12q13–22

It has recently been shown that mdm2 overexpression with stabilization of p53 represents a characteristic of retroperitoneal well-differentiated-dedifferentiated, here renamed evolved (WD-E), liposarcomas at the immunocytochemical, molecular, and cytogenetic level. This make-up appears to be confined to half the cases in non-retroperitoneal well-differentiated liposarcomas. Since in different tumours MDM2 amplification involves amplicons encompassing flanking genes, such as CDK4, the possibility was investigated that in these tumours, CDK4 could act as an alternative or additional gene involved in the transformation mechanism. Forty-one retroperitoneal (R)/non-retroperitoneal (NR) well-differentiated-dedifferentiated (WD-DD) and 33 myxoid/round cell liposarcomas were reanalysed by immunocytochemical, molecular (nine cases) and fluorescence in situ hybridization (FISH) (one case) techniques. The results showed that all but one R WD-E cases carried the mdm2+, p53+, cdk4+ immunophenotype. In NR-WD liposarcomas, this immunophenotype was shared in five cases and the remainder showed mdm2+, p53−, cdk4+ in four and mdm2−, p53−, cdk4+ in one case, showing ring chromosomes by FISH analysis. TP53 mutations are confirmed to be closely correlated with NR-DD liposarcomas and no CDK4 involvement was found in the myxoid/round cell liposarcoma group. As well as confirming the synergistic effect of MDM2 and CDK4, these results are consistent with the concept that amplicon(s) excluding MDM2 may contribute to transformation and support a role of CDK4 in opposing p53 function, particularly in NR WD liposarcoma. © 1998 John Wiley & Sons, Ltd.