Clinical and biologic characteristics for recurring neuroblastoma at mass screening cases in Japan

BACKGROUND

It is said that most cases detected by neuroblastoma mass screening at 6 months of age tend to have a favorable clinical course after a surgical resection either with or without mild chemotherapy. However, a few cases have an unfavorable outcome. In the current study, the authors analyzed the clinical and biologic characteristics for recurring neuroblastoma in mass screening cases.

METHODS

In 245 cases detected through mass screening in the Kyushu area in Japan, the clinical data and biologic features (N-myc status, DNA ploidy, Shimada histology, neuron-specific enolase (NSE), ferritin) were investigated, whereas, in particular, the data for recurring cases also were analyzed.

RESULTS

Of 245 cases, 28 tumors had one or more biologically unfavorable prognostic factors, and 6 patients experienced recurrence. Three of the six patients with recurring disease underwent a complete resection of the primary tumor, whereas three cases had undergone an incomplete resection of the tumor. Regarding the initial chemotherapy, three cases received mild chemotherapy, two cases received no chemotherapy, and one case had high-dose multidrug chemotherapy. Regarding biologic prognostic factors, four of six cases with recurring disease had one or more unfavorable factors, whereas two cases had no unfavorable factors. Regarding the outcome after recurrence, four cases are CR, one case has a stable residual tumor, and one case died of disease with N-myc amplification.

CONCLUSIONS

Most neuroblastomas detected by mass screening at 6 months of age have biologically favorable factors. However, approximately 10% of the cases had one or more unfavorable factors and thus might have a higher risk of recurrence than the patients with no unfavorable factors. Conversely, some cases with recurring disease had no unfavorable factors; however, the reason for this is still unclear. A long-term follow-up for mass screening cases is important, and it also might be necessary to research the established biologic factors and identify other new prognostic factors.

Mutations of the p53 gene in malignant rhabdoid tumors of soft tissue and the kidney: immunohistochemical and DNA direct sequencing analysis

Malignant rhabdoid tumor (MRT) is characterized by the presence of intracytoplasmic eosinophilic inclusions composed of whorls of intermediate filaments. This tumor was originally described as an entity of the abortive type of Wilms' tumor in childhood. Recently, it has been proved that these rhabdoid cells can be observed in various types of malignant tumors, including soft tissue sarcoma or carcinoma. To investigate the oncogenesis of this tumor, we examined the p53 gene alteration by means of immunohistochemical analysis and DNA direct sequencing in three cases of malignant rhabdoid tumor (MRT) of the soft tissue and three cases of MRT of the kidney. All the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed immunopositivity for p53 protein. Among them, one of the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed missense mutations of the p53 gene. These results strongly suggest that p53 gene alterations may have an important role to play in the aggressive biological behavior and poor prognosis of this tumor.

The role of overexpression and gene amplification of cyclin D1 in intrahepatic cholangiocarcinoma

BACKGROUND/AIMS

Intrahepatic cholangiocarcinoma (ICC) is a primary liver malignant tumor with an extremely poor prognosis, but less attention has been directed to factors related to molecular carcinogenesis, including cell cycle proteins. We examined the expression and gene amplification of cyclin D1, the cell cycle regulating protein. Our objective was to evaluate correlations with clinicopathological factors in ICC.

METHODS

Cyclin D1 overexpression and cellular proliferative activity (Ki-67 labeling index) were investigated immunohistochemically, and 20 cases were further investigated for cyclin D1 gene amplification, using differential PCR. We examined the correlation between the expression and gene amplification of cyclin D1 and clinicopathological factors, including overall survival in patients with ICC.

RESULTS

Immunohistochemical analysis revealed an overexpression of cyclin D1 protein in 28 of 66 subjects with ICCs (42%). The cyclin D1 overexpression was associated with poor histological differentiation (P = 0.04), high cellular proliferative activity (P < 0.01), and a poor prognosis (P = 0.02) by univariate analysis, although it is not an independent prognostic factor by multivariate analysis. Cyclin D1 gene amplification was confirmed in five of the 20 patients. Of those five cases of ICC, all had poor histological differentiation, and four of the five ICCs (80%) showed evidence of cyclin D1 immunoreactivity.

CONCLUSIONS

Overexpression and gene amplification of cyclin D1 are frequent and contribute to dedifferentiation and cellular proliferative activity of ICCs, and overexpression also indicates a poor prognosis for patients with ICC.

Phenotypical characteristics of undifferentiated carcinoma of the pancreas: a comparison with pancreatic ductal adenocarcinoma and relevance of E-cadherin, alpha catenin and beta catenin expression

The characteristics of undifferentiated (anaplastic) carcinoma (UC) of the pancreas were analysed and compared with those of poorly differentiated adenocarcinoma (PA). Eight cases of UC of the pancreas were evaluated by clinicopathological and immunohistochemical methods and compared with 20 cases of PA. Large size of the tumor, local invasion and lymph node metastasis were frequently seen in UC, leading to a significantly worse prognosis compared to that of PA (p=0.022). Immunohistochemically, E-cadherin expression was completely lost in 7/8 UC cases, whereas half the PA cases revealed a strong reactivity for E-cadherin. alpha- and beta-catenin expressions tended to be impaired in UC compared with PA. The results suggest that the altered expression of adhesion molecules is correlated with dedifferentiated change and is contributory to its aggressive biological behaviour.

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.

Phenotypic expression of colorectal adenocarcinomas with reference to tumor development and biological behavior

The purpose of this study is to clarify the correlation between cell differentiation and tumor development, including tumor aggressiveness and biological behavior. Eighty-three cases of advanced colorectal adenocarcinoma were randomly selected. Using immunohistochemical staining with antibodies to CD10, MUC2 and human gastric mucin (HGM), the colorectal adenocarcinomas could be classified into five types (18 small intestinal, 27 large intestinal, 2 gastric, 9 mixed and 27 unclassified). Each type had characteristic features. The small-intestinal type showed a relatively lower incidence of lymphatic permeation and higher venous invasion. The large-intestinal type showed a low incidence of venous invasion and lymph node metastasis. The mixed type revealed female and right-side-dominant distribution, large tumor size, high incidence of mucinous carcinoma, and low incidence of venous invasion. Gastric type was seen in only two cases (2%), which exhibited high histologic grade, lymphatic permeation and lymph node metastasis with no venous invasion. Such phenotypic classifications are considered to be useful not only for evaluation of the biological behavior of the carcinoma, but also for analysis of tumorigenesis.

High expression of the Cap43 gene in infiltrating macrophages of human renal cell carcinomas

We used suppression subtractive hybridization to identify highly expressed genes in the cancerous region of human renal cell carcinoma (RCC) compared with noncancerous tissue. Nine genes were identified to show increased expression in the cancerous region compared with the noncancerous region. The nine genes included thymosin beta4, secreted protein acidic and rich in cysteine (SPARC), Cap43, ceruloplasmin, serum amyloid A, osteopontin, heat shock protein 90 (HSP90), LOT1, and casein kinase I. Of these 9 genes, in situ hybridization with 10 clinical samples consistently showed a strong expression of Cap43 mRNA in infiltrating macrophages in RCCs, but not in cancer cells proliferating in an alveolar pattern. However, Cap43 mRNA was also apparently detected in epithelial cells of the renal proximal tubuli in noncancerous tissue. The higher expression of the Cap43 gene in the cancerous region of RCCs appears to depend on macrophage infiltration. Moreover, treatment with phorbol ester resulted in enhanced expression of the Cap43 gene in human monocytic cells in vitro. The expression of the Cap43 gene in infiltrating macrophages is discussed in association with the differentiated or activated status of monocyte/macrophage.

Immunoexpression of ultraviolet photoproducts and p53 mutation analysis in atypical fibroxanthoma and superficial malignant fibrous histiocytoma

p53 mutation is one of the major results of ultraviolet (UV) radiation. UV photoproducts of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts (64PPs) also play an important role in skin cancer development. Atypical fibroxanthoma (AFX), which mimics malignant fibrous histiocytoma (MFH) histologically, occurs in the sun-exposed skin of the elderly, and therefore, an association with UV has long been suspected. Eighteen fibrohistiocytic skin lesions comprising AFX (n = 7), storiform-pleomorphic type MFH centered in the subcutis (superficial MFH; S-MFH; n = 4) and benign fibrous histiocytoma (BFH; n = 7) were used for immunohistochemical and molecular analysis. Eight cases of deep MFH (D-MFH) were also analyzed for UV photoproduct expression for the purposes of comparison. Immunohistochemically, the CPD scores of AFX (3.6 +/- 0.4) were significantly higher than those of S-MFH (1.3 +/- 0.8), D-MFH (0.8 +/- 0.5), or BHF (1.4 +/- 0.7); however, the 64PP scores were extremely low in all these tumors (AFX, 0.1 +/- 0.1; S-MFH, 0.0 +/- 0.0; D-MFH, 0.0 +/- 0.0; and BHF, 0.0 +/- 0.0). AFX, S-MFH, and BFH showed immunoexpression for p53 (2/7, 2/4, and 0/7), respectively. p53 mutations were detected in AFX (4/6; 67%) and S-MFH (1/4; 25%), but not in BFH (0/5; 0%) using polymerase chain reaction-single-strand conformation polymorphism, and all of the mutations in AFX were either C-T transitions or at dipyrimidine sites. In conclusion, AFX and S-MFH are both similar fibrohistocytic lesions; however, AFX has high immunoreactivity for CPDs compared with S-MFH, D-MFH, or BFH. These data suggest that CPDs may play an important role in the pathogenesis of AFX.

Cell proliferative activity and expression of cell-cell adhesion factors (E-cadherin, alpha-, beta-, and gamma-catenin, and p120) in sarcomatoid renal cell carcinoma

BACKGROUND AND OBJECTIVES

Sarcomatoid RCC (renal cell carcinoma) is an uncommon, but not rare, neoplasm which has been shown to have a much worse prognosis than common RCC. The current study was designed to investigate the association of proliferative activity and cell-cell adhesion molecules with sarcomatoid RCC.

METHODS

Proliferative activity (Ki-67 labeling index) and expression of cell-cell adhesion associated molecules (E-cadherin, alpha-, beta-, and gamma-catenin, and p120) were examined using immunohistochemical techniques in 11 cases of sarcomatoid RCC.

RESULTS

In six patients with sarcomatous component more than 50%, five were died within 24 month after diagnosis. The expression of these molecules within the carcinomatous and sarcomatous components of sarcomatoid RCC was compared. The mean Ki-67 labeling index in the sarcomatous components (12.6%) is statistically higher than in the carcinomatous components (3.7%) (P < 0.05). The expressions of E-cadherin, and alpha-, beta-, and gamma-catenin were statistically decreased in the sarcomatous components compared to the carcinomatous components. However, no differences were observed regarding p120 immunostaining.

CONCLUSIONS

The findings of the current study suggest that the range of the sarcomatous component may be a prognostic factor in RCC, and the malignant behavior of sarcomatoid RCC is due to high cell proliferative activity and decreased expressions of E-cadherin and alpha-, beta-, and gamma-catenin in the sarcomatous component.

The role of p27kip1 protein expression on the biological behavior of intrahepatic cholangiocarcinoma

Recent studies have reported that a decreased p27kip1 protein (p27) expression is associated with aggressive tumor behavior in several human malignancies. In this study, we examined the role of p27 expression in intrahepatic cholangiocarcinoma (ICC) and the noncancerous intrahepatic bile duct epithelium and assessed its association with clinicopathologic features, especially the influence of decreased p27 expression by the tumor on its prognosis as determined by immunohistochemistry. Almost all noncancerous bile duct epithelia show positive nuclear staining and reveal a faintly positive reaction in the cytoplasm. In 62 surgically resected ICCs, a variable degree of positive p27 nuclear staining is recognized. A subset (13 of 62 cases; 21.0%) of the carcinomas displayed cytoplasmic staining. We classified 62 cases into 2 groups, a low expression group (< 50% of p27 nuclear positive cells) and a high expression group (> or = 50% of p27 nuclear positive cells), and tested for the association between positive expression and clinicopathologic features. We found that a low expression of nuclear p27 was correlated with positive vascular invasion (P < .05). The survival curve of the group with low p27 nuclear expression was significantly lower than that of the group with high p27 nuclear expression (P < .005). According to the multivariate analyses, low p27 expression can be considered an independent prognostic factor whose occurrence indicates a worse prognosis. We conclude that a decreased p27 expression adds an independent parameter that can be used when determining the prognosis of patients with ICC.

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.

H-ras oncogene mutation in dedifferentiated chondrosarcoma: polymerase chain reaction-restriction fragment length polymorphism analysis

Dedifferentiated chondrosarcomas, which are known for their poor prognosis, are characterized by conventional chondrosarcoma with high-grade anaplastic components. Activating mutations in ras genes are a common genetic abnormality in human malignancies. The presence of point mutations at codons 12 and 13 of the H-ras gene was studied in 20 formalin-fixed paraffin-embedded chondrosarcomas, comprising 11 cases of conventional chondrosarcoma (six Grade 1 cases and five Grade 2 cases) and nine cases of dedifferentiated chondrosarcoma, using polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. H-ras mutations were only seen in two out of the nine cases of dedifferentiated chondrosarcoma (2/9, 22%) and they were not seen in any of the cases of conventional chondrosarcoma (0/11, 0%). Dedifferentiated chondrosarcomas had a worse prognosis than conventional chondrosarcomas (P < .01); among the patients with dedifferentiated chondrosarcomas, those with H-ras mutation (n = 2) tended to have a worse prognosis than those without (n = 7), although the difference was not statistically significant (P = 0.068). Our results would seem to suggest that H-ras mutation may occur during the course of dedifferentiation and may also have some effect on malignant potential.

Predictive value of endoscopic ultrasonography for regression of gastric low grade and high grade MALT lymphomas after eradication of Helicobacter pylori

BACKGROUND

While a close association between gastric mucosa associated lymphoid tissue (MALT) lymphoma and Helicobacter pylori infection has been established, there are still cases which do not respond to H pylori eradication.

AIMS

To investigate the clinicopathological factors which may help predict the therapeutic efficacy of H pylori eradication in gastric MALT lymphoma.

PATIENTS

Forty one patients with gastric MALT lymphoma, including low and high grade lesions.

METHODS

After endosonographic staging was determined, H pylori was eradicated in all patients, and the subsequent gastric pathological course was then investigated.

RESULTS

Complete regression of MALT lymphoma was observed in 29(71%) patients, partial regression in five (12%), and no regression in seven (17%). Twenty six (93%) of 28 MALT lymphomas restricted to the mucosa but only three (23%) of 13 lymphomas which invaded the deep portion of the submucosa or beyond completely regressed. Kaplan-Meier analysis for the probability of complete regression of MALT lymphoma revealed a significant difference between tumours restricted to the mucosa and those invading the submucosa deeply or beyond (p<0.05). Neither the presence of a high grade component, perigastric lymphadenopathy, nor clinical staging prior to eradication correlated with the probability of lymphoma regression.

CONCLUSIONS

Assessment of deep submucosal invasion by endosonography is valuable for predicting the efficacy of H pylori eradication in gastric MALT lymphoma.

Relative quantitation of p53 and MDM2 gene expression in leiomyosarcoma; real-time semi-quantitative reverse transcription-polymerase chain reaction

To investigate the etiology of leiomyosarcoma, we examined abnormalities of p53 and its regulation in 13 cases of leiomyosarcoma using fresh tumor specimens. We estimated p53 and MDM2 mRNA level and MDM2 gene amplification using a real-time semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) based on the TaqMan fluorescence method. We also used immunohistochemistry (IHC) for p53 and MDM2 protein overexpression, polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing to detect p53 mutation. Eight of the 13 cases (62%) showed an overexpression of p53 protein on IHC and eight of 13 cases (62%) had p53 gene point mutations. Five of the 13 cases (38%) showed positive staining for MDM2 protein and only one case (7.7%) demonstrated MDM2 gene amplification. The relative p53 mRNA level of the tumors compared with normal tissue ranged from 1.14 to 12.19 arbitrary units (AU), and the MDM2 mRNA level ranged from 1.06 to 17.17 AU. The mRNA level in the p53-positive cases was higher than in the negative cases (positive: 7.70 AU on average; negative: 3.38 AU on average; P=0.0344). However, there was no significant correlation between the MDM2 mRNA level and other factors, such as p53 IHC, p53 mutation status, p53 mRNA level and MDM2 IHC. Our results indicate that p53 abnormalities are major events and that an increasing level of p53 mRNA is associated with an overexpression of p53 protein in leiomyosarcoma and they may play an important role in the tumorigenesis in this tumor.

Glomangiopericytoma causing oncogenic osteomalacia. A case report with immunohistochemical analysis

A 47-year-old woman suffered from gait disturbance due to back pain and muscle weakness. Laboratory data showed serum hypophosphatemia, elevated alkaline phosphatase, and a normal level of ionized calcium. Radiological examinations revealed multiple pathologic fractures in the ribs and pubic rami. She had had no episode of familial or any other notable disorder, and so she was initially treated with medication for adult-onset osteomalacia. However, 19 years later (when she was 66 years old), she noticed a soft-tissue tumor in her buttock. The tumor was excised. The histological features were those of glomangiopericytoma characterized by both glomus tumor-like and hemangiopericytoma-like structures. After removal of the tumor, her symptoms disappeared immediately. Laboratory data normalized 8 months later. To our knowledge, this is the first report of oncogenic osteomalacia caused by glomangiopericytoma.

Low expression of p27(Kip1), a cyclin-dependent kinase inhibitor, is a marker of poor prognosis in synovial sarcoma

BACKGROUND

Low expression of p27(kip1), a dominant cyclin-dependent kinase inhibitor involved in G1-S transition of the cell cycle, recently has been reported to be associated with aggressive tumor growth. It has been shown that active cell proliferation alludes to poor prognosis in patients with synovial sarcoma. However, to the authors' knowledge, little is known about the clinicopathologic significance of p27(kip1) in synovial sarcoma.

METHODS

p27(kip1) expression was examined immunohistochemically in 55 cases of primary synovial sarcoma, and the relations between p27(kip1) expression and several cell proliferation markers, i.e., mitotic index (MI), Ki-67 labeling index (Ki-67 LI), and clinicopathologic parameters related to poor prognosis, were determined. Univariate and multivariate survival analyses were performed to evaluate the prognostic significance of p27(kip1) expression in synovial sarcomas.

RESULTS

p27(kip1) labeling index (p27(kip1) LI) correlated inversely with MI (r = -0.44, P = 0.0007) and Ki-67 LI (r = -0.63, P < 0.0001). Of the clinicopathologic parameters examined, tumor necrosis (P = 0.019) and American Joint Committee on Cancer (AJCC) stage (P = 0.021) correlated significantly with p27(kip1) LI. Survival analysis showed that p27(kip1) LI was an independent prognostic factor for overall survival in patients with synovial sarcoma (P = 0.0031).

CONCLUSIONS

The study results suggested that low expression of p27(kip1) may be useful as a marker of poor-prognosis synovial sarcoma.

H-ras oncogene mutation in dedifferentiated liposarcoma. Polymerase chain reaction-restriction fragment length polymorphism analysis

Point mutations of the ras gene family (K-ras, H-ras, and N-ras) are thought to be involved in the development of a variety of human tumors. Dedifferentiated liposarcoma is characterized by the coexistence of well-differentiated (WD) and high-grade anaplastic (HG) components. The presence of point mutations at codons 12 and 13 of the H-ras gene was studied in 34 liposarcomas, comprising 15 well-differentiated liposarcomas and 19 dedifferentiated liposarcomas, and in 8 storiform-pleomorphic type malignant fibrous histiocytomas (MFHs) using polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. The 2 components of dedifferentiated liposarcoma were analyzed independently. H-ras mutations were seen only in dedifferentiated liposarcomas (4/19 [21%]), 1 in WD components and 3 in HG components. The mutation was not seen in any of 15 cases of well-differentiated liposarcoma. MFHs showed an H-ras mutation in 1 (12%) of 8 cases. Our results seem to suggest that the H-ras mutation is a relatively uncommon event in dedifferentiated liposarcoma, which may demonstrate an epiphenomenon of dedifferentiation in dedifferentiated liposarcoma.

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.

Establishment and characterization of malignant rhabdoid tumor of the kidney

Malignant rhabdoid tumor of the kidney (MRTK) is a highly aggressive tumor which occurs in childhood and which is histologically characterized by the existence of eosinophilic intracytoplasmic inclusions. We established and characterized a cell line from this tumor with histological, immunohistochemical and cytogenetical analysis. Histologically, the tumor cells demonstrate typical eosinophilic inclusions, while immunohistochemically the cells demonstrate common mesenchymal and epithelial differentiation. Although the conventional karyotyping of this tumor lacked the abnormalities of 22q chromosome, Southern blot analysis and microsatellite analysis verified abnormalities of the BCR gene and of the hSNF5/INI1 gene. Despite the variety of locations, these common genetic abnormalities appear to contribute to distinguish rhabdoid tumor from such other small round cell tumors as primitive neuroectodermal tumor, rhabdomyosarcoma, poorly differentiated synovial sarcoma and desmoplastic small round cell tumor.

Different characteristics of carcinoma in the gastric remnant: histochemical and immunohistochemical studies

Seventy cases of cancer of the gastric remnant were divided into three groups: 33 cases following surgery for benign disease (group A), and 15 cases occurring more than 10 years and 22 cases occurring within 10 years after the first gastrectomy for malignant disease (groups B and C, respectively). Then mucin histochemical and immunohistochemical studies were undertaken. Billroth-II procedure for anastomosis was most frequently performed in group A. Intestinal metaplasia within the mucosa surrounding the carcinomas was more frequently present in groups A and C with a diffuse distribution. Intestinal-type surrounding mucosa was significantly more frequent in group C. The immunohistochemical expression of p53 protein was most frequently expressed in group B. We conclude that a different mechanism of carcinogenesis exists in these three groups; i) group A: the reflux of duodenal juice especially following B-II procedures leads to progression of the carcinoma. ii) group B: some genetic factor such as p53 may be related to the metachronous multiple carcinogenesis. iii) group C: metachronous multiple carcinogenesis within the short interval may be closely associated with diffuse intestinal metaplasia in the surrounding mucosa.

Gastric or intestinal phenotypic expression in the carcinomas and background mucosa of multiple early gastric carcinomas

AIMS

The differences in phenotypic expression between multiple early gastric carcinomas (EGCs) and solitary EGCs were evaluated in this study.

METHODS AND RESULTS

Fifty-three cases (53 lesions) of solitary EGCs and 50 cases (112 lesions) of multiple EGCs were studied. According to the classification of intestinal metaplasia, the phenotypes of carcinomas and background mucosa were classified into four categories-complete intestinal type, incomplete intestinal type, gastric type and unclassified type-based on the combination of expression of CD10 (small intestinal brush border), MUC2 (intestinal goblet cell), HGM (gastric foveolar epithelium) and Con A (gastric pyloric glands). The incidence of gastric-type carcinomas (48%) and the incidence of incomplete intestinal-type background mucosa (75%) among the multiple EGCs was higher than among the solitary EGCs. There was a significant difference in distribution of phenotypic expression of carcinomas and background mucosa between the solitary EGCs and the multiple EGCs, the latter being associated with incomplete intestinal metaplasia.

CONCLUSIONS

Both the carcinomas and the background mucosa of multiple EGCs have an unstable status, since they more commonly possess the hybrid phenotype of the stomach and the small intestine than does solitary EGC. Such instability is considered to contribute to a high neoplastic potential and the multiple occurrence of carcinomas.

Carcinoma of the ampulla of Vater associated with or without adenoma: a clinicopathologic analysis of 198 cases with reference to p53 and Ki-67 immunohistochemical expressions

Adenomatous areas are found frequently within or in the vicinity of carcinoma of the ampulla of Vater. This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is generally accepted for colorectal tumors. Recently, a genetic alteration model during colorectal tumor development has attracted much attention, leading to various studies. We studied clinicopathologic features, prognostic factors, and the alteration of the p53 tumor suppressor gene using p53 immunohistochemical staining in pure adenomas, pure carcinomas, and carcinomas with adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of the ampulla of Vater were selected for this study. Among the 198 cases of thecarcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immunohistochemical staining was 0% in pure adenomas, 36% in the adenomatous areas of carcinomas with adenomatous areas and 62% in the carcinomatous areas of carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulation of p53 protein and the Ki-67 labeling index revealed no significant difference in prognosis. The clinicopathological factors examined were as follows: degree of invasion of the surrounding tissue, such as duodenal wall; pancreatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metastasis; and TNM stage. Each of the clinicopathological factors showed a significant difference. Multivariate analysis revealed strong predictors for a worse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma--carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater occur relatively late during the oncogenetic process. Moreover, we think it may be useful to refer to the p53 overexpression in the diagnosis of ampullary tumors.

The characteristics of mediastinal neuroblastoma

The prognosis of mediastinal neuroblastoma has been reported to be better than for other neuroblastomas. The reason for this is however not clear. Furthermore, a comparison between mediastinal neuroblastoma and the other neuroblastomas has been rarely reported so far. In this study, the characteristics of mediastinal neuroblastoma (84 cases) are investigated and compared with those of other neuroblastomas (440 cases). Regarding clinical factors, the age distribution and the rate of cases detected at mass screening were similar in both groups. According to Evan's staging system, the rates of early stage (I, II) were 62% in the mediastinal neuroblastoma and 38% in the other neuroblastomas (p<0.001). Regarding the biological prognostic factors, a favorable histology based on Shimada's classification was found in 100% (35/35) of the mediastinal neuroblastoma cases and in 85% (112/132) of the other neuroblastoma cases (p<0.05). With regard to N-myc amplification, all of the examined 42 cases in mediastinal neuroblastoma had a N-copy number of less than 10 copies, while 32 of the examined 263 cases (12%) in the other neuroblastomas had an amplification of N-myc of more than 10 copies (p<0.05). The 5-year survival rates were 78% in the mediastinal neuroblastoma and 59% in the other neuroblastomas, respectively. Of the cases who underwent an incomplete resection of primary tumors in localized neuroblastoma, the 5-year survival rate of the mediastinal neuroblastoma cases was significantly more favorable than that of the other neuroblastomas. The majority of mediastinal neuroblastoma cases showed an early stage and favorable prognostic factors. It is likely that the clinical and biological prognostic factors of the tumor are therefore more closely correlated with the outcome of mediastinal neuroblastoma rather than the degree of the surgical resection. Regarding the treatment for mediastinal neuroblastoma, it is most important to evaluate the biology of the tumor after surgical resection.

Improved survival for patients with advanced neuroblastoma after high-dose combined chemotherapy based in part on N-myc amplification

BACKGROUND/PURPOSE

In spite of many different kinds of chemotherapy for neuroblastoma, the prognosis for advanced neuroblastoma remains unsatisfactory. In particular, the outcome of advanced neuroblastoma with high copies of the N-myc gene tend to be poor. Therefore, the new high-dosage combined chemotherapy regimens for advanced neuroblastoma based in part on the N-myc amplification status has been utilized in the Kyushu area of Japan since 1991. This study aims to investigate whether these new regimens based in part on N-myc amplification have improved the survival rate of stage III and stage IV patients in comparison with the old regimens.

METHODS

Between 1983 and 1995, 77 patients over 1 year of age and with stage III or IV neuroblastoma were registered in the Kyushu Area. Between 1983 and 1990, 49 patients received 1 of 2 combined chemotherapy regimens consisting of cyclophosphamide, cisplatin plus VM-26, and Adriamycin plus DTIC. Since 1991, two new regimens (New A1 and A3) have been administered based on the N-myc amplification status in a total of 28 patients. The New A1 regimen, which consists of cyclophosphamide, cisplatin, Adriamycin, and VP-16 has been administered in cases of less than 10 copies of N-myc, whereas the A3 regimen, consisting of a higher dose of cyclophosphamide, cisplatin, Adriamycin, and VP-16, has been administered in cases of more than 10 copies of N-myc. The survival rate was then compared between the old regimens and the new regimens.

RESULTS

The 3-year survival rate (61.5%) for patients treated by the new regimens was significantly higher than that (32.7%) for patients treated by the old regimens (P <.01). Regarding the 24 cases of more than 10 copies of N-myc, the 3-year survival rate (35.9%) of the 13 patients treated by the A3 regimen was higher than that (0%) of the 11 patients treated by the old regimens (P <.05). However, in the 19 stage IV patients treated by the new regimens, the 3-year survival rate (11.1%) of the 9 cases of more than 10 copies was significantly lower than that (77.8%) of the 10 cases of less than 10 copies of N-myc (P <.01).

CONCLUSIONS

These results suggest that high-dose combined chemotherapy based in part on the N-myc amplification status significantly improved the prognosis of patients with advanced neuroblastoma. However, stage IV patients with N-myc amplification still require a more effective treatment modality.

Rhabdoid features in leiomyosarcoma of soft tissue: with special reference to aggressive behavior

The presence of rhabdoid cells has been reported in various types of malignant neoplasms and has been determined to be a predictor of aggressive behavior of neoplasms regardless of tumor histogenesis. One hundred and thirteen cases of leiomyosarcoma, selected from 1800 soft tissue sarcomas, were reviewed on hematoxylin and eosin sections, and immunohistochemical staining when available, and seven cases with rhabdoid features were retrieved. Clinicopathologic differences were analyzed to compare between cases with rhabdoid features and those without rhabdoid features. In the seven cases with rhabdoid features, two were intra-abdominal, and the others arose in external soft tissues including muscle, subcutis, and cutis. Patient age ranged from 33 to 84 years, three were female, and four were male. Tumor size ranged from 3 to 22 cm. Clinical evidence showed no differences from those cases without rhabdoid features. Histologically, one of the abdominal cases was epithelioid leiomyosarcoma. Two of the 7 cases were better subclassified as pleomorphic leiomyosarcoma, in which rhabdoid cells are diffusely scattered. In cases other than those with pleomorphic leiomyosarcomas, foci of anaplastic areas were observed, and collections of rhabdoid cells were present in those areas. Immunohistochemical examination of the cases confirmed myogenic differentiation, and showed rhabdoid cells being positive for vimentin and desmin in the inclusion bodies, and diffusely so for muscle actin in the cytoplasm. After dividing all the cases of leiomyosarcoma by their location, prognostic analysis was performed. Leiomyosarcoma of external soft tissue with rhabdoid cells showed a tendency for poorer prognoses than cases without rhabdoid features. On the contrary, retroperitoneal cases did not. This study indicates that rhabdoid features are associated with aggressive biological behavior in leiomyosarcoma of the external soft tissue.

Prognostic value of the preserved expression of the E-cadherin and catenin families of adhesion molecules and of beta-catenin mutations in synovial sarcoma

This study addresses the immunohistochemical expression of the E-cadherin and catenin families and mutations of the beta-catenin gene detected by PCR-SSCP in synovial sarcoma. Immunohistochemical analysis was performed for 72 cases, with follow-up data available on 62. The prognostic value of the expression of these proteins was evaluated. Reduced immunoreactivity for E-cadherin and alpha-catenin was significantly correlated with a poor survival rate (p=0.0040 and 0.0053, respectively). According to multivariate analysis, low AJC stage (stages I and II: p<0.0001), the preservation of alpha-catenin expression (p=0.0001), and a low necrotic rate (<50%: p=0.0139) were independent favourable prognostic factors. Widespread aberrant staining of beta-catenin protein within cytoplasm and/or nuclei was observed in 28 cases (38.9%) and was significantly correlated with poor survival (p=0.0122). In addition, there was a trend towards a correlation between widespread aberrant staining of beta-catenin and the MIB-1 labelling index (p=0.0535). Mutational analysis of exon 3 of the beta-catenin gene was performed for 49 cases. Nucleotide sequencing analysis revealed that four (8.2%) contained point mutations (three in codon 32, GAC to TAC; one in codon 37, TCT to TTT). Survival data were available for three out of four cases with beta-catenin mutations; two of these patients died within 1 year (died of disease at 6 and 11 months, respectively). These results suggest that E-cadherin and alpha-catenin undertake important roles as intercellular adhesion molecules; their preserved expression is associated with a better overall survival rate in synovial sarcoma and may have prognostic value. Abnormal levels of beta-catenin, with or without mutation, could contribute to the development and progression of synovial sarcoma, through increasing the proliferative activity of the tumour cells.

Prognostic factors in ovarian carcinosarcoma: a clinicopathological and immunohistochemical analysis of 23 cases

Carcinosarcoma of the ovary is a rare, highly aggressive neoplasm comprising histologically of both epithelial and mesenchymal components. The aim of this study was to evaluate the clinicopathological prognostic factors in ovarian carcinosarcoma, including the immunohistochemical expression of p53 protein and Ki67.

METHODS AND RESULTS

Twenty-three cases of carcinosarcoma of the ovary were studied retrospectively. The clinicopathological and immunohistochemical parameters including p53 and Ki67 staining were statistically analysed to investigate the prognostic significance of this tumour. The overall 5-year survival rate was 27.1%; 100% for stage I, 31.3% for stage II, 10.9% for stage III and 0% for stage IV. The low-stage group (stages I and II) was found to be a significant prognostic factor for patient survival (P = 0.0113). None of the other factors (tumour size, histological type of carcinomatous and sarcomatous components, mitotic count, vascular space invasion and immunoreactivity for p53 protein and Ki6 7) was found to be a statistically significant prognostic indicator.

CONCLUSIONS

Ovarian carcinosarcoma is a rare malignancy with poor prognosis. In this study, advanced stage appears to be poor prognostic indicator of survival in patients with ovarian carcinosarcoma.

Molecular abnormalities of p53, MDM2, and H-ras in synovial sarcoma

Forty-nine cases of synovial sarcoma were evaluated for mutation of the p53 gene, amplification of the MDM2 gene and mutation of the H-ras gene, and for the relation of these factors to overall survival and clinicopathologic parameters. All investigations were carried out on formalin-fixed paraffin-embedded materials. Furthermore, we evaluated the expression of p53 protein, MDM2, and p21(WAF1/CIP1) immunohistochemically in these cases, together with an assessment of proliferative activities using monoclonal antibody MIB-1. Nine of the 49 cases (18.4%) had p53 gene alteration detected by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing. Eleven cases (24%) showed nuclear accumulation of p53 protein in more than 10% of the tumor cells. Among them, only three cases contained gene mutations. There was no correlation between p53 nuclear accumulation and p53 gene alteration. MDM2 gene amplification, as shown by differential PCR, was observed in 19 out of 47 cases (40%). Nineteen out of 49 cases (38.8%) showed immunoreactivity for MDM2. MDM2 gene amplification and the expression of MDM2 protein showed a significant positive relationship (P = 0.0004). Moreover, MDM2 immunoreaction was significantly correlated with nuclear accumulation of p53 protein (P = 0.023). Positive immunoreaction for p21(WAF1/CIP1) was observed in 21 out of 48 cases (43.8%). p21(WAF1/CIP1) expression was correlated with p53 protein expression. H-ras gene mutations were seen in only three cases (6.1%). All mutations were in codon 12 (one GGC-to-AGC [Gly-to-Ser] mutation and two GGC-to-GAC [Gly-to-Ap] mutations). The gene alteration of p53, MDM2, and H-ras did not affect the patients' prognosis. Although the cases with positive immunoreaction for p53 tended to have a worse prognosis, the difference was not statistically significant (P = 0.13). No correlation was observed between MIB-1 LI and the immunohistochemical expression of p53, MDM2, and p21(WAF1/CIP1) or the mutation status of p53 and H-ras. On the other hand, high MIB-1 LI (more than 10) significantly correlated with poor prognosis (P < 0.0001). Our results suggest that p53 gene mutation does not appear to be a major prognostic factor and H-ras mutations are infrequent in synovial sarcoma.

Prognostic significance of apoptosis in synovial sarcoma: correlation with clinicopathologic parameters, cell proliferative activity, and expression of apoptosis-related proteins

bcl-2 overexpression in synovial sarcomas has been recently reported. Although it is widely known that bcl-2 suppresses apoptosis in various cells, there are no studies that have examined the significance of apoptosis in synovial sarcoma. In the present study, we visualized apoptotic tumor cells by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end-labeling (TUNEL) method in 49 cases of primary synovial sarcoma. The degree of apoptosis was analyzed in relation to several clinicopathologic parameters, cell proliferative activity, and immunohistochemical expression of apoptosis-related proteins, including bcl-2, bax, bcl-x, bak, p53, p21 (WAF1/CIP1), Fas, and Fas ligand. TUNEL index (TUNEL-I) significantly correlated with the mitotic index (MI) (ñ = 0.60, P < .0001) and Ki-67 labeling index (MIB1-I) (ñ = 0.52, P = 0.0005). There was a highly significant association between high TUNEL-I value (>.8%) and poor prognosis (log-rank test; P < .0001). Many synovial sarcomas were diffusely positive for bcl-2 family proteins (bcl-2, bax, bcl-x, and bak) and were negative or only sporadically positive for Fas, Fas ligand, p53, and p21 (WAF1/CIP1) proteins. The results indicated that increased rate of apoptosis in primary synovial sarcoma was considered to be an indicator of poor prognosis. In addition, apoptosis in synovial sarcoma may be controlled by multiple apoptosis-regulating mechanisms, including the bcl-2 family.

Establishment of new multidrug-resistant human osteosarcoma cell lines

Multidrug-resistant clones of human osteosarcoma MNNG/HOS and MG63 cells were isolated by stepwise selection on exposure to increasing doses of doxorubicin (DXR). The final clones MNNG/HOS/DXR1000 and MG63/DXR1000, established after ethylmethane sulfonate mutagenesis, showed 96-fold and 121-fold higer resistance to DXR than their parental cell lines. They were also cross-resistant to vincristine, but not to cisplatinum or methotrexate. The levels of multidrug-resistance-1 (MDR1) mRNA expression increased gradually according to the concentration of DXR in both cell lines. Although the parental MNNG/HOS cells expressed a low level of MDR1 mRNA, the parental MG63 cells showed no MDR1 expression. The IC50 values of MNNG/HOS and its resistant variant to DXR were higher than those of MG63 and its resistant clone. Multidrug-resistant associated protein (MRP) mRNA expression was detected in MNNG/HOS or MG63 parental cell lines, and in their resistant variants. MG63 and its resistant variants revealed stable expression of MRP, whereas the resistant phenotype of MNNG/HOS showed decreased MRP expression, compared to its parental cell line. No alteration in the levels of hepatocyte growth factor (HGF) or its receptor c-MET was recognized between parental lines and their resistant variants. The results indicate that our DXR-resistant variants of MNNG/HOS and MG63 reveal a classical MDR phenotype and can offer a model with which to investigate the mechanisms of multidrug resistance in osteosarcoma.

Increased expression of an ATP-binding cassette superfamily transporter, multidrug resistance protein 2, in human colorectal carcinomas

The expression of ATP-binding cassette superfamily transporter genes, such as P-glycoprotein/multidrug resistance (MDR) 1 and MDR protein (MRP) 1, is often up-regulated in various tumor types and is involved in responses to some anticancer chemotherapeutic agents. Five human MRP subfamily members (MRP2-6) with structural similarities to MRP1 have been identified. The relationships between MRP2-6 mRNA levels and drug resistance are not well understood. Data on 45 patients with colorectal cancer were analyzed. Of the ATP-binding cassette superfamily genes, we asked whether mRNA levels of MDR1, MRP1, MRP2, and MRP3 correlated with drug resistance to anticancer agents. For this analysis, we used quantitative reverse transcription-PCR, and the sensitivity to anticancer agents in surgically resected colon carcinomas was determined using the in vitro succinate dehydrogenase inhibition test. MDR1, MRP1, and MRP3 were highly expressed in normal colorectal mucosa, and the relative mRNA levels of MDR1, MRP1, and MRP3 in cancerous tissues compared with noncancerous tissues were decreased or unchanged. By contrast, MRP2 mRNA expression was low in normal colorectal mucosa and specifically increased in cancer regions compared with noncancerous regions. Of the anticancer agents prescribed for patients with colorectal cancers, including doxorubicin, mitomycin C, cisplatin, 5-fluorouracil, etoposide, and a camptothecin derivative, mRNA expression of MRP2 was significantly associated with resistance to cisplatin. MRP2 may be important for resistance to cisplatin treatment in colorectal cancer.

Adhesion proteins, cellular morphology and fibrous components around the cell/extracellular-matrix interface in myxoid liposarcomas

We examined the cell/extracellular-matrix interface in 13 myxoid liposarcomas by determining the distribution of collagen and reticular fibers in the myxoid matrix, the presence of adhesion proteins and the morphological features of the cytoplasmic border. Adhesion proteins (fibronectin, integrin alpha3) and the cytoplasmic border were examined by immunofluorescence and a differential interference-contrast image analysis respectively. A network of reticular fibers and collagen fibers was present in the myxoid matrix of 11 cases (85%) and 3 cases (23%) respectively. Tumor cells with dendritic cytoplasmic processes were observed in 8 cases (62%). Adhesion proteins were sparsely present in tumor cells and there was no correlation between those proteins and collagen fibers, reticular fibers or cytoplasmic processes. Collagen fibers, dense reticular fibers or well-developed cytoplasmic processes were more frequently observed in the cases of long-term-surviving patients than those with recently developed tumors or patients who died. All 3 cases positive for collagen fibers also contained both dense reticular fibers and cytoplasmic processes. Our findings suggest that the fibrous components in the myxoid matrix and the well-developed cytoplasmic processes may limit the invasiveness of malignant cells. This peculiar architecture may also explain the slowly progressive nature of myxoid liposarcomas.

H-ras-1 point mutation in malignant peripheral nerve sheath tumors: polymerase chain reaction restriction fragment length polymorphism analysis and direct sequencing from paraffin-embedded tissues

It has been shown that the NF1 (neurofibromatosis type 1) gene encodes a tumor suppressor which inactivates ras proteins. Among malignant mesenchymal tumors, H-ras-1 mutations have been found in malignant fibrous histiocytoma, leiomyosarcoma and embryonal rhabdomyosarcoma. However, studies on H-ras-1 mutation of many cases of malignant peripheral nerve sheath tumors (MPNST) have not been documented. Therefore, we investigated H-ras-1 mutations of MPNST. In 45 cases of MPNSTs of our files, DNA was extracted from the formalin-fixed paraffin-embedded tissue, and the mutations of the H-ras-1 gene were detected by using PCR-RFLP (polymerase chain reaction- restriction fragment length polymorphisms) method and direct sequencing. We found two cases with H-ras-1 point mutation in MPNST for the first time. Both cases showed the same mutation in codon 13.1 [GGT(Gly) to AGT(Ser) transition]. Interestingly, both cases were associated with NF1. It is possibile that the mutation of the H-ras-1 gene occurred after the mutation of the NF1 gene in the MPNST.

Natural history of ampullary adenoma in familial adenomatous polyposis: reconfirmation of benign nature during extended surveillance

OBJECTIVE

Surgical or endoscopic papillectomy may be one of the therapeutic strategies for patients with familial adenomatous polyposis (FAP). To determine whether prophylactic papillectomy is necessary for FAP, we investigated the natural history of the ampullary adenoma in FAP.

METHODS

Eighteen subjects with FAP were surveyed by duodenoscopy with biopsy for >10 yr. Endoscopic appearance, histological findings, and immunohistochemical stainings for Ki-67 of ampulla were compared between initial and final endoscopic examinations.

RESULTS

The endoscopic grade in the ampulla remained unchanged in 16 subjects, whereas in two subjects an increase in the endoscopic grade was noted. In two subjects adenoma developed from an endoscopically and histologically normal ampulla. The histological grade of dysplasia increased in three of 12 subjects who initially had adenoma. The labeling index for Ki-67 was not different between initial and final examinations.

CONCLUSIONS

These data suggest that most ampullary adenoma of patients with FAP is static and that aggressive endoscopic or surgical removal is unnecessary for the adenoma.

Comparison of histological changes and changes in nm23 and c-MET expression between primary and metastatic sites in osteosarcoma: a clinicopathologic and immunohistochemical study

Changes in morphological features between the primary and metastatic sites in osteosarcoma and the role of nm23 protein and c-MET oncogene product have remained controversial. In addition to histological studies, we evaluated the expression of nm23, c-MET, p53, and MDM2 immunohistochemically using 25 osteosarcomas in which both primary and concordant metastatic specimens were available. Moreover, we assessed proliferative activity using the monoclonal antibody MIB-1. Among these 25 cases, 4 tumors that were osteoblastic type (16%) in the primary site had changed morphologically to MFH-like type in the metastatic site, whereas 2 MFH-like type and 1 small cell-type tumors had changed to osteoblastic type. MIB-1 LI was significantly higher in the metastatic site than in the primary site (primary, 20.02; metastatic, 26.72; P = .0209). Seventeen cases (68%) showed increased nm23 expression in the metastatic site, whereas 2 cases showed reduced expression. nm23 expression was significantly increased in the metastatic site, compared with the primary site (P = .0009). Seven cases (28%) showing negative reaction for c-MET in the primary site showed immunuoreactivity for c-MET in the metastatic site. Although there was no statistical significance, c-MET expression seemed to be more frequent in the metastatic site, compared with the primary site. Among the overall tumors, c-MET-positive tumors showed significantly higher MIB-1 LI, compared with c-MET-negative tumors (negative, 20.99; positive, 27.65; P = .0292). No significant change was observed regarding p53 and MDM2 between the primary and metastatic site. Our results suggest that rather than being a metastasis-suppressor gene, nm23 is in fact correlated with metastatic progression in osteosarcoma. Positive correlation between c-MET expression and proliferative activity also suggests that c-MET expression may play an important role in tumor progression in osteosarcomas.

A comparative study of fibrous dysplasia and osteofibrous dysplasia with regard to Gsalpha mutation at the Arg201 codon: polymerase chain reaction-restriction fragment length polymorphism analysis of paraffin-embedded tissues

Fibrous dysplasia and osteofibrous dysplasia are both benign fibro-osseous lesions of the bone and are generally seen during childhood or adolescence. Histologically, the features of these bone lesions sometimes look quite similar, but their precise nature remains controversial. Mutation of the alpha subunit of signal-transducing G proteins (Gsalpha), with an increase in cyclic adenosine monophosphate (cAMP) formation, has been implicated in the development of multiple endocrinopathies of the Albright-McCune syndrome and in the development of fibrous dysplasia. We studied Gsalpha mutation at the Arg201. codon in seven cases of fibrous dysplasia (six monostotic lesions and one polyostotic lesion) and seven cases of osteofibrous dysplasia using formalin-fixed, paraffin-embedded tissue, by means of polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. All of the seven cases of fibrous dysplasia showed missense point mutations in Gsalpha at the Arg201 codon that resulted in Arg-to-His substitution in three cases and Arg-to-Cys substitution in four cases. On the other hand, the seven cases of osteofibrous dysplasia and the normal bone used as a control showed no such mutation. These data suggest that fibrous dysplasia and osteofibrous dysplasia have different pathogeneses and that the detection of Gsalpha mutation at the Arg201 codon is quite useful for distinguishing between these lesions.

'Serrated' adenoma of the colorectum, with reference to its gastric differentiation and its malignant potential

Serrated adenoma of the colorectum was a newly proposed entity in 1990, characterized by epithelial neoplasia combining the architectural features of a hyperplastic (metaplastic) polyp with the cytological features of an adenoma. Its histogenesis and natural history still remain unclear. Forty-six serrated adenomas were obtained from 46 patients. The clinicopathological features were summarized. Paraffin-embedded blocks from 34 serrated adenomas were available for immunohistochemical studies using pS2, human gastric mucin, and p53 protein. Eighteen hyperplastic (metaplastic) polyps, 16 tubular adenomas, and 12 early-stage adenocarcinomas were randomly selected as control groups for immunohistochemical analysis. The patients' ages ranged from 32 to 86 (average 61.4) years. Males were more frequently affected than females. Serrated adenomas were predominantly present in the left-side of the colon and in the rectum (72 per cent). Their sizes ranged from 3 to 26 mm (average 9. 2mm). Six lesions (13 per cent) contained foci of high-grade dysplasia. These adenomas were significantly larger (12.7 mm) than those containing no high-grade dysplasia (8.6mm). pS2 and human gastric mucin were expressed significantly more frequently in both hyperplastic (metaplastic) polyps and serrated adenomas than in tubular adenomas or adenocarcinomas. p53-positive cells were present in 18 of the 29 pure serrated adenomas (62 per cent) and in one of the five areas of low-grade dysplasia in serrated adenomas with high-grade dysplasia (20 per cent), most of which revealed a sporadic distribution. Only five of the 29 serated adenomas with no high-grade dysplasia (17 per cent) were regarded as demonstrating p53 overexpression. On the other hand, three of the five areas of high-grade dysplasia in serrated adenomas (60 per cent) revealed diffuse positivity (3+) for p53 protein. The serrated adenoma, which possibly shows gastric differentiation, is considered to be an independent histological entity among the various phenotypes of colorectal adenomas. Serrated adenoma would seem to be a precursor of carcinoma, its potential for malignant transformation being similar to that of the traditional tubular adenoma. It would also seem that p53 is involved in the serrated adenoma-carcinoma sequence.

Multiple 'serrated adenocarcinomas' of the colon with a cell lineage common to metaplastic polyp and serrated adenoma. Case report of a new subtype of colonic adenocarcinoma with gastric differentiation

A 70-year-old woman underwent right hemicolectomy and six carcinomas were recognized in the resected colon. These carcinomas were considered to be of a cell lineage common to serrated adenoma (SA) and hyperplastic (metaplastic) polyp (H/MP), because of the occurrence of multiple SAs and H/MPs around the carcinomas, as well as the co-existence of SA and H/MP areas within the carcinomas. These carcinomas had the following common histological and immunohistochemical features: a serrated structure resembling SA; a lace-like structure; infiltrative growth within the muscularis propria, with dedifferentiation at the invasive front; and immunohistochemical expression of pS2 and human gastric mucin. Based on these features, a new subtype of carcinoma is proposed, with a cell lineage common to SA and H/MP. It would also seem that p53 is involved in the serrated adenoma-carcinoma sequence.

Clinicopathological characteristics of surgically resected minute hepatocellular carcinomas

BACKGROUND/AIMS

The multistep development of overt hepatocellular carcinoma from very well-differentiated early hepatocellular carcinoma, and of early hepatocellular carcinoma from adenomatous hyperplasia has been strongly suggested. The clinicopathologic and immunohistochemical characteristics of solitary minute hepatocellular carcinomas smaller than 1 cm in size have yet to be clarified.

METHODOLOGY

Fourteen minute hepatocellular carcinomas were divided into 2 groups consisting of: 1) hepatocellular carcinoma of hepatitis B surface antigen positive patients (B-HCC) (n = 5), and 2) hepatocellular carcinoma of hepatitis C virus antibody positive patients (C-HCC) (n = 9), then they were all analyzed histopathologically and clinicopathologically. Immunohistochemical studies were also performed using the antibodies against p53 protein.

RESULTS

Six of the 14 minute hepatocellular carcinoma were demonstrated to be moderately or poorly differentiated tumors. Among the 8 well-differentiated minute hepatocellular carcinomas, 2 tumors already contained less differentiated components. B-HCC tended to be less differentiated than C-HCC (P < 0.05). Adenomatous hyperplasia was detected in only 2 cases of C-HCC. Small cell liver dysplasia was detected significantly more frequently in C-HCC than in B-HCC (P < 0.05). The prognosis of the 14 minute hepatocellular carcinomas varied considerably. Immunohistochemically, some tumor cells were positive for p53 in 3 cases.

CONCLUSIONS

Our study suggests that 1) the multistep carcinogenesis through adenomatous hyperplasia may not be so frequent, 2) De novo carcinogenesis from not only well-differentiated hepatocellular carcinoma, but also from less differentiated hepatocellular carcinoma, especially B-HCC, may be present, 3) the carcinogenesis in the B-HCC cases may behave differently from that in C-HCC cases, and 4) minute hepatocellular carcinomas demonstrate varying prognoses after hepatectomy.

Expressions of cell-cycle regulatory gene products in conventional gastric adenomas: possible immunohistochemical markers of malignant transformation

In 54 lesions of gastric adenomas consisting of 31 low-grade adenomas (LGAs) and 23 high-grade adenomas (HGAs), 28 intramucosal carcinomas (IMCs), and 23 carcinomas invading the submucosa (SMCs), the expression of cell-cycle regulatory gene products (p53, p21/waf1, p27/kip1, and Ki-67) was studied using immunohistochemical techniques. Several lesions were also analyzed by the fluorescence in situ hybridization method. The overexpression of p53 was found in no LGAs and in 9% of HGAs, whereas a considerable number of cases showed an overexpression in IMCs (39%) and SMCs (43%). A reduced expression of p21/waf1 was present in only 4% of HGAs. Superficial eccentric positivity was present in all LGAs and 74% of HGAs, whereas it was present in 46% of IMCs and 4% of SMCs. P53-positive and p21/waf1-negative lesions, which were supposed to have a mutated p53 gene, were observed in no LGAs, in 4% of HGAs, in 11% of IMCs, and in 26% of SMCs. The expression of cyclin E was more frequently present in carcinomas than in adenomas. However, no high expression of cyclin E was observed among the adenomas. A reduced expression of p27/kip1 was encountered more frequently in carcinoma than adenoma. By a semiquantitative evaluation comparing adenoma and carcinoma in the same stomach, the increased degrees of both p21/waf1 and cyclin E were highlighted. A chromosome gain was detected among 7% of the adenomas and 85% of the carcinomas. In conclusion, the expressions of p53, p21/waf1, p27/kip1, and cyclin E were considered to be of great value for estimating the dysplastic progression of gastric adenomas. Especially, various aspects of protein expression, including its distribution and semiquantitative evaluation of positive cells, and a combined analysis with several proteins, may thus be useful as possible markers of dysplastic evolution in gastric adenomas.

A clinicopathologic study of primary small intestine lymphoma: prognostic significance of mucosa-associated lymphoid tissue-derived lymphoma

BACKGROUND

It remains unclear whether the presence of mucosa-associated lymphoid tissue (MALT) lymphoma has prognostic implications for patients with primary small intestine lymphoma.

METHODS

The clinicopathologic features of 80 patients with primary small intestine lymphoma were examined retrospectively in relation to the presence of MALT lymphoma. Survival was compared univariately and multivariately among the groups divided by clinicopathologic findings.

RESULTS

Twenty-one cases (26%) were diagnosed as low grade B-cell lymphoma (15 marginal zone B-cell lymphoma of MALT type, 2 mantle cell lymphoma, and 4 follicle center lymphoma), 46 cases (58%) were diagnosed as high grade B-cell lymphoma (19 secondary large cell lymphoma with a low grade MALT component, 17 diffuse large cell lymphoma without MALT features, 7 Burkitt lymphoma, and 3 lymphoblastic lymphoma), and 13 cases (16%) were diagnosed as T-cell lymphoma. A significantly better survival was noted for patients without colorectal and/or gastric involvement, diffuse infiltration under macroscopy, high grade histology, and perforation. Those patients with MALT type tumors, less advanced stage of disease, B-cell phenotype, benign lymphoid follicular hyperplasia, and radical tumor resectability appeared to have a better survival rate. Based on Cox multivariate analysis, early stage disease and MALT-derived tumors were determined to be independent prognostic factors (P < 0.05).

CONCLUSIONS

The presence of MALT-derived lymphoma appears to have a favorable prognosis among patients with primary small intestinal lymphoma.

Discordance of p53 mutations of synchronous colorectal carcinomas

It is unclear whether synchronous multiple tumors arise from multicentric or monoclonal origins. To verify the multicentric origin of synchronous colorectal carcinomas at a genetic level, immunohistochemical and molecular techniques were used to determine the p53 alterations in individual lesions of synchronous colorectal carcinomas. This study was based on a total of 32 colorectal tumors from 16 patients. Twenty-one of the 32 (66%) advanced tumors examined had positive staining for p53. Single-strand conformation polymorphism and polymerase chain reaction direct sequencing were carried out for exons 5 to 8 of p53. All cases had p53 mutations in one or more tumors of synchronous lesions. In nine patients in this series, individual lesions were found to carry a different mutated codon of the p53 gene. In the other seven patients, a p53 mutation was found in one tumor but not in another. These results indicate discordance of the mutation pattern of p53 in individual lesions of multiple colorectal carcinomas and support the idea that most synchronous colorectal carcinomas are genetically distinguishable and are multicentric in origin. We also confirmed the high frequency of p53 mutations in left-sided (71%) and rectal (91%) carcinomas, rather than right-sided (43%; P = .04) carcinomas, suggesting that the molecular mechanism of synchronous colorectal carcinomas might differ between right- and left-sided tumors in the same patient.

Expression of hepatocyte growth factor (HGF)/scatter factor and its receptor c-MET correlates with poor prognosis in synovial sarcoma

The hepatocyte growth factor (HGF)/c-MET signaling system plays an important role in the carcinogenesis of various organs. We investigated the expression of HGF and its receptor c-MET by immunohistochemistry (IHC) in 69 cases of synovial sarcoma and compared the findings with clinicopathologic parameters, proliferating activities evaluated by MIB-1 labeling index (MIB-1 LI), and patients' prognosis. Furthermore, mRNA analysis of HGF, c-MET, and SYT-SSX fusion gene was performed by reverse transcriptase-polymerase chain reaction (RT-PCR) in 22 concordant frozen materials. Twenty-one of 69 (30.4%) tumors showed positive reaction for c-MET, whereas 22 tumors (31.9%) were positive for HGF. In 10 cases, co-expression of HGF and c-MET was observed; however, there was no significant correlation between HGF and c-MET expression. HGF expression was correlated with female patients, large tumors (more than 5 cm), the presence of rhabdoid cells, low frequency of mast cells (<20/10 HPF), high nuclear grade (grade III), and high American Joint Committee (AJC) stage (III and IV). Conversely, c-MET expression was only correlated with large tumors. However, the coexpression of HGF and c-MET was significantly correlated with large tumor size, the existence of rhabdoid cells, and high AJC stage. Both the expression of HGF and the co-expression of HGF and c-MET showed a significantly high MIB-1 LI and were correlated with poor prognosis according to univariate analysis. Multivariate Cox analysis showed that high AJC stage, the expression of HGF, and a high MIB-1 LI (12.0>) independently had a negative impact on overall survival. In 22 frozen material cases evaluated by both IHC and RT-PCR, a statistically significant correlation was found between the 2 techniques. SYT-SSX fusion transcripts were detected in all 22 cases. Three tumors had SYT-SSX2 fusion transcripts, whereas 19 had SYT-SSX1 phenotype. Our results suggest that HGF/c-MET paracrine signaling may contribute to tumorigenesis and progression in synovial sarcoma.

A clinicopathologic study of primary small intestine lymphoma: prognostic significance of mucosa-associated lymphoid tissue-derived lymphoma

BACKGROUND

It remains unclear whether the presence of mucosa-associated lymphoid tissue (MALT) lymphoma has prognostic implications for patients with primary small intestine lymphoma.

METHODS

The clinicopathologic features of 80 patients with primary small intestine lymphoma were examined retrospectively in relation to the presence of MALT lymphoma. Survival was compared univariately and multivariately among the groups divided by clinicopathologic findings.

RESULTS

Twenty-one cases (26%) were diagnosed as low grade B-cell lymphoma (15 marginal zone B-cell lymphoma of MALT type, 2 mantle cell lymphoma, and 4 follicle center lymphoma), 46 cases (58%) were diagnosed as high grade B-cell lymphoma (19 secondary large cell lymphoma with a low grade MALT component, 17 diffuse large cell lymphoma without MALT features, 7 Burkitt lymphoma, and 3 lymphoblastic lymphoma), and 13 cases (16%) were diagnosed as T-cell lymphoma. A significantly better survival was noted for patients without colorectal and/or gastric involvement, diffuse infiltration under macroscopy, high grade histology, and perforation. Those patients with MALT type tumors, less advanced stage of disease, B-cell phenotype, benign lymphoid follicular hyperplasia, and radical tumor resectability appeared to have a better survival rate. Based on Cox multivariate analysis, early stage disease and MALT-derived tumors were determined to be independent prognostic factors (P < 0.05).

CONCLUSIONS

The presence of MALT-derived lymphoma appears to have a favorable prognosis among patients with primary small intestinal lymphoma.

Evaluation of Epstein-Barr virus infection in sinonasal small round cell tumors

Sinonasal undifferentiated carcinoma, olfactory neuroblastoma and malignant melanoma of the sinonasal regions are included within the category of small round cell tumors of the sinonasal region. It is difficult to diagnose these tumors on the basis of light-microscopic features alone, but, in some instances, immunohistochemical staining evaluating cytokeratin and S-100 protein, for example, is of value. On the other hand, the sinonasal region is a significant site for Epstein-Barr-virus (EBV)-related tumors, including sinonasal undifferentiated carcinoma or malignant lymphoma. Twenty-three sinonasal small round cell tumors (SSRCT) comprising 5 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas and 9 malignant melanomas were evaluated for the presence of EBV infection by in situ hybridization for EBV-encoded RNA, combined with immunostaining for EBV-related proteins (LMP-1 and EBNA2). Furthermore, 55 SSRCT comprising 37 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas, and 9 malignant melanomas were examined for the presence of cytokeratins (AE1/ AE3 and CAM5.2), S-100 protein and p53 protein using immunohistochemical staining. According to in situ hybridization for detecting EBV-encoded RNA 1 (EBER1), all of the sinonasal undifferentiated carcinomas showed clear, intense hybridization signals localized over the nuclei of the tumor cells and, in 3 out of 9 (33.3%) malignant melanomas, hybridization signals were also recognized. However, none of the olfactory neuroblastomas revealed hybridization signals. Immunohistochemically, 4 out of 5 (80%) sinonasal undifferentiated carcinomas were positive for LMP-1, whereas only 2 out 9 (22.2%) malignant melanomas and no olfactory neuroblastomas were positive. With regard to EBNA2, sinonasal undifferentiated carcinomas, malignant melanomas and olfactory neuroblastomas were all negative. Out of 37 sinonasal undifferentiated carcinomas 35 (94.6%) showed a diffuse positive immunoreaction for AE1/AE3, whereas neither olfactory neuroblastoma nor malignant melanoma revealed a positive reaction. All 9 malignant melanomas and 6 out of 9 olfactory neuroblastomas (75%) were positive for S-100 protein, whereas only 6 cases of sinonasal undifferentiated carcinomas (19.4%) were positive. As for p53 protein, 16 of 37 sinonasal undifferentiated carcinomas (43.2%) were positive, whereas neither olfactory neuroblastoma nor malignant melanoma revealed any positive reaction. The above results suggest that EBV infection is closely associated with sinonasal undifferentiated carcinomas, and that some malignant melanomas may also have a relationship with its infection. For the differential diagnosis of SSRCT, it is important to evaluate EBV infection along with immunohistochemical staining for cytokeratins and S-100 protein. The overexpression of p53 protein was found to be related to the oncogenesis of sinonasal undifferentiated carcinoma; however, there was no association between its overexpression and malignant melanoma or olfactory neuroblastoma.

A comparative study of fibrous dysplasia and osteofibrous dysplasia with regard to expressions of c-fos and c-jun products and bone matrix proteins: a clinicopathologic review and immunohistochemical study of c-fos, c-jun, type I collagen, osteonectin, osteopontin, and osteocalcin

Fibrous dysplasia and osteofibrous dysplasia are both benign fibro-osseous lesions of the bone and are generally seen during childhood or adolescence. Histologically, the features of these bone lesions sometimes look quite similar, but their precise nature remains controversial. We retrospectively studied clinicopathologic findings in 62 cases of fibrous dysplasia and 20 cases of osteofibrous dysplasia with regard to their anatomic location and histological appearance. From among these cases, the immunohistochemical expressions of c-fos and c-jun proto-oncogene products and bone matrix proteins of type I collagen, osteonectin, osteopontin, and osteocalcin were evaluated in 20 typical fibrous dysplasias and 17 osteofibrous dysplasias using paraffin sections, and these expressions were then assessed semiquantitatively. Microscopically, fibrous dysplasia showed various secondary changes, such as hyalinization, hemorrhage, xanthomatous reaction, and cystic change in 22 of the 62 cases (35%). This was a higher incidence than in osteofibrous dysplasia, in which only 2 of the 20 cases (10%) showed such changes. In the elderly fibrous dysplasia cases, the cellularity of fibroblast-like cells was rather low, and those cases were hyalinized. Almost all of the cases of fibrous dysplasia and osteofibrous dysplasia showed positive expressions of c-fos and c-jun products. The expressions of type I collagen and osteopontin showed no difference between fibrous dysplasia and osteofibrous dysplasia. Immunoreactivity for osteonectin in bone matrix was detected in only 1 case of fibrous dysplasia (1 of 20), whereas it was recognized in 14 of the 17 cases of osteofibrous dysplasia. Furthermore, the immunoreactivity for osteocalcin in bone matrix and fibroblast-like cells was higher in fibrous dysplasia than it was in osteofibrous dysplasia, semiquantitatively. Our immunohistochemical results regarding osteonectin and osteocalcin suggest that the bone matrix of fibrous dysplasia is somewhat more mature than that of osteofibrous dysplasia, and that the fibroblast-like cells in fibrous dysplasia share some phenotypic features with osteoprogenitor cells of normal osteogenic tissues. Fibrous dysplasia and osteofibrous dysplasia share some similar histological features, including c-fos and c-jun expressions, although different clinicohistologic features and immunohistochemical expressions of osteonectin and osteocalcin were observed. These features suggest that the mechanisms behind the development of fibrous dysplasia and osteofibrous dysplasia are similar, but this is not necessarily indicative of a closer relationship between the 2 diseases.