Endometrial metaplasia: correlation of histological and cytological specimens obtained from 103 cases undergoing hysterectomy for endometrial carcinoma.

OBJECTIVE: To assess the frequency of endometrial metaplasia in histological and cytological specimens from the same cases, and to determine the relationship between various types of metaplasia and clinicopathological findings. METHODS: We reviewed 103 histological specimens diagnosed as endometrioid adenocarcinoma, in which endometrial smears had been obtained before surgery. We examined the correlation between the frequency of endometrial metaplasia occurring in association with carcinoma in both histological and cytological specimens. The categories of metaplasia were eosinophilic metaplasia, squamous metaplasia, mucinous metaplasia, ciliated cell metaplasia and others. We compared the incidence of endometrial metaplasia with the clinicopathological findings for each case. RESULTS: Endometrial metaplasia was recognized in 90 (87.4%) of the histological and 80 (77.7%) of the cytological specimens of 103 specimens, with the respective frequency of subtypes as follows: eosinophilic metaplasia (36.0% and 43.7%), squamous metaplasia (70.9% and 68.0%), mucinous metaplasia (38.8% and 19.4%), ciliated cell metaplasia (22.3% and 2.9%) and others (11.7% and 0%). Mixed subtypes were seen in 58.3% and 41.7% of histological and cytological specimens, respectively. In histology, mucinous metaplasia was significantly more frequent in G1-G2 than G3 carcinomas (P = 0.0089). Ciliated cell metaplasia was significantly related to endometrial hyperplasia (P = 0.0068). In cytology, eosinophilic and mucinous metaplasia were significantly associated with G1-G2 cases (P = 0.0061 and P = 0.0385). CONCLUSIONS: Endometrial metaplasia was seen in 87.4% of the histological and 77.7% of the cytological specimens. Where routine endometrial cytopathology is practiced, it is important to understand the detailed histological and cytological features of these changes.

Low-grade fibromyxoid sarcoma versus low-grade myxofibrosarcoma in the extremities and trunk. A comparison of clinicopathological and immunohistochemical features.

AIMS: Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma and has been reported to have metastatic potential despite its low-grade histological findings. Low-grade myxofibrosarcoma (MFS) is an important differential diagnosis of LGMFS, because it shows different biological behaviour. Of 75 MFSs in the extremities and trunk, we defined 22 grade 1 tumours as low-grade MFS according to the French Federation of Cancer Centres grading system and compared the clinicopathological factors and immunohistochemical expression of cell cycle regulators with those of 11 LGFMSs. METHODS AND RESULTS: The two entities could be distinguished on histological grounds. Low-grade MFS was characterized by the presence of prominent elongated, curvilinear capillaries and pseudolipoblasts, accompanied by an abundant myxoid matrix. It had no extensive solid areas. LGFMS was composed of bland spindle cells arranged in a whorled pattern with alternating myxoid and fibrous stroma. Curvilinear capillaries were not prominent and cytological atypia was absent. No tumour necrosis was observed in any of the 11 LGFMSs, whereas only one case showed tumour necrosis in less than 50% of the tumour in 22 low-grade MFSs. The patients with low-grade MFS were significantly older than those with LGFMS (low-grade MFS average, 60.1 years; LGFMS average, 31.5 years; P < 0.0001) and low-grade MFS occurred more frequently in a superficial location (low-grade MFS 14/20; LGFMS 2/11; P = 0.0077). As for cell cycle regulator expression, the MIB-1 labelling index (LI) (14.76 on average) and cyclin E LI (11.55 on average) in low-grade MFS were significantly higher than those (MIB-1 LI, 4.68 on average; cyclin E LI, 3.38 on average) of LGFMS, while p21 LI (25.53 on average) and p27 LI (42.68 on average) in low-grade MFS were significantly lower than those (p21 LI, 42.74 on average; p27 LI, 57.28 on average) of LGFMS. CONCLUSIONS: We conclude that low-grade MFS and LGFMS are distinctly different clinicopathological entities and the assessment of the immunohistochemical expression of MIB-1, cyclin E, p21 and p27 as well as conventional clinicopathological features may be helpful to distinguish low-grade MFS from LGFMS.

Characterisation of TGF-beta2 signalling and function in a human lens cell line.

There is increasing evidence implicating Transforming growth factor beta (TGF-beta) in pathological states of the lens. However, the underlying signalling mechanisms in human cells have not been fully examined. We have therefore investigated in a human lens cell line, FHL 124, the signalling characteristics of TGF-beta and Smad proteins. Moreover, we have tested the effectiveness of a fully human monoclonal anti-TGF-beta2 antibody, CAT-152, in suppressing TGF-beta2 induced changes in a number of conditions. FHL 124 cells were routinely cultured in Eagle's minimum essential medium (EMEM) supplemented with 10% FCS. Characterisation of the cell line was determined using Affymetrix gene microarrays and compared to native human lens epithelium. Cells were serum starved for 24 hr prior to exposure to TGF-beta2 in the presence and absence of CAT-152. Non-stimulated cells served as controls. Smad 4 localisation was observed by immunocytochemistry. To study Smad-dependent transcriptional activity, cells were transfected with SBE4-luc, an artificial smad-specific reporter, using Fugene-6. Transcriptional activity was determined by luciferase activity. Gene expression was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR). Proliferation was determined by 3H-thymidine DNA incorporation. Growth and contraction were assessed using a scratch and patch assay. Affymettrix gene microarrays identified 99.5% homology between FHL 124 cells and the native lens epithelium with respect to expression pattern of the 22,270 genes on the chip. Moreover, FHL 124 cells expressed phenotypic markers, alphaA-crystallin and pax6 along with lens epithelial cell specific marker FoxE3. Immunocytochemical studies revealed the presence of Smad 4 which following TGF-beta2 exposure accumulated in the cell nucleus. Furthermore, Smad-dependent transcriptional activity was also stimulated. TGF-beta2 enhanced the expression of mRNA levels of alpha smooth muscle actin (alphaSMA) and connective tissue growth factor (CTGF). Exposure to TGF-beta2 resulted in a relatively small inhibition of 3H-thymidine incorporation of FHL 124 cells. However, a more marked contractile effect was also observed. In serum-supplemented medium, growth rates and TGF-beta induced contraction were enhanced. Treatment with 0.1-10 microg ml(-1) CAT-152 dose-dependently inhibited 10 ng ml(-1) TGF-beta2 induced effects in the presence and absence of serum. Exposure of FHL 124 cells to TGF-beta therefore induces Smad translocation, transcription, expression of transdifferentiation markers and induces marked contraction. Treatment with CAT-152 can effectively inhibit these responses. TGF-beta2 induced changes can also persist long after the period of exposure and when in the presence of serum TGF-beta induced contraction is enhanced. The work presented therefore demonstrates a platform technology to study TGF-beta2 signalling in human lens epithelial cells and provides evidence to show TGF-beta2 can be a potent factor in the development of posterior capsule opacification following cataract surgery.

p53 Mutation and MDM2 amplification in inflammatory myofibroblastic tumours.

AIMS: The pathogenic mechanism and predictive indicators of biological behaviour of inflammatory myofibroblastic tumour are poorly understood. We investigated molecular abnormalities of p53 and MDM2 in order to assess whether these play an important role in pathogenesis, and whether they also contribute to clinicopathological aggressive phenotype in inflammatory myofibroblastic tumour. METHODS AND RESULTS: We compared the immunohistochemical expression of calponin, h-caldesmon, ALK, and p53 gene mutation and MDM2 gene amplification with clinicopathological findings in 15 cases of inflammatory myofibroblastic tumour. Histologically, cellular atypia was observed in five (33.3%) out of 15 cases. Local recurrences were observed in two (14.3%) of 14 informative cases, but no distant metastasis was observed. The expression of calponin (9/14; 64%) but not h-caldesmon (0/14; 0%) was seen, which suggested myofibroblastic differentiation. ALK expression was seen in eight (53.3%) out of 15 cases, particularly in patients under 40 years old. Nuclear expression of p53 protein was recognized in only one (6.7%) of 15 cases, and polymerase chain reaction single-strand conformation polymorphism followed by direct sequencing revealed p53 gene missense mutations in two (13.3%) of 15 cases. Nuclear expression of MDM2 was seen in four (26.7%) of 15 cases, and the MDM2 gene amplification was observed in two of the four cases. CONCLUSION: Inflammatory myofibroblastic tumour shows a wide spectrum of cellular atypia and biological behaviour with p53 and MDM2 expression. However, the alterations in the p53 pathway seem not to play a major role in the pathogenesis of inflammatory myofibroblastic tumour.

Renal cell carcinoma with rhabdoid features: an aggressive neoplasm.

AIMS: Only a few reports on renal cell carcinoma with rhabdoid features have been published. This study was performed to investigate the clinicopathological characteristics of renal cell carcinomas with rhabdoid features. METHODS AND RESULTS: Among 253 cases of renal cell carcinoma in adults, eight cases with rhabdoid features were detected. Rhabdoid areas ranged from 10% to 90% of each of the cases. Seven of the eight cases were TNM stage III or IV, and four of the eight cases died within 8 months of surgery. Immunohistochemically, the rhabdoid areas were positive for CAM 5.2 (4/8), AE1/AE3 (6/8), epithelial membrane antigen (6/8) and vimentin (8/8), and negative for myogenetic markers (0/8). The mean MIB-1 labelling index in the rhabdoid areas was higher than that in the definite carcinomatous areas. Ultrastructurally, perinuclear whorls of intermediate filaments were demonstrated in three of the eight cases using paraffin-embedded blocks. CONCLUSIONS: The rhabdoid areas in renal cell carcinoma have histological, immunohistochemical and ultrastructural similarities to malignant rhabdoid tumours. Renal cell carcinoma with rhabdoid features is a highly aggressive neoplasm and its malignant behaviour may be due to the high cell-proliferative activity of the rhabdoid areas. Rhabdoid features in renal cell carcinoma may represent the endpoint of clonal evolution of renal cell carcinoma (especially in clear cell type cases).

Calponin and h-caldesmon expression in atypical fibroxanthoma and superficial leiomyosarcoma.

To evaluate smooth muscle differentiation, myogenic markers [desmin, alpha-smooth muscle actin (SMA), and muscle-specific actin (HHF35)] have been widely used. Calponin and h-caldesmon, which are cytoskeleton-associated actin-binding proteins, have been reported to be more specific myogenic markers, especially since myofibroblasts express a small amount of h-caldesmon. Atypical fibroxanthoma (AFX) occurs in the sun-exposed skin of the elderly and follows a benign clinical course. Histologically, AFX, which is a pleomorphic spindle cell tumor and considered to be a superficial variant of malignant fibrous histiocytoma, also mimics leiomyosarcoma. AFX has been thought to differentiate along pathways with fibrohistiocytic and myofibroblastic phenotypes. AFX ( n=10), superficial leiomyosarcoma (S-LMS) ( n=17) and benign fibrous histiocytoma (BFH) ( n=17) were analyzed for myofibroblastic and smooth muscle differentiation immunohistochemically from the viewpoint of comparison. AFX and BFH showed immunoreactivities respectively for calponin (3/10, 11/17), desmin (3/10, 1/17), SMA (3/10, 13/17), and HHF35 (1/10, 5/17), but failed to express h-caldesmon (0/10, 0/17). S-LMS had a high immunoreactive rate of calponin (17/17), desmin (13/17), SMA (16/17), and HHF35 (16/17), while also expressing caldesmon (11/17). The results reveal that AFX and BFH have immunoreactivities for several myogenic markers, with myofibroblastic differentiation (calponin: +/-, h-caldesmon: -), but without the smooth muscle differentiation seen in S-LMS (calponin:+, h-caldesmon: +/-). In addition, calponin and h-caldesmon are considered to be useful markers for distinguishing AFX from S-LMS.

Clinicopathological prognostic factors in soft tissue leiomyosarcoma: a multivariate analysis.

AIMS: Prognostic factors affecting survival in cases of leiomyosarcoma of soft parts were investigated in this study. METHODS AND RESULTS: A retrospective study of 267 patients was carried out. This group comprised 142 females (53%) and 125 males (47%), whose ages ranged from 7 to 95 years (median 58 years). One hundred and five cases were superficially situated (arising from the skin or subcutis), while the remaining 162 cases were deeply situated (subfacial). Nineteen were cases of pleomorphic leiomyosarcoma where the diagnosis had been amended from malignant fibrous histiocytoma to leiomyosarcoma whilst under review. Of the 167 patients with follow-up data, 83 died of leiomyosarcoma. In univariate analysis, depth, tumour size (>or=50 mm), mitotic rate of >20 per 10 high-power fields (HPF), tumour necrosis of >50% and a high stage according to the most recent American Joint Committee on Cancer (AJCC) staging for soft tissue sarcoma were found to lessen significantly the rate of survival (log rank test; P < 0.05). However, in multivariate analysis (Cox's proportional hazards model), tumour size and high AJCC stage were the only factors that were correlated independently with decreased survival. CONCLUSIONS: This study indicates that the most reliable prognostic parameters are tumour size and AJCC stage in leiomyosarcoma.

Matrix metalloproteinase-2 expression correlates with morphological and immunohistochemical epithelial characteristics in synovial sarcoma.

AIMS: Synovial sarcoma is a unique mesenchymal tumour characterized by the presence of epithelial differentiation, although the mechanism involved in the epithelial morphology is still unclear. The aim of this study was to evaluate the function of matrix metalloproteinase-2 (MMP-2) in synovial sarcoma, in order to assess whether MMP-2 expression plays an important role in epithelial differentiation, or whether it contributes to a poor clinical outcome. METHODS AND RESULTS: Immunohistochemical stainings for MMP-2, cytokeratins (CKs) 7, 8, 18 and 19, and E-cadherin were performed for 58 (44 monophasic and 14 biphasic) cases of synovial sarcoma, and we compared the expression of these proteins with the histological and clinical findings. MMP-2 and E-cadherin expression was observed in 43 cases (74.1%) and in 18 cases (31.0%), respectively. Expression of these proteins was preferentially observed in the glandular components of biphasic tumours or the epithelioid areas of monophasic tumours. Statistically significant correlations were recognized between MMP-2 expression and E-cadherin expression of biphasic subtype. Moreover, there were statistically significant correlations between monophasic tumours with epithelioid areas and MMP-2 expression or E-cadherin expression. MMP-2 expression was correlated with epithelial differentiation as assessed by CK immunoreactivity. The expression of MMP-2 did not affect the overall survival rate in synovial sarcoma. CONCLUSIONS: MMP-2 expression seemed to have an important role to play in the epithelial differentiation of tumour cells in synovial sarcoma, through remodelling of the extracellular matrix and by changing the cytoskeletal interaction between the extracellular matrix and tumour cells.

H-, K-, and N-ras gene mutation in atypical fibroxanthoma and malignant fibrous histiocytoma.

Atypical fibroxanthoma (AFX) which is histologically similar to malignant fibrous histiocytoma (MFH), occurs in the sun-exposed skin. The presence of mutations at codons 12 and 13 of the H- and K-ras genes and in exons 1 and 2, which include codons 12, 13, and 61, of the N-ras gene was studied in 8 cases of AFX and 8 cases of storiform-pleomorphic-type MFH using polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-single-conformation polymorphism. Two of the 8 cases of MFH showed ras mutations in the H-ras gene at codon 12 (GGC-AGC) and in the K-ras gene at codon 13 (GGC-GAC). H- and K-ras gene mutations were not seen in any of the cases of AFX (0 of 8). N-ras gene mutation was not detected in either the AFX (0 of 8) or MFH (0 of 8) cases. In conclusion, although the number of cases in this study was small, H- and K-ras genes were present in some of the MFH cases and accordingly may play an important role in the pathogenesis of MFH. In addition, the finding that H-, K-, and N-ras gene mutations are not present in AFX may indicate why AFX has a more favorable behavior than MFH.

Immunoexpression of neurofibromin, S-100 protein, and leu-7 and mutation analysis of the NF1 gene at codon 1423 in osteofibrous dysplasia.

The NF1 (neurofibromatosis type 1, or von Recklinghausen disease) gene, is a tumor-suppressor gene, and its product, neurofibromin, down-regulates ras protein by its guanosine triphosphatase-activating protein (GAP)-related domain. Osteofibrous dysplasia (OFD) is characterized by fibroblast-like spindle cells and osseous tissue and is generally seen in the tibia or fibula during childhood. The precise nature of OFD remains controversial. Cosegregations of OFD and NF1 have been reported, and it has been surmised that OFD is associated with the NF1 gene. We studied the expressions of NF1 gene product (neurofibromin) and so-called Schwann cell markers (S-100 protein, Leu-7) in 17 cases of OFD immunohistochemically. Ten cases of fibrous dysplasia (FD) were also used for the purpose of comparison. Five OFD and 7 FD cases were analyzed for NF1 gene mutation at codon 1423, which is a GAP-related domain, by single-strand conformation polymorphism. Fibroblast-like cells of OFD showed the expression of neurofibromin (5 of 17), S-100 protein (9 of 17), and Leu-7 (5 of 17), and those of FD did not show these expressions, with the exception of 1 case that showed Leu-7 expression. Regarding the OFD cases, significant correspondence was found between cases showing expression of neurofibromin and S-100 protein, between cases showing expression of neurofibromin and Leu-7, and between cases showing expression of S-100 protein and Leu-7 (P < .01). NF1 gene mutation at codon 1423 was not detected in either the OFD (0 of 5) or FD (0 of 7) cases. These results seem to suggest the possible involvement of neurofibromin in the development of OFD, which is associated with the expression of Schwann cell markers (S-100 protein and Leu-7). Furthermore, NF1 gene mutation at codon 1423 did not seem to be related to OFD.

E-cadherin gene mutations frequently occur in synovial sarcoma as a determinant of histological features.

Synovial sarcoma is a mesenchymal tumor that has an epithelial character and two major histological subtypes, the biphasic type and the monophasic fibrous type. However, the mechanisms involved in its epithelial differentiation are unknown, and furthermore, the determinants for histological subtype in synovial sarcoma remain unclear. In this study, we immunohistochemically examined E-cadherin expression and screened for genetic alterations in the E-cadherin gene from exon 4 to exon 9 in 49 cases of synovial sarcoma. In addition, we also examined the mRNA expressions of E-cadherin and Snail, a direct repressor of E-cadherin gene expression, by reverse transcriptase-polymerase chain reaction in 20 samples of frozen material. Immunohistochemical E-cadherin membranous expression was observed in 12 cases (24.5%), and was predominant in biphasic tumors. Single-strand conformation polymorphism analysis followed by DNA direct sequencing revealed 15 missense E-cadherin mutations in 12 cases (24.5%: monophasic, 11 of 42; biphasic, 1 of 6; poorly, 0 of 1) and 7 silent mutations (14.3%) in 7 cases. Ten of the 12 cases with E-cadherin missense mutations did not show E-cadherin membranous expression. Reverse transcriptase-polymerase chain reaction demonstrated E-cadherin and Snail mRNA expressions in 14 cases (70%) and in all cases, respectively. E-cadherin gene expression was inactivated by missense mutations in three of the eight cases (37.5%) of monophasic fibrous tumors that showed E-cadherin mRNA expressions. The E-cadherin gene was potentially inactivated in a significant number of synovial sarcomas. E-cadherin dysfunction because of its mutation in the central region of the molecule was associated with its decreased immunohistochemical expression and histological fibroblastic and spindle-shaped features of monophasic tumors. Thus, E-cadherin gene mutation may be one of the determinants of histological subtype in synovial sarcoma.

beta-catenin nuclear expression correlates with cyclin D1 overexpression in sporadic desmoid tumours.

The immunohistochemical expression of beta-catenin, cyclin D1, Ki-67 and PCNA was Examined in 38 cases of sporadic extra-abdominal or abdominal-wall desmoid tumours without familial adenomatous polyposis (FAP), to evaluate the hypothesis that the accumulated beta-catenin within the nuclei could affect the regulation of the cyclin D1 gene. There was a statistically significant correlation between beta-catenin accumulation and cyclin D1 overexpression (p=0.029). Each group with beta-catenin accumulation or cyclin D1 overexpression showed a higher PCNA-LI than those without, the difference being statistically significant (p=0.007, p=0.004, respectively). Differential PCR was also performed to detect amplification of the cyclin D1 gene and mutational analysis was undertaken for exon 3 of the beta-catenin gene. Amplification of the cyclin D1 gene was observed in 13 out of 22 cases (59.1%). There were nine-point mutations in 7 out of 18 cases (38.9%). The distribution of beta-catenin mutation fell within a wide range, from codon 21 to codon 67. In conclusion, beta-catenin nuclear expression correlated with cyclin D1 overexpression in sporadic desmoid tumours, which could be an in vivo model system for the APC-beta-catenin-Tcf pathway. In addition, beta-catenin mutations in desmoid tumours occurred at an unusually wide range of sites within the gene.

Subcellular distribution of cytokeratin and vimentin in malignant rhabdoid tumor: three-dimensional imaging with confocal laser scanning microscopy and double immunofluorescence.

Malignant rhabdoid tumor (MRT) is a highly aggressive neoplasm that mostly occurs in childhood, characterized histologically by rhabdoid cells as shown by eosinophilic intracytoplasmic inclusions. Although it is known that rhabdoid cells co-express cytokeratin (CK) and vimentin, the distribution patterns of these two kinds of intermediate filaments and structural relationship between them are still not known. We investigated the subcellular distribution of CKs 8 and 18 and vimentin in MRT cell lines (Tm87-16, STM91-01, TTC549, and TC289) using confocal laser scanning microscopy and double immunofluorescence, in addition to ultrastructural examination. Vimentin was diffusely expressed in the cytoplasm of MRT cells, focally forming a filamentous network. In contrast, CKs 8 and 18 were partially expressed in the cytoplasm of MRT cells, forming globules or a few vague agglomerates. Three-dimensional images in TC289 cells revealed distinct distribution patterns of cytokeratin and vimentin, showing agglomerates of cytokeratins within the vimentin filament network. We conclude that these globules and agglomerates of CKs 8 and 18 correspond with the characteristic ultrastructural finding, showing cytoplasmic bundles of intermediate filaments concentrated in whorled arrays.

Immunoreactivity of p53, mdm2, and p21WAF1 in dedifferentiated liposarcoma: special emphasis on the distinct immunophenotype of the well-differentiated component.

Alteration of the p53/mdm2 pathway has been reported in the well-differentiated liposarcoma (WDLS)/dedifferentiated liposarcoma (DDLS) group. We investigated the immunoreactivity of p53, mdm2, and p21WAF1, along with the MIB-1-labeling index (MIB-1-LI) in 21 WDLS and 21 DDLS cases, to clarify the association of these markers with the morphologic changes and the biological factors responsible for the aggressiveness of DDLS. Within DDLS, p53 and p21WAF1 expression and mdm2 overexpression were significantly more prevalent in the dedifferentiated (DD) components than in the well-differentiated (WD) components. The mdm2 overexpression and p21WAF1 expression was significantly associated with sclerosing liposarcomas in both WDLS and the WD components of DDLS. There was no significant difference in the immunoreactivity of p53, mdm2, or p21WAF1 or MIB-1-LI between WDLS and the WD components of DDLS. An association was found between p53 expression and mdm2 overexpression in the WD group (comprising WDLS and WD components of DDLS) and in the DD group, significantly so in the WD group. Notably, this correlation was found in the subtype of sclerosing liposarcoma but not in that of lipoma-like liposarcoma. Within DDLS, the clinical outcome of the nonaccessible soft tissue (non-AST: comprising retroperitoneum and mediastinum) group was significantly worse than that of the accessible soft tissue (AST: comprising extremities, buttocks, axilla, and scrotum) group; however, the immunophenotypes of p53, mdm2, and p21WAF1 and the MIB-1-LI showed no correlation with survival in the AST group alone, in the non-AST group alone, or in the 2 together. This study suggests that the immunoreactivity of p53, mdm2, and p21WAF1 is associated with the morphologic changes, but not with the biological factors responsible for the aggressiveness of DDLS.

Malignant peripheral nerve sheath tumours: high Ki67 labelling index is the significant prognostic indicator.

AIMS: We investigated p53, Ki67, MDM2, and p21WAF1/CIP1 in order to evaluate its relationship with prognosis in malignant peripheral nerve sheath tumours (MPNST). METHODS AND RESULTS: In 49 cases of MPNSTs, the immunohistochemical studies of Ki67, p53, MDM2, p21WAF1/CIP1 and polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) with direct sequencing of p53 were performed with the formalin-fixed paraffin-embedded tissue. In 43 cases with survival data available, an evaluation of the prognostic significance of clinicopathological factors was also carried out. A high Ki67 labelling index (LI) (>25%) was correlated with a reduced survival rate in the 43 cases of MPNST (P=0.0106, log-rank test). Furthermore, there was a significant correlation between the Ki67 LI and the immunohistochemical expression of p53 or MDM2. In 17 MPNST cases, PCR amplification of exons 5 through 8 of the p53 gene was successful. One case showed a base change of codon 240 (AGT-->AGC), but translated amino acid (Ser) remained unchanged. Multivariate Cox analysis of our series showed that the association of von Recklinghausen's disease, tumour depth, and the presence of rhabdomyoblasts (malignant triton tumour) each had an independent negative impact on overall survival. CONCLUSION: High Ki67 LI (>25%) was of significant prognostic value in MPNST.

Malignant peripheral nerve sheath tumour arising within neurofibroma. An immunohistochemical analysis in the comparison between benign and malignant components.

AIMS: To compare the expression of immunohistochemical variables between benign and malignant components of malignant peripheral nerve sheath tumour (MPNST) arising within neurofibroma. METHODS: Eight cases of MPNST arising within a neurofibroma, associated with neurofibromatosis type 1 (NF1), were studied. The areas of MPNST and neurofibroma were compared immunohistochemically with regard to the expression of proliferative activity (MIB-1), growth factors, p53, bcl-2, neural cell adhesion molecule (N-CAM), and CD34. RESULTS: The expression of transforming growth factor beta 1 (TGF-beta 1), TGF-beta receptor type II, hepatocyte growth factor alpha (HGF-alpha), c-met, p53, and N-CAM was higher in the areas of MPNST than in the neurofibromatous areas in four, five, five, eight, five, and three of the eight cases, respectively. CD34 expression was lower in the areas of MPNST than in the neurofibroma areas in three of the eight cases. CONCLUSIONS: On the basis of these findings, TGF-beta 1, HGF-alpha, and p53 might be involved in the malignant transformation of neurofibroma to MPNST.

Pleomorphic leiomyosarcoma: clinicopathologic and immunohistochemical study with special emphasis on its distinction from ordinary leiomyosarcoma and malignant fibrous histiocytoma.

Pleomorphic leiomyosarcoma (PLMS) was recently described as a morphologic variant of leiomyosarcoma; however, its diagnostic criteria, as shown by morphologic features and biologic behavior, remain controversial. We describe 28 cases of pleomorphic sarcoma with pleomorphic areas in more than two thirds of the tumor and an ordinary leiomyosarcomatous fascicular area covering less than one third as PLMS. PLMS comprised 8.6% of all the leiomyosarcomas (322 cases) registered in our institute. Patients ranged in age from 31 to 89 years (average, 57.9 years). Seventeen patients (60.7%) were male and 11 were female. Tumor location was as follows: the extremities in 17 cases, the retroperitoneum or abdominal cavity in 7 cases, the chest/abdominal wall in 3 cases, and the scalp in 1 case. Histologically, all cases showed at least small foci of fascicles consisting of smooth muscle tumor cells, in addition to pleomorphic areas mimicking storiform-pleomorphic malignant fibrous histiocytoma. The border between pleomorphic and leiomyosarcomatous fascicular areas was sharp in 3 cases, gradual in 2 cases, and blending in 23 cases. Sixteen cases (57.1%) showed a typical storiform pattern, 6 cases revealed extensive stromal hyalinization, 6 cases showed a chronic inflammatory infiltrate, 2 cases had the foci of foamy xanthomatous cells, and 7 cases contained myxoid malignant fibrous histiocytoma-like areas covering less than 50% of the tumor. The tumors had a tendency to be of a morphologically higher grade (10 tumors were French Federation of Cancer Centers grade 2, 18 were grade 3). Five of 28 cases (18%) showed rhabdoid features. Immunohistochemically, all of the 28 tumors examined showed a positive reactivity for at least one smooth muscle marker (desmin, muscle-specific actin, and alpha-smooth muscle actin) in the leiomyosarcomatous fascicular areas. In the pleomorphic areas the expression of smooth muscle markers (desmin 10 of 28, muscle-specific actin 13 of 28, and alpha-smooth muscle actin 14 of 28) was significantly reduced, compared with that in leiomyosarcomatous fascicular area (desmin 18 of 28, muscle-specific actin 26 of 28, and alpha-smooth muscle actin 24 of 28). No significant difference was observed between the MIB-1 labeling index in the leiomyosarcomatous fascicular areas (26.10 on average) and that in the pleomorphic areas (26.17 on average). However, the MIB-1 labeling index in PLMS was significantly higher than that in ordinary leiomyosarcoma (n = 20, 12.86 on average) or storiform-pleomorphic malignant fibrous histiocytoma (n = 16, 16.63 on average). In 23 patients follow-up data were available with a duration of 1-239 months. Eleven patients developed metastases, and lung accounted for the most common site of metastasis (9 cases). Fifteen of 23 patients (65.2%) died of disease. Our results indicate that PLMS should be differentiated from ordinary leiomyosarcoma because of its high proliferative activities and rather aggressive biologic behavior.

Cytokeratin subunits of inclusion bodies in rhabdoid cells: immunohistochemical and clinicopathological study of malignant rhabdoid tumor and epithelioid sarcoma.

Extrarenal malignant rhabdoid tumor (MRT), which is recognized as being histologically similar to renal MRT, is characterized by the presence of "rhabdoid cell" (RC) and a highly aggressive biological behavior. Recently it has been proposed that "proximal variant" of epithelioid sarcoma (ES), whose morphology is similar to that of MRT, actually has a more aggressive clinical course than classical type ES. Detailed immunohistochemical analysis of cytokeratin (CK) subunits was performed in 3 cases of extrarenal MRT, 3 cases of renal MRT, and 11 cases of ES comprising 2 "proximal variants" and 9 classical types. Renal and extrarenal MRTs showed positive immunoreactivity for both CK8 and CK18. Classical type ESs were diffusely positive, not only for CK8 and CK18, but also for other cytokeratin subunits including CK4, 6, 10, 13, 16, 17, and "high-molecular-weight" CKs (CK1, 5, 10, and 14). On the other hand, proximal ES revealed limited immunohistochemical reactivity for cytokeratins, compared with classical ES. In conclusion, the inclusion bodies of RCs show immunoreactivity confined to CK8, CK18, and vimentin. Furthermore, ES has additional CK expressions, while proximal ES possesses characteristics intermediate between those of classical ES and those of external MRT.

Expression of intercellular adhesion molecules in epithelioid sarcoma and malignant rhabdoid tumor.

We clinicopathologically evaluated 31 cases of epithelioid sarcoma (ES; 25 'classical' type and six 'proximal variant' type) and six cases of malignant rhabdoid tumor (MRT; three extrarenal and three renal). We also did immunohistochemical studies on 12 classical and three proximal variant cases of ES, and six cases of MRT, to clarify the differences in biological behavior in these tumors. E-cadherin, beta-catenin and CD34 expression was evaluated. We also carried out mutational analysis of exon 3 of the beta-catenin gene by polymerase chain reaction-single-strand conformation polymorphism analysis. In ES, the 5- and 10-year survival rates were 71.1 and 55.3%, respectively. A high mitotic rate (>15/10 high-power fields) was significantly correlated with a poor overall survival rate in ES (P = 0.0248). E-cadherin expression was observed in nine cases (69.2%) of ES and in four cases (66.7%) of MRT. Most of these tumors showed aberrant E-cadherin expression. Seven cases (46.7%) of ES were positive for CD34, although none of the cases of MRT were CD34 positive. Eleven cases (73.3%) of ES were positive for beta-catenin, which was localized to the cellular membrane, whereas all of the cases of MRT were beta-catenin negative. Mutational analysis for the beta-catenin gene was done in nine cases of ES and six cases of MRT, however, genetic alteration was not found. From our results, we conclude that beta-catenin membranous expression could be a useful marker for distinguishing ES, including the proximal variant, from MRT.