Small-cell carcinoma of the gallbladder - a clinicopathological, immunohistochemical and flow cytometric study of 15 cases

Small cell carcinoma (SC) of the gallbladder is an uncommon tumor, and not enough information of this tumor has been previously reported. The SCs in this series occured in nine women and six men (mean age; 64.5 years). Histologically, they consisted of small atypical cells with scanty cytoplasm, hyperchromatic nuclei and inconspicuous nucleoli growing in sheets and cords. Two tumors contained neoplastic glands similar to those of well-differentiated adenocarcinoma and a histological transition between SC and adenocarcinoma was seen in one of the two tumors. Argyrophil granules were present in 10 tumors. The tumor cells were immunoreactive to epithelial markers (epithelial membrane antigen: 12/14; AE1/AE3: 12/14; CAM 5.2: 9/14; carcinoembryonic antigen: 7/14) and neuroendocrine markers (neuron specific enolase: 11/14; chromagranin A: 4/14; Leu 7: 10/14; adrenocorticotrophic hormone: 6/14). Abnormalities in tumor suppressor gene p53 expression were found in 9 of 14 SCs by using monoclonal antibody PAb 1801. Flow cytometry revealed aneuploidy in 7 (78%) of 9 in the SC and 26 (40%) of 65 in the adenocarcinoma. The survival curve of the SCs was less favorable than that of papillary adenocarcinoma and well differentiated adenocarcinoma in pTNM stage 2-4 (P=0.0027, P=0.0017, respectively). These results suggested that the SCs of the gallbladder arose from common primitive cells capable of endocrine and epithelial differentiation, while most SCs (78%) showed DNA aneuploid by flow cytometry and their prognosis was worse than that of differentiated adenocarcinoma of the gallbladder.

Isolation and characterisation of cytopathic avian enteroviruses from broiler chicks

Cytopathic viruses were isolated from the faeces, pancreas and caecal contents of broiler chicks in two cases of a stunting syndrome. Two representative strains, designated AAF7 and M-8, were identified as enteroviruses on the basis of their size (25 nm in diameter), RNA in the viral core, virus growth in the cytoplasm, resistance to chloroform, trypsin and acid, and partial heat-stabilisation to molar magnesium chloride. They formed irregular plaques in chick kidney cell cultures. Numerous granula eosinophilic inclusions were induced in the cytoplasm of chicken kidney cell cultures infected with the viruses. Both isolates reacted partially with the G4260 strain of avian nephritis virus but not with the VR strain of avian encephalomyelitis virus.

Flat adenoma-carcinoma sequence with high-malignancy potential as demonstrated by CD10 and beta-catenin expression: a different pathway from the polypoid adenoma-carcinoma sequence

AIMS

CD10+ colorectal carcinomas have a high risk of giving rise to liver metastasis. The aim was to examine phenotypic expression in colorectal neoplasia and to elucidate changes in such expression through the adenoma-carcinoma sequence.

METHODS AND RESULTS

We examined the expression of various proteins immunohistochemically in 111 flat [non-polypoid growth (NPG)] colorectal neoplasms, categorized into 28 low-grade (NPG-LGN), 44 high-grades (NPG-HGN) and 39 cases of invasive neoplasia (NPG-IN), as well as in 96 polypoid [polypoid growth (PG)] neoplasms, categorized into 26 PG-LGN, 39 PG-HGN and 31 PG-IN according to the Vienna classification. CD10 was more frequently expressed in NPG than in PG neoplasia. MUC2 and MUC5AC were more frequently expressed in PG than in NPG neoplasias. Nuclear beta-catenin was more frequently expressed in NPG-LGN than in PG-LGN. No difference in p53 expression was found between NPG and PG neoplasia.

CONCLUSIONS

From the viewpoint of the expression of CD10 and beta-catenin, it would appear that NPG-LGN differs significantly from PG-LGN, thereby indicating that NPG-LGN is a precursor of CD10+ carcinoma. It is important to ensure that NPG neoplasia is not overlooked if cases of CD10+ carcinoma are to be detected at an early stage.

Over-expression of S100A2 in pancreatic cancer correlates with progression and poor prognosis

Controversy exists regarding the clinical significance of S100A2 in the progression of tumours. In pancreatic cancer, little is known about the role of S100A2. The aim of this study was to clarify the clinical significance of S100A2 expression in pancreatic carcinogenesis. We microdissected invasive ductal carcinoma (IDC) cells from 22 lesions, pancreatic intraepithelial neoplasia (PanIN) cells from five lesions, intraductal papillary mucinous neoplasm (IPMN) cells from 38 lesions, pancreatitis-affected epithelial (PAE) cells from 16 lesions, and normal ductal cells from 18 normal pancreatic tissues. S100A2 expression in 14 pancreatic cancer cell lines, microdissected cells and formalin-fixed paraffin-embedded (FFPE) samples was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Microdissection analyses revealed that IDC cells expressed higher levels of S100A2 than did IPMN, PAE or normal cells (all comparisons, p < 0.007). Cell lines from metastatic sites expressed higher levels of S100A2 than those from primary sites. PanIN cells expressed higher levels of S100A2 than normal cells (p = 0.018). IDC cells associated with poorly differentiated adenocarcinoma expressed higher levels of S100A2 than did IDC cells without poorly differentiated adenocarcinoma (p = 0.006). Analyses of FFPE samples revealed that levels of S100A2 were higher in samples from patients who survived < 1000 days after surgery than in those from patients who survived > 1000 days (p = 0.043). Immunohistochemical analysis was consistent with qRT-PCR. S100A2 may be a marker of tumour progression or prognosis in pancreatic carcinogenesis and pancreatic cancer.

Squamous cell carcinoma arising in mature cystic teratoma of the ovary: an immunohistochemical analysis of its tumorigenesis

AIMS

Squamous cell carcinoma (SCC) is the most common form of malignant transformation in mature cystic teratoma (MCT) of the ovary. Some investigators have suggested the possibility of origin from columnar epithelium. The aim of this study was to analyse such tumours immunohistochemically to elucidate their histogenesis.

METHODS AND RESULTS

The expression of cytokeratin (CK) 10 and CK18 was examined in 21 samples of SCC arising in MCT. The expression of CK10 and CK18 was also assessed in SCCs arising in different organs (skin, vulva, lung and uterine cervix) for the purpose of comparison. SCC in MCT expressed CK10 in 7/21 cases [33.3%, 95% confidence interval (CI) 0.12-0.53] and CK18 in 14/21 cases (66.7%, 95% CI 0.46-0.87). SCC in MCT expressed CK10 less frequently, but CK18 more frequently, as is the case in SCCs of the uterine cervix (CK10, 20%; CK18, 70%) and the lung (CK10, 5%; CK18, 90%), both of which are derived from columnar epithelium by squamous metaplasia.

CONCLUSIONS

SCC in MCT may be derived from metaplastic squamous epithelium.

A case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

Oxidative stress and DNA hypermethylation status in renal cell carcinoma arising in patients on dialysis

Renal cell carcinoma (RCC) is more frequently observed in patients on dialysis than in patients with normal renal function. However, the mechanism underlying carcinogenesis in RCC patients on dialysis is still unclear. We hypothesized that oxidative stress affects patients on dialysis and generates new neoplasms, and therefore analysed the correlation between the influences of various markers of oxidative stress and carcinogenesis in those patients. We evaluated the immunohistochemical expression of oxidative stress markers, such as iNOS, 8-OHdG, and COX-2 in 42 cases on dialysis and 51 cases with normal renal function as a control. The methylation status of p16INK4a, p14ARF, VHL, and RASSF1A was analysed together with clinicopathological factors. Histologically, the papillary type was observed more frequently in dialysis RCC than in sporadic RCC. Immunohistochemically, overexpression of iNOS (p < 0.0001) and COX-2 (p = 0.0002) was more frequently observed in dialysis RCC. Furthermore, the 8-OHdG labelling index was significantly higher in dialysis RCC than in sporadic RCC. Hypermethylation of p16INK4a was more frequently found in dialysis RCC (p < 0.05). However, no significant correlations between oxidative stress markers and DNA hypermethylation status were observed. The overexpression of iNOS, COX-2, and 8-OHdG in dialysis RCC suggests that patients on dialysis are affected by oxidative stress and that this effect plays an important role in the genesis of dialysis RCC.

Association between the HER2 expression and histological differentiation in Wilms tumor

Human epidermal growth factor receptors (HER) play a critical role in the branching morphogenesis of renal tubules. In the current study, we analyzed the expression of HER2 in Wilms tumor and assessed the role of this gene in the tumorgenesis of Wilms tumor. During the period from 1960 to 2005, 40 patients with Wilms tumor were treated in our department. Twenty-four of those patients (except those with clear cell sarcoma of the kidney and malignant rhabdoid tumor of the kidney) were collected and assessed. The histological component of each Wilms tumor was divided into three categories (epithelial, blastemal, and mesenchymal) and the extent of HER2 protein expression was analyzed immunohistochemically. The normal kidney tissue accompanied with 12 cases of Wilms tumor was also examined. In the normal kidney, HER2 showed a strong immunoreactivity in the cell membranes of the collecting tubules and in the endothelial cells. Of 24 cases, 15 cases showed an epithelial component, while 24 cases had a blastemal component and 21 cases had a mesenchymal component, respectively. Among the 15 specimens with epithelial cell differentiation, eight (53.3%) showed HER2 immunoreactive epithelial cells. HER2 immunoreactive blastemal cells were present in 11 (45.8%) of 24 specimens with blastemal cells. On the other hand, only 3 (14.3%) of 21 specimens containing mesenchymal cells showed HER2 immunoreactivity. These results suggest that the extent of HER2 expression is associated with epithelial differentiation in Wilms tumor. These histological findings may therefore help to explain the development of Wilms tumor from the standpoint of histological differentiation.

Sonic hedgehog is an early developmental marker of intraductal papillary mucinous neoplasms: clinical implications of mRNA levels in pancreatic juice

Intraductal papillary mucinous neoplasms (IPMNs) are common cystic tumours of the pancreas. Sonic hedgehog (SHH) is involved in gastric epithelial differentiation and pancreatic carcinogenesis. However, a comprehensive analysis of SHH expression in IPMN has not yet been performed. In the present study, one-step quantitative real-time reverse transcription-polymerase chain reaction with gene-specific priming was used to examine mRNA levels in various types of clinical samples. SHH expression in IPMN was measured and the possible association of gastric epithelial differentiation with development of IPMN was evaluated. In bulk tissue analyses (IPMNs, 11 pancreatic cancer, and 20 normal pancreatic tissues), IPMN expressed significantly higher levels of SHH than did normal pancreas (IPMN versus normal pancreas, p = 0.0025; pancreatic cancer versus normal pancreas, p = 0.0132), but SHH expression did not differ between IPMN and pancreatic cancer (p = 0.3409). In microdissection analyses (infiltrating ductal carcinoma cells from 20 sections, IPMN cells from 20 sections, pancreatitis-affected epithelial cells from 11 sections, and normal epithelial cells from 12 sections), IPMN cells expressed significantly higher levels of SHH than did cancer cells, normal cells, or pancreatitis-affected ductal cells (all comparisons, p < 0.008). Pancreatic juice analyses (20 samples from pancreatic cancers, 31 samples from IPMNs, and 27 samples from chronic pancreatitis) revealed that SHH expression differed significantly between IPMN juice and pancreatitis juice (p < 0.0001), and between cancer juice and pancreatitis juice (p = 0.0125). Receiver operating characteristic curve analyses revealed that SHH measurement in pancreatic juice was useful for discriminating IPMN from chronic pancreatitis (area under the curve = 0.915; 95% confidence interval: 0.796-0.976). The data suggest that overexpression of SHH is an early event in the development of IPMN and that SHH measurement in pancreatic juice may provide some advantages for the treatment or follow-up of a subset of patients with IPMN or chronic pancreatitis.

Gastric mucin phenotype defines tumour progression and prognosis of intrahepatic cholangiocarcinoma: gastric foveolar type is associated with aggressive tumour behaviour

AIMS

To identify the role of mucus core protein (MUC) in intrahepatic cholangiocarcinoma (ICC).

METHODS AND RESULTS

We examined the expression profile of MUC2, MUC5AC and MUC6 by immunohistochemical staining in 100 ICCs and compared the clinicopathological factors and the immunohistochemical results. The expression frequency was: MUC2, 9%; MUC5AC, 40%; and MUC6, 21%. According to the gastric mucin expression profile, ICCs were classified into the following groups: null type (n = 43), gastric foveolar type (n = 36), pyloric gland type (n = 11) and gastric combined type (n = 10). Half of the gastric foveolar type and the gastric combined type were located in the hilar region, but the other types were predominant at the periphery (P = 0.0004). Well-differentiated components were more often detected in the gastric combined type and the pyloric gland type (P = 0.0281). The gastric foveolar type was associated with a higher incidence of lymph node metastasis (P < 0.0001). The pyloric gland type was associated with better survival and the gastric foveolar type was associated with worse survival. The gastric mucin phenotype was an independent prognostic factor by multivariate survival analysis.

CONCLUSION

The gastric foveolar type of ICC was more often associated with aggressive tumour development, whereas the pyloric gland type exhibited less aggressive behaviour.

Gli1, downregulated in colorectal cancers, inhibits proliferation of colon cancer cells involving Wnt signalling activation

BACKGROUND

Early events in the progression of 90% of sporadic colorectal cancers depend on constitutive activation of Wnt signalling. Recent data also indicate a close association between the Hedgehog (Hh) and Wnt pathways in colonic epithelial cell differentiation.

AIMS

To investigate whether expression of Gli1, a transactivator of Hh signalling, can suppress Wnt signalling and inhibit proliferation of human colorectal cancer cells.

METHODS

Gli1 and nuclear beta-catenin expression were examined in a series of 40 human colorectal cancers by immunohistochemistry. We quantified Gli1 and nuclear beta-catenin staining as markers of Hh and Wnt pathway activation, respectively. Two human colon cancer cell lines, SW480 and HCT116, with mutations in APC and beta-catenin, respectively, were used. The effects of Gli1 overexpression on Wnt transcriptional activity, beta-catenin subcellular distribution, and proliferation in these cells were analysed.

RESULTS

Nuclear accumulation of beta-catenin and the Gli1 staining level were inversely associated in the 40 human colorectal cancers. Wnt transcriptional activity was reduced in Gli1 transfected cells. These effects were observed even in Gli1 transfected cells cotransfected with mutated beta-catenin. Furthermore, nuclear accumulation of beta-catenin was diminished compared with that in empty vector transfected cells, and downregulated transcription of c-Myc was observed in Gli1 transfected cells. Proliferation of Gli1 transfected cells was also significantly suppressed compared with that in empty vector transfected cells.

CONCLUSIONS

Our data suggest that Gli1 plays an inhibitory role in the development of colorectal cancer involving Wnt signalling, even in cases with the stabilising mutation of beta-catenin.

Clinical characteristics and the prognosis of rhabdomyosarcoma - a report from the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

AIM

There have been no nationwide group studies for patients with rhabdomyosarcoma in Japan. This study aims to assess the actual state of treatments and their outcome.

PATIENTS AND METHODS

From 1982 to 1996, 79 rhabdomyosarcomas were registered by the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area. The prognostic factors and treatments were assessed based on the 5-year survival rate. The staging was done according to the Intergroup Rhabdomyosarcoma Study (IRS) Clinical Grouping Classification.

RESULTS

The 5-year survival rate for all patients was 39.1 %. The survival rates for each factor were as follows, according to 1) group; 77.8 % for Group I, 51.9 % for Group II, 33.7 % for Group III, and 20.2 % for Group IV; 2) primary site: 56.3 % for the head and neck, 43.8 % for the parameningeal region, 12.5 % for the extremity, 58.3 % for the genitourinary region, and 30.5 % for the others; 3) histology: 35.8 % for the embryonal type, 36.8 % for the alveolar type.

CONCLUSIONS

Altogether, the outcome of this study was poor. To improve outcomes, a new nationwide group study for rhabdomyosarcoma, which we belong to, has just started in Japan.

Loss of phenotypic expression is related to tumour progression in early gastric differentiated adenocarcinoma

AIMS

To evaluate the relationship between phenotypic expression and tumour progression as represented by macroscopic features, submucosal invasion and lymph node metastasis in early differentiated gastric adenocarcinoma.

METHODS

One hundred and fifty-five cases of early gastric differentiated adenocarcinoma without any poorly differentiated components were studied. The mucosal and submucosal components of carcinomas and lymph node metastatic lesions were classified into four categories, gastric type (G-type), incomplete intestinal type (I-type), complete intestinal type (C-type) and unclassified type (U-type), based on the combination of the phenotypic expression of HGM (gastric foveolar epithelium), MUC 6 (gastric pyloric glands), MUC 2 (intestinal goblet cells) and CD 10 (small intestinal brush border). In addition, a new classification representing a phenotypic shift from mucosa to submucosa or from primary lesion to lymph node metastasis was established with the categories of preserved group (P-group), loss group (L-group) and acquired group (A-group).

RESULTS

(1) In submucosal carcinoma, U-type was more common in the submucosa (39%) than in the mucosa (9%). (2) U-type was more common in the metastatic lesions (42%) than in the primary lesions (5%). (3) The submucosal component and lymph node metastatic lesions were classified as P-group in 48% and 43% of cases, respectively, and as L-group in 50% and 52% of cases, respectively. (4) Lymph node metastatic lesions comprising undifferentiated carcinoma were classified as L-group in 100% of cases.

CONCLUSION

During the course of tumour progression, early differentiated adenocarcinoma at first tends to lose its phenotypic expression despite preserving its morphology, but subsequently morphological dedifferentiation occurs.

'Scirrhous' type hepatocellular carcinomas: a special reference to expression of cytokeratin 7 and hepatocyte paraffin 1

AIMS

'Scirrhous' hepatocellular carcinoma (scirrhous HCC) is extremely rare and its characteristics remain unclear. We investigated the clinicopathological and immunohistochemical features of scirrhous HCC, compared with those of ordinary hepatocellular carcinoma (ordinary HCC).

METHODS AND RESULTS

We compared the clinicopathological and immunohistochemical features of 20 resected cases of scirrhous HCC with those of 69 resected cases of ordinary HCC. Scirrhous HCC was characterized by its gross and histological findings, such as a higher proportion of contiguous multinodular type tumours, the absence of a complete fibrous capsule around the tumour, the absence of tumour necrosis and highly preserved portal tracts in the tumour. The immunohistochemical results revealed a significantly higher expression of cytokeratin 7 and a significantly lower expression of hepatocyte paraffin 1 in scirrhous HCC than in ordinary HCC (P<0.0001, respectively). There were no significant differences in proliferative activity and survival curves between the patients with scirrhous HCC and those with ordinary HCC.

CONCLUSION

Scirrhous HCC has several particular gross, histological and immunohistochemical features. In particular, we would like to emphasize the greater immunohistochemical expression of cytokeratin 7 and lower expression of hepatocyte paraffin 1 in scirrhous HCC than in ordinary HCC.

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.

Phenotypic alteration in malignant transformation of colonic villous tumours: with special reference to a comparison with tubular tumours

AIMS

To clarify the cellular differentiation of colorectal villous tumours in malignant transformation, compared with that of tubular tumours (tubular adenoma and adenocarcinoma arising in tubular adenoma).

METHODS AND RESULTS

Forty-nine cases of colorectal villous tumours [six cases of low-grade villous adenoma, 21 of high-grade villous adenoma (VA), nine of invasive carcinoma in villous adenoma (CIVA), and 13 of pure villous carcinoma (PVC)] and 46 cases of tubular tumours [14 cases of low-grade and 17 of high-grade tubular adenoma (TA), and 15 cases of carcinoma in tubular adenoma (CITA)] were selected for this study based on their expression patterns of CD10 (small intestinal brush border), MUC2 (intestinal goblet cell), and HGM (gastric foveolar epithelium). HGM was more frequently expressed in the adenomatous components of villous tumours (63%) than in those of tubular tumours (14%) (P < 0.05). CD10 expression of high-grade TAs (47%) and carcinomas arising in TA (60%) was significantly higher than that of villous tumours (0%) (P < 0.05).

CONCLUSIONS

There were significant differences in the phenotypic expression of adenoma and adenocarcinoma between villous and tubular tumours, respectively. Villous tumours have a pathway of malignant transformation different from that of tubular tumours. Because of biological differences, colorectal villous tumours should be distinguished from tubular neoplasia. The analysis of the phenotype of colorectal neoplasms is useful for the evaluation of tumour progression.

Improved survival outcome for hepatoblastoma based on an optimal chemotherapeutic regimen--a report from the study group for pediatric solid malignant tumors in the Kyushu area

BACKGROUND/PURPOSE

The survival outcome for patients with hepatoblastoma normally depends on the resectability of the tumor. In Japan, the pre and/or postoperative chemotherapy protocol using a combination of cisplatin (CDDP) and tetrahydropyranyl-Adriamycin (THP-ADR) has been the standard treatment since 1991. This study aims to assess exactly what influence the establishment of this chemotherapy protocol has had on both the tumor resectability and the outcome of patients with hepatoblastoma.

METHODS

From 1982 to 1997, 60 patients with hepatoblatoma were treated in the Kyushu area, Japan. Based on the pretreatment extent of disease (PRETEXT), the outcome and tumor resectability were compared between group A (1982 to 1990, n = 27, PRETEXT I:5, II:8, III:6, IV:8) and group B (1991 to 1997, n = 33, PRETEXT I:9, II:9, III:5, IV:10).

RESULTS

The 5-year survival rates (group A and group B) were 33% and 73% for all cases (P <.01), 100% and 89% for PRETEXT I, 38% and 89% for II (P <.05), 17% and 80% for III (P <.01), and 0% and 40% for IV (P <.01), respectively. The 5-year survival rates for patients with metastases were 0% for group A (n = 5) and 57% for group B (n = 7; P <.01). The rates of a complete resection of primary tumor were 48% for group A and 67% for group B. In particular, a significant difference was found regarding the complete resection rate between groups A and B in the patients with PRETEXT III (17% for group A and 80% for group B; P <.01). In the patients with an incomplete tumor resection (14 for group A, 11 for group B), the 5-year survival rates were 0% for group A and 45% for group B (P <.01).

CONCLUSIONS

The optimal chemotherapeutic regimen of CDDP and THP-ADR was thus found to greatly contribute to the improved survival rate of hepatoblastoma patients. Preoperative chemotherapy resulted in an increased resectability of the tumor, whereas postoperative chemotherapy played an important role in the increased cure rate of cases with either an incomplete tumor resection or metastasis. However, refractory cases with PRETEXT IV or metastasis may still require the development of an even more effective treatment modality, including the use of blood stem cell transplantation.

Angiopoietin switching regulates angiogenesis and progression of human hepatocellular carcinoma

AIM

Angiopoietin 1 (Ang-1) and its antagonist, angiopoietin 2 (Ang-2), are novel ligands that regulate the Tie2 receptor. The Ang-2 gene is upregulated in the hypervascular type of human hepatocellular carcinoma (HCC). To gain a better understanding of the role of the Ang-Tie2 system in HCC the expression of these genes was investigated in a series of human HCCs.

METHODS

The expression of the angiopoietin and Tie2 proteins was investigated in nine normal liver tissues and 52 surgically resected HCCs. In addition, the effects of hypoxic stimuli on Ang-1, Ang-2, vascular endothelial growth factor (VEGF), and erythropoietin (EPO) expression was investigated in Hep3B cells.

RESULTS

Ang-1, rather than Ang-2, was more frequently expressed in the normal liver. Ang-1 was expressed in 68% of HCCs, whereas Ang-2 was expressed in 81%, and was significantly higher in poorly differentiated HCCs characterised by high vascularity (p = 0.02), and in tumours with a peliotic change (p = 0.02). Strong expression of Tie2 was seen in tumour vessels in accordance with Ang-2 expression. In Hep3B cells, hypoxic stimuli upregulated VEGF and EPO, but not Ang-1 or Ang-2.

CONCLUSIONS

These data support the evidence that the reversal of Ang-1 and Ang-2 expression plays an important role in the angiogenic and dedifferentiation processes in HCC. The hypoxic stimuli were not responsible for Ang-2 upregulation, unlike that of VEGF, in human HCC cells.

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.

Chromosomal translocation t(11;18)(q21;q21) in gastrointestinal mucosa associated lymphoid tissue lymphoma

AIMS

To evaluate the chromosomal translocation t(11;18)(q21;q21) in gastrointestinal lymphomas.

METHODS

A possible API2-MLT fusion transcript specific to t(11;18)(q21;q21) was examined by means of reverse transcription-polymerase chain reaction (RT-PCR) in tumours from 47 cases of primary gastrointestinal lymphoma (28 low grade mucosa associated lymphoid tissue (MALT) lymphomas, four low grade MALT lymphomas with a high grade component, nine secondary diffuse large B cell lymphomas, four primary diffuse large B cell lymphomas, and two T cell lymphomas).

RESULTS

API2-MLT fusion was seen in four of 28 cases of low grade MALT lymphoma, but it was not seen in other types of lymphoma. Among the low grade MALT lymphomas, the fusion transcript was seen more frequently in colonic tumours than in gastric tumours (two of three compared with two of 24) and in tumours with submucosal invasion than in those confined to the mucosa (four of 13 compared with 0 of 15). Helicobacter pylori negative tumours tended to show a higher positive rate than H pylori positive tumours (three of six compared with one of 21). None of the gastric tumours that responded to H pylori eradication expressed the API2-MLT fusion transcript.

CONCLUSIONS

t(11;18)(q21;q21) seems to be one of the genetic alterations related to the development of gastrointestinal low grade MALT lymphoma. Such translocations may be predominantly associated with the development of intestinal MALT lymphoma.

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).

Malignant germ cell tumors: clinical characteristics, treatment, and outcome. A report from the study group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

PURPOSE

This study aims to assess the prognostic factors and optimal treatments for malignant germ cell tumors (MGCT) in childhood.

METHODS

Among 117 MGCT, the clinical features were analyzed. Regarding the histology, there were 89 embryonal carcinomas, 13 dysgerminomas, 4 choriocarcinomas, and 11 others. The prognostic factors and treatments were assessed based on the 5-year survival rate.

RESULTS

(1) Stage: 100% for stage I (n = 54), 75.0% for stage II (n = 4), 67.3% for stage III (n = 14), and 54.8% for stage IV (n = 33); Unknown: n = 12. (2) Primary site: 93.4% for the testis (n = 52), 86.7% for the ovary (n = 31), 56.9% for the sacrococcygeal (n = 21), and 60.6% for others (n = 12); unknown: n = 1. (3) Surgical intervention for primary tumor: 100% for stage I with a complete resection (n = 53), 78.4% for stage III, IV with a complete resection (n = 26), and 33.3% for stage III, IV with an incomplete resection (n = 21). (4) Type of chemotherapy for the stage III and IV: 83.9% for the PVB (cisplatin, vinblastin, bleomycin; n = 13), 66.7% for the VAC (vincristine, actinomycin D, cyclophosphamide; n = 6), and 47.1% for other regimens (n = 25).

CONCLUSIONS

An early stage, a diagnosis under 1 year of age and a primary site in the gonads were favorable prognosis factors, whereas histologic findings of choriocarcinoma and liver or lung metastasis were unfavorable. Radical complete resection alone is a sufficient treatment for localized MGCT. The PVB regimen is optimal chemotherapy for advanced MGCT; however, high-risk cases still may require more aggressive treatment.

Differences in p53 and cadherin-catenin complex expression between histological subtypes in diffusely infiltrating gastric carcinoma

AIMS

The aim of this study was to elucidate possible clinicopathological differences between diffusely infiltrating gastric carcinoma of 'pure type' (poorly differentiated carcinoma without any glandular component) and 'mixed type' (coexistence of poorly differentiated carcinoma and intramucosal glandular component).

METHODS AND RESULTS

The clinicopathological features and immunohistochemical expression of p53 and intercellular adhesion molecules (E-cadherin and alpha-, beta- and gamma-catenins) were compared between the patients with pure (n=59) and mixed (n=56) types of diffusely infiltrating gastric carcinoma. Intestinal metaplasia (P < 0.01), prominent lymphatic permeation (P < 0.001) and lymph node metastasis (P < 0.05) were more frequently observed in mixed type than in pure type, while survival probability did not differ between the two groups. The frequency of p53 over-expression was higher in mixed type (56%) than in pure-type (19%) (P < 0.001). In mixed type, p53 expression was not different between glandular and poorly differentiated components. By contrast, the expression of adhesion molecules was more frequently preserved in glandular components than in poorly differentiated components.

CONCLUSIONS

These two subtypes seem to be different in nature and biological behaviour. The preservation of adhesion molecules in mixed type may be associated with higher incidence of lymphatic permeation and lymph node metastasis.

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.

c-erbB-2 and c-Met expression relates to cholangiocarcinogenesis and progression of intrahepatic cholangiocarcinoma

AIMS

The c-erbB-2 and c-Met proto-oncogenes are important for tumour invasiveness and metastasis in many types of malignant tumours. Previous studies have indicated that these proteins are associated with carcinogenesis in intrahepatic cholangiocarcinoma. In this study, we examined c-erbB-2 and c-Met expression by immunohistochemistry in hepatolithiasis, intrahepatic cholangiocarcinoma and metastatic lymph node, in order to clarify whether these proteins play a role in carcinogenesis and tumour metastasis in intrahepatic cholangiocarcinoma.

METHODS AND RESULTS

In hepatolithiasis, the staining for c-erbB-2 was positive in 14 of the 23 (61%) cases, while staining for c-Met was positive in eight of the 23 (35%) cases. In intrahepatic cholangiocarcinoma, staining for c-erbB-2 was positive in 45 of the 81 (55%) cases, while staining for c-Met was positive in 28 (35%) cases. The positivity of c-Met staining in intrahepatic cholangiocarcinoma was significantly higher in the differentiated type of cholangiocarcinoma than in the undifferentiated type. In addition, c-Met-positive staining had an inverted correlation with tumour size, the presence of perineural invasion and the presence of lymph node metastasis. c-Met staining had a significantly higher positivity in cases at an early stage of intrahepatic cholangiocarcinoma. In contrast, the positivity of c-erbB-2 staining in intrahepatic cholangiocarcinoma was significantly higher in cases with lymph node metastasis than in cases without. In metastatic lymph nodes, the staining for c-erbB-2 was positive in 20 of the 25 (80%) cases, while staining for c-Met was positive in six of the 25 (24%) cases. There was no difference in survival between c-erbB-2-positive and negative patients. However, the patients with c-Met-positive tumours had a significantly longer survival than those with c-Met-negative tumours in the medium survival term. The multivariate analysis showed the presence of lymph node metastasis, lymphatic permeation and histological differentiation to be independent prognostic factors.

CONCLUSION

These results indicate that increased c-Met expression participates in cholangiocarcinogenesis and in the early developmental stages of intrahepatic cholangiocarcinoma, while increased c-erbB-2 expression contributes to the development of cholangiocarcinogenesis into an advanced stage associated with tumour metastasis.

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.

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.

Immunohistochemical analysis of E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM) in chordoma

AIMS

The epithelioid features seen in chordoma are unique among mesenchymal tumours. However, no detailed analysis regarding cell-cell communication has been conducted in this epithelioid tumour. The aims of this study were to investigate cell-cell communication in chordoma.

METHODS

By means of immunohistochemical techniques that incorporated a panel of monoclonal antibodies against cell adhesion molecules (CAMs), including E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM), the expression of CAMs was studied in 15 specimens of chordoma and eight specimens of chondrosarcoma.

RESULTS

Most chordoma specimens showed some positive immunoreactivity for all the CAMs examined. For the various CAMs investigated, between two and five cases showed diffuse immunoreactions, indicating well preserved expression. Well preserved expression of all the CAMs examined was limited to only one case, thus indicating that the expression of CAMs was decreased in most of the chordoma specimens; however, no significant correlation was found between the decreased expression of CAMs and the histological grade of malignancy, cellular growth pattern, or clinical parameters in chordoma. In chondrosarcoma, only a few specimens showed positive immunoreactivity for CAMs and the expression of E-cadherin, beta-catenin, gamma-catenin, and NCAM was seen more frequently in the chordoma specimens than in the chondrosarcoma specimens.

CONCLUSIONS

These results suggest that the expression of CAMs is associated with the formation and maintenance of chordoma tissue architecture, just as it is in other epithelial tumours or normal tissue. Immunohistochemistry for CAMs was found to be of diagnostic value for discriminating chordoma from chondrosarcoma, and these markers could be used along with the cytokeratins, which are already used for this purpose.

Nuclear factor-kappaB p65 (RelA) transcription factor is constitutively activated in human gastric carcinoma tissue

PURPOSE

Activation of transcription factor nuclear factor-kappaB (NF-kappaB) has been shown to play a role in cell proliferation, apoptosis, cytokine production, and oncogenesis. The purpose of this study was to determine whether NF-kappaB is constitutively activated in human gastric carcinoma tissues and, if so, to determine any correlation between NF-kappaB activity and clinicopathological features of gastric carcinoma.

EXPERIMENTAL DESIGN

NF-kappaB activation was determined by immunohistochemical analysis of formalin-fixed, paraffin-embedded specimens from 64 gastric carcinoma patients. We quantified nuclear staining of RelA as a marker of NF-kappaB activation.

RESULTS

Nuclear translocation of RelA was significantly high in tumor cells in comparison to that in adjacent normal epithelial cells (22.5 +/- 2.4% versus 8.6 +/- 1.5%, P < 0.0001). There was a significant correlation between NF-kappaB activation (nuclear translocation of RelA) and expression of urokinase-type plasminogen activator, an invasion-related factor and target of NF-kappaB in tumor cells (rho = 0.393; P = 0.0013). NF-kappaB activation was correlated with tumor invasion-related clinicopathological features such as lymphatic invasion of tumor cells (P = 0.0126), depth of invasion (P = 0.0539), peritoneal metastases (P = 0.0538), and tumor size (P = 0.0164).

CONCLUSIONS

Collectively, the data show that NF-kappaB is constitutively activated in human gastric carcinoma tissues and suggest that NF-kappaB activity is related to tumor progression due to its transcriptional regulation of invasion-related factors such as urokinase-type plasminogen activator.

Decreased expression of an ATP-binding cassette transporter, MRP2, in human livers with hepatitis C virus infection

BACKGROUND/AIMS

To understand hepatic injury during the process of hepatitis viral infection, determination of liver-specific functions at molecular levels is critical. Because the transport of endogenous/exogenous toxic substances is an intrinsically important hepatic function, we examined whether expression of the ATP-binding cassette (ABC) transporter gene was affected in patients with hepatitis viral infection.

METHODS

To determine which ABC transporter was expressed differently in patients with hepatic viral infection, we assayed the expression of MDR1, MDR3, MRP1, MRP2, and MRP3 in non-cancerous regions in the liver of 42 patients with hepatic tumors using both quantitative RT-PCR and immunological staining analysis, and compared the hepatic expression levels between patients with hepatitis viral infection and non-infected controls.

RESULTS

Of the five ABC transporter genes studied, the mRNAs of MRP2 and MRP3 were highly expressed in the human liver. There was a significant reduction in MRP2 expression to 29% in the virus-infected liver. Treatment of hepatic cells with inflammatory cytokines resulted in decreased mRNA levels of MRP2 and decreased MRP2 promoter activity.

CONCLUSIONS

The down-regulation of MRP2 might induce a failure in the transport of various genotoxic substances in the liver with hepatitis virus infection.

Secondary malignant giant-cell tumour of bone: molecular abnormalities of p53 and H-ras gene correlated with malignant transformation

AIMS

We report two cases of secondary malignant giant-cell tumour occurring without irradiation therapy. To elucidate the mechanism of malignant transformation in this tumour, we searched for the molecular abnormalities of p53, MDM2 and the H-ras genes.

METHODS AND RESULTS

These cases were retrieved after a review of 103 cases of primary giant-cell tumour of bone, registered in our institute. One case occurred in the distal femur of a 42-year-old female after surgical curettage, while the other arose in the acetabulum of a 25-year-old male after en bloc resection. Microscopically, the malignant tumour in the distal femur was composed of a proliferation of ovoid or fusiform cells arranged in fascicles with high mitotic activities. The malignant transformed tumour in the acetabulum was made up of pleomorphic tumour cells with atypical mitoses. In the tumour of the distal femur, both p53 and H-ras mutations were detected. Abnormal nuclear accumulation of p53 protein and c-myc expression were also revealed by immunohistochemistry. In both cases, the recurrent malignant tumour over-expressed MMP-9 and revealed a higher MIB-1-labelling index compared with the primary conventional giant-cell tumour.

CONCLUSIONS

Our results suggest that multiple oncogene or tumour suppressor gene mutations may play an important role during malignant transformation in conventional giant-cell tumours.

Endometrioid adenocarcinomas of the uterine corpus in women younger than 50 years of age can be divided into two distinct clinical and pathologic entities based on anatomic location

BACKGROUND

This study used the clinicopathologic profiles of Japanese women younger than 50 years of age with endometrial carcinoma to distinguish the clinicopathologic features of carcinomas of the lower uterine segment (LUS) from those of carcinomas of the corpus mucosa proper (CMP).

METHODS

Eighty-eight endometrial carcinomas in women younger than 50 years old (25.3%) were selected from our file of 348 Japanese women with endometrial carcinoma. Seventy-two were classified as carcinomas of the CMP and 16 carcinomas of the LUS. A tumor was judged to be a carcinoma of the LUS when it involved a continuous area ranging from the lower corpus to the upper cervix with or without intervention of a portion of uninvolved LUS.

RESULTS

The mean ages of women with carcinomas of the CMP and LUS were 41.2 and 39.0 years, respectively. In comparison to carcinomas of the LUS, carcinomas of the CMP were more strongly associated with reproductive risk factors including parity (P = 0.01) and polycystic ovary syndrome (P = 0.02). There was no significant difference in body mass index or the incidence of diabetes mellitus and hypertension between women presenting with carcinomas of the CMP and LUS. Histologically, carcinomas of the LUS more frequently showed a high-grade endometrioid tumor (P = 0.02) with deep myometrial invasion (P < 0.01) and were less associated with endometrial hyperplasia (P < 0.01) than those of the CMP.

CONCLUSIONS

Carcinomas of the LUS occurred predominantly in women younger than 50 years of age and had clinicopathologic features distinct from carcinomas of the CMP in women younger than 50 years of age.

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.

Solitary fibrous tumor in the mental region

Solitary fibrous tumor (SFT) is a rare, benign, soft tissue tumor that most commonly occurs in the pleura; however, it has recently been described in other sites of the body. To date, eight examples of oral SFT have been reported. This paper is a description of the first case of an SFT occurring as a soft tissue tumor in the mental region. Histologically, the tumor was composed predominantly of rather uniform spindle-shaped fibroblastic cells arranged in vague fascicles or in a haphazard fashion, intermingled with abundant collagen fibers. Immunohistochemically, the tumor cells were positive for CD34 and vimentin, and weakly positive for muscle actin and alpha-smooth muscle actin. The diagnosis of SFT may be difficult as this tumor shares a number of histological features with other soft tissue tumors. Awareness of its occurrence in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided.

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.

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.

The accumulation of angiostatin-like fragments in human prostate carcinoma

PURPOSE

Angiostatin, a potent inhibitor of angiogenesis and, hence, the growth of tumor cell metastasis, is generated by a proteolytic enzyme from plasminogen. However, its localization and specific enzymes have yet to be ascertained in human tissue.

EXPERIMENTAL DESIGN

To elucidate the generation and the localization of angiostatin in prostate carcinoma, we examined angiostatin generation in a panel of human prostate cancer cell lines and performed immunohistochemistry with the antibodies to angiostatin and prostate-specific antigen (PSA), a potent proteolytic enzyme of angiostatin in 55 cases of prostate carcinoma.

RESULTS

We demonstrated that the lysates of human prostate carcinoma cell lines could generate angiostatin-like fragments from purified human plasminogen but could not generate angiostatin in the absence of exogenous plasminogen. The fragmented proteins were reacted with the monoclonal antibody specific for plasminogen lysine-binding site 1 (LBS-1). Immunohistochemically, the intracytoplasmic immunostaining of LBS-1 was positive in 87.3% (48 of 55) of prostate carcinoma cases, and the immunostaining of miniplasminogen was negative in all cases. There was a significant relationship between the positive immunostaining of LBS-1 and Gleason score (P = 0.0007). The intracytoplasmic immunostaining of PSA was positive in 37.0% (20 of 54) of prostate carcinoma cases, but there was no significant relationship between the expression of PSA and Gleason score, or between the positive immunostaining of LBS-1 and PSA.

CONCLUSIONS

These findings suggest that angiostatin is generated by prostate carcinoma cells and is accumulated within the cytoplasm. In addition, the generation of angiostatin-like fragments was correlated with tumor grade; however, PSA may not be the only enzyme for angiostatin generation in human prostate carcinoma.

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.

Primary leiomyosarcoma of the patella

We report on a case of primary leiomyosarcoma of the patella in a 59-year-old woman. To our knowledge, this is the first report of this rare tumor in a bone where malignant lesions rarely occur.

Altered expression of beta-catenin without genetic mutation in intrahepatic cholangiocarcinoma

beta-catenin which has a role in E-cadherin mediated cell-to-cell adhesion, and is also involved in Wnt signaling pathways as a downstream signaling molecule accumulating in the cytoplasm and nucleus constitutively activates Tcf/LEF-associated transcription of oncogenic genes. We examined the expression pattern and the genetic alteration of beta-catenin to determine the role of beta-catenin in cancer formation and/or progression in intrahepatic cholangiocarcinoma (ICC). beta-catenin expression was immunohistochemically examined in 71 surgically resected ICC samples, and correlation between the expression pattern and clinicopathologic factors was investigated. Mutation analysis of beta-catenin exon 3, which included the responsible element for Wnt signaling was done in 55 samples, using PCR-SSCP and direct sequence methods. Immunohistochemical analysis revealed the reduced membranous expression of beta-catenin in 58 (82%) ICCs and aberrant nuclear expression in 11 (15%) ICCs. The membranous expression was preserved in 62% of the papillary adenocarcinomas, and was frequently reduced in tumors with a poorer histological differentiation (84%), with a significant difference (P =.01). Genetic analysis showed that none of the 55 ICCs examined carried mutations in beta-catenin exon 3. The present study indicates that reduced membranous expression of beta-catenin is associated with non-papillary ICCs which have a more malignant behavior, and that nuclear translocation of beta-catenin results in oncogenic events. Mutations in beta-catenin exon 3 do not appear to be responsible for nuclear translocation of beta-catenin in ICCs.

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.

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.

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.

Expression of a tumor-associated antigen RCAS1 in hepatocellular carcinoma

RCAS1 has been reported as a tumor-associated antigen in uterine and ovarian carcinomas. In vitro studies on RCAS1 indicated that it might function as an apoptosis-inducing factor since binding between RCAS1 and its receptor induced apoptosis in receptor-expressing cells. In this study, 68 surgically resected samples of hepatocellular carcinoma (HCC) were prepared and RCAS1 expression was examined immunohistochemically, because RCAS1 was also positive in all HCC cell lines tested. Clinical and pathological parameters were then compared between RCAS1-positive and -negative HCC cases. As a result, RCAS1 is expressed in 26.5% of HCC cases and vascular invasion is observed at a much higher rate in the RCAS1-positive cases (72.2%) than in RCAS1-negative cases (24.0%). RCAS1 is not an antigen specific for gynecological cancers. In HCC cases, the RCAS1-positive percentage is not high, however, RCAS1-positive HCCs exhibited a trend towards invasive character.