Shigetaka Yamasaki

Tokyo Rinkai Hospital, Edo, Tōkyō, Japan

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Publications (21)42.59 Total impact

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    ABSTRACT: Cotyledonoid dissecting leiomyoma (Sternberg tumor) is a rare variant of the uterine smooth muscle tumor. Although this tumor is a benign tumor clinically and pathologically, the appearance and growth pattern is unusual, so it may be misdiagnosed as malignancy.
    Archives of Gynecology and Obstetrics 08/2014; · 1.33 Impact Factor
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    ABSTRACT: Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare inflammatory tumor-like lesion composed of vascular nodules and non-neoplastic stroma including spindle cells and inflammatory cells. The focus of our study was on the stromal proliferating process in SANT. Nine cases of SANT were examined. All cases showed alpha-smooth muscle actin (alpha-SMA) and vimentin on the spindle cells but not CD21, CD31, CD34, CD68, desmin, S100, human herpes virus-8, or anaplastic lymphoma kinase-1. In one case, 20-30% of the myofibroblasts in Epstein-Barr-virus (EBV)-positive spindle cells were detected using double-labeling immunohistochemistry for alpha-SMA and EBV-encoded small RNA in situ hybridization. A quantitative analysis of IgG and IgG4-positive plasma cells (pPCs) in SANT was performed. The median densities of IgG-pPCs and IgG4-pPCs in SANT were approximately four-fold and 13-fold higher than those in the normal spleens, respectively. In addition, there was a statistically significant increase of IgG4/IgG-pPCs ratio in SANT in comparison to the control specimens. In conclusion, the fibrogenesis in a subset of SANT may be associated with EBV-infected myofibroblasts in an overlapping immune reaction indicated by the presence of infiltrating IgG4-pPCs. Further investigation is needed to elucidate the association between SANT and IgG4-related sclerosing disease.
    Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 09/2008; 453(3):275-82. · 2.68 Impact Factor
  • Pathology International 07/2007; 57(6):388-9. · 1.72 Impact Factor
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    ABSTRACT: To examine aberrations and differences of cell cycle regulatory proteins between intraductal papillary-mucinous neoplasms (IPMNs) and pancreatic intraepithelial neoplasias (PanINs). In total, 47 IPMN lesions and 42 PanIN lesions were obtained from 26 patients with IPMN and 16 patients who underwent pancreatic surgery for invasive pancreatic ductal cancer or other diseases. They were subjected to conventional hematoxylin-eosin staining and immunostaining for p16INK4A and p53. The percentages of immunohistochemical positivity or negativity were compared between IPMN and PanIN, in accordance with the same histological grade of atypia. The Ki-67 labeling index was also counted in each lesion. Either the loss of p16INK4A expression or the overexpression of p53 was much more frequently observed among PanIN-3 than among carcinoma in situ in IPMN (P = 0.046 and 0.008, respectively). The Ki-67 labeling index was correlated with the histological grades of both PanINs and IPMNs (P = 0.0001 and P = 0.0001, respectively). There are different immunohistochemical expression patterns of p16INK4A and p53 between IPMNs and PanINs. These may substantiate their different genetic progressions to invasive carcinoma.
    Pancreas 02/2007; 34(1):85-91. · 2.95 Impact Factor
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    ABSTRACT: We aimed to elucidate the origin/primary site of invasive ductal adenocarcinoma of the pancreas, based on the distribution of intraductal carcinoma components. These components were identified by a mural elastic fiber cuff. Thirteen specimens from patients with invasive ductal adenocarcinoma (microscopically, less than 2 cm in diameter) of the pancreas were studied histopathologically. Variants of invasive ductal adenocarcinoma and intraductal papillary-mucinous carcinoma were excluded. Intraductal carcinoma components of invasive ductal adenocarcinoma were found in 12 of the specimens 13 (92%), and were observed within the tumor mass and/or on its boundary, or outside the tumor mass. Intraductal components were characterized by low papillary projections lacking a fibrovascular core, with/without surrounding tubular structures, or by irregular stratification and pleomorphism of the epithelial cells. Invasive components mostly showed a tubular pattern with desmoplasia. The distribution of the intraductal components in the 12 specimens was as follows: in 9 (75%), they were in both the main pancreatic duct and large branch ducts; and in 3, they were in the smaller branch ducts only. Invasive ductal adenocarcinomas of the pancreas may originate most frequently from the main pancreatic duct or larger branch ducts, while the smaller ducts are less often the site of cancer origin.
    Journal of Hepato-Biliary-Pancreatic Surgery 02/2007; 14(3):283-8. · 1.60 Impact Factor
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    ABSTRACT: Primary liposarcoma of bone is exceedingly rare. We report a case of primary pleomorphic liposarcoma in the humerus of a 38-year-old female. Radiographs demonstrated an expansile and osteolytic lesion extending from the head to the proximal part of the shaft in the right humerus. MR study showed a defined lesion in the humerus. The lesion had an iso-signal intensity and partial high-intensity lesion on T1-weighted images and a heterogeneous high signal intensity on T2-weighted images. Wide resection and proximal humeral endoprosthesis replacement were performed. Final pathological diagnosis of the lesion was pleomorphic liposarcoma. This is the second reported case of pleomorphic liposarcoma of the bone, and the first case presenting MRI findings for liposarcoma of bone.
    Skeletal Radiology 08/2006; 35(7):536-8. · 1.74 Impact Factor
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    ABSTRACT: Mucinous cystic neoplasms (MCN) of the pancreas are mucin-producing cystic tumors with an ovarian-like stroma (OLS). In the present study MCN were obtained from 27 patients. These MCN were derived from 22 pancreas, three livers, spleen, and mesentery. MCN in various organs have common clinicopathological profiles, being unilocular or multilocular cystic tumors, with a fibrous capsule and lined by mucin-secreting epithelium associated with an underlying subepithelial OLS. The OLS showed strong positivity for alpha-smooth muscle actin (alpha-SMA) and vimentin and weak, focal positivity for desmin. Both estrogen receptors and progesterone receptors were expressed in the nuclei of OLS cells. In addition, 20 ovarian MCN and 13 normal ovaries were studied with particular attention to the stroma. The stroma of ovarian MCN was strongly immunopositive for alpha-SMA and vimentin and focally positive for desmin, whereas normal ovarian stroma was immunonegative for both alpha-SMA and desmin. The OLS of MCN mentioned here was similar to the septa of ovarian MCN but not to ovarian stroma. In conclusion, MCN in various organs should be lumped together as 'extra ovarian' MCN. The OLS was identified on the basis of myofibroblastic proliferation both in response to neoplastic development and dependent on hormones.
    Pathology International 03/2006; 56(2):71-7. · 1.72 Impact Factor
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    ABSTRACT: We attempted to discriminate between carcinoma in situ (CIS) and the intraductal invasion/cancerization of invasive ductal carcinoma (IDC) of the pancreas, by comparing the histological patterns of the intraductal components and those of venous invasion. Specimens from 30 patients with IDC were examined histopathologically. Intraductal components and blood vessel invasion in IDC were assessed in specimens stained with hematoxylin & eosin and elastica van Gieson (EVG). Intraductal components of IDC were found in 28 of the 30 cases of IDC, in 261 ducts, and in 2.3 ducts per one section of one case, on average. The intraductal components of IDC were classified into three histological patterns, as follows: low papillary (including flat), tubular (including solid and cribriform), and mixed (low papillary plus tubular). The incidences of the low papillary, tubular, and mixed patterns in the 261 ducts, were 39% (102 ducts), 56% (145 ducts), and 5% (14 ducts), respectively. The histological pattern of venous invasion was tubular in all but 1 of the 26 cases, and this 1 case showed low papillary patterns as well as a tubular pattern. A tubular pattern of intraductal components in IDC of the pancreas indicates intraductal invasion, while a low papillary pattern indicates CIS or carcinoma in another location to which it has spread.
    Journal of Hepato-Biliary-Pancreatic Surgery 01/2006; 13(3):235-8. · 1.60 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Pancreas 06/2005; 31(1):6-7. · 2.95 Impact Factor
  • Histopathology 06/2005; 46(5):594-6. · 2.86 Impact Factor
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    ABSTRACT: Although primary Sjogren's syndrome (pSS) is an autoimmune exocrinopathy, the involvement of liver has been reported. Because no study focusing on autoimmune hepatitis (AIH) in pSS has been published, the purpose of the present study was to perform a clinical and histological examination of the liver, focusing on AIH, in 17 pSS patients. The patients had liver enzyme abnormalities without hepatitis virus infection. In all cases, biopsied livers were examined, and in 10 cases biopsied labial salivary glands were also examined histologically. Based on the authors' diagnostic criteria for AIH in pSS, the liver diseases consisted of AIH (eight cases, 47%), primary biliary cirrhosis (PBC; six cases, 35%), non-specified chronic hepatitis (two cases, 12%) and acute hepatitis (one case, 6%). Lymphoplasmacytic infiltrate, with predominancy of CD3(+) T cells, was noted in both the liver and salivary glands in the patients with AIH. The patients with AIH with severe interface hepatitis had a good response to immunosuppressive therapy. The comparison of liver histology between the PBC with pSS group and the PBC without pSS group showed that the incidence of lymphoid non-suppurative cholangitis was higher in PBC with pSS. In conclusion, the present study offers new information on the relatively common occurrence, diagnostic criteria and treatment effects of AIH in pSS.
    Pathology International 03/2005; 55(2):70-6. · 1.72 Impact Factor
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    ABSTRACT: To investigate the prevalence of human papillomavirus (HPV) infection in patients attending a gynecologic outpatient department, and to correlate the infection status with the presence or absence of uterine cervical lesions and the grades assessed by cytological or histological examinations. Five hundred and seventy-two subjects were studied. In all subjects, HPV detection by the hybrid capture method and a cervical cytological examination were performed The HPV-positive rate in subjects with normal cytology was 12.3%. The detection rate was high (21.7%) in subjects aged in the twenties and low in the forties, and HPV was not detected in subjects aged in the sixties and seventies. When HPV-positive rates were examined according to cytological or histological grades, the rates were higher in subjects with abnormal cytology (P < 0.01) or cervical intraepithelial neoplasia (CIN) or squamous cell carcinoma compared with those with normal cytology. Diagnosis of HPV infection is also important for the prediction of progression to CIN and cervical cancer.
    Journal of Obstetrics and Gynaecology Research 10/2004; 30(5):380-5. · 0.84 Impact Factor
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    ABSTRACT: Carcinosarcoma (spindle cell carcinoma) of the esophagus is a rare neoplasm that shows squamous cell carcinoma (SCC) with a variable component of spindle cell sarcoma. Clinical and pathologic features of this neoplasm have been well documented, but the histogenesis has long been a matter of speculation and dispute. In an attempt to clarify the clonality and genetic relationships in the evolution of this neoplasm, we microdissected a total of 36 carcinomatous and sarcomatous foci from six esophageal carcinosarcoma (CS) and analyzed the allelic status with 25 microsatellite markers on chromosomal arms 3p, 5q, 6q, 8p, 9p, 11q, 13q, 17p, and 18q. In all cases, we found multiple and homogenous allelic losses in both the carcinomatous and sarcomatous components, strongly supporting the concept of monoclonal origin for this neoplasm. Homogeneous allelic losses were detected most frequently on 17p (5 cases), a chromosomal arm that included the p53 locus, followed by 3p, 11q, and 13q (3 cases); 9p (2 cases); and 8p and 18q (1 case). Moreover, five of the six cases showed additional or divergent allelic losses at more than one chromosomal locus at some of the microdissected foci, indicating genetic progression (2 cases) or genetic progression and divergence (3 cases). In four cases, the genetic changes indicated that an original clone of a pure SCC apparently acquired carcinosarcomatous or sarcomatous phenotype by successive genetic changes. On the other hand, we saw no evidence for tumors in which a sarcoma appeared to give rise to a carcinosarcomatous or carcinomatous subclone in the examined cases. In conclusion, our data support the concept that esophageal CS is derived from a single clone originating from a SCC. Furthermore, we showed genetic heterogeneity to accompany the phenotypic divergence, with patterns of genetic alterations that are consistent with both progression and divergence within individual tumors.
    Human Pathlogy 04/2004; 35(3):322-7. · 2.84 Impact Factor
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    ABSTRACT: Two Japanese brothers were diagnosed in their 20s with familial pulmonary fibrosis, the pathological findings of which were consistent with usual interstitial pneumonia (UIP). However, an atypical characteristic was observed in the lungs of these brothers; 2-mm areas of 'honeycomb' were identified throughout the lungs, which is smaller than the generally observed 5-10 mm honeycombing seen in UIP. Fibroblastic foci were demonstrated in the second eldest brother, but not in the eldest, which indicates that the lungs of the eldest brother was in a more advanced stage of fibrosis. Their youngest brother and parents have no clinical evidence of pulmonary fibrosis. All five family members had low values for the diffusion capacity of the lung for carbon monoxide (DLCO), suggesting the presence of an inheritable disease and the existence of different phenotypes. The genomic DNA of the affected brothers was sequenced for the reported surfactant protein C (SP-C) gene mutations in patients with familial pulmonary fibrosis, but none was documented. It is necessary to clarify the presence of novel gene mutations of SP-C or other genes to explain these particular pathological findings and the low DLCO observed in this family.
    Pathology International 02/2004; 54(1):41-6. · 1.72 Impact Factor
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    ABSTRACT: The role of the ampullary mucosa, especially its distended glands at the papilla of Vater, has not been fully explored. Twenty-nine pancreatoduodenectomized specimens from pancreatobiliary diseases and 44 autopsied cases, as controls, were studied histopathologically and immunohistochemically. In 12 out of the 29 pancreatoduodenectomized cases the ampullary mucosa was in contact with the duodenal mucosa just at the outlet of the ampulla. In the remaining 17 cases, the ampullary mucosa overgrew beyond the ostium, replacing a portion of the surrounding duodenal mucosa, termed "distended glands," which measured an average of 1532 microm in length. The muscularis mucosae of the duodenum and the Oddi's sphincter muscle merged in an "end-to-end, sharp-angled" manner at the ostium in the former, whereas this occurred in an "end-to-side, less sharp, rather right-angled" manner in the latter. Immunohistochemically, the distended glands in some cases showed negative/weakly positive staining for anti-carbohydrate antigen (CA) 19-9 and a high proliferation index evaluated using Ki67. In the autopsied materials, distended glands were found in 24 out of the 44 cases. Distended glands of the ampullary mucosa were frequently found and only grew on the Oddi's sphincter muscle extension. They may represent not only malignant change but also an adaptive phenomenon for bile and pancreatic juice flow.
    Journal of Hepato-Biliary-Pancreatic Surgery 02/2004; 11(4):260-5. · 1.60 Impact Factor
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    ABSTRACT: Esophageal carcinoma is a challenging target for radiotherapy. To improve treatment efficacy, an investigation of a predictive factor is desirable. In this study, we evaluated the significance of apoptosis and immunohistochemical staining for p53, Ki-67, c-erbB-2 (HER-2/neu), Ku (p70/p80), and DNA-PKcs for predictive markers of the responsiveness to chemoradiotherapy in esophageal squamous cell carcinoma. This retrospective analysis consisted of 34 patients with esophageal squamous cell carcinoma in whom tumor biopsy was performed before treatment. They were divided into chemoradiosensitive (n = 13) and chemoradioresistant (n = 21) groups according to the tumor response evaluated at a total radiation dose of 40 Gy. The biopsy samples were examined with immunohistochemical staining for various factors and with an in situ nick end labeling method for apoptosis. The examined data were compared between the two groups. The difference in the Ki-67, p53, Ku (p70/p80), DNA-PKcs labeling indexes and the apoptosis index in tumor cells between the chemoradiosensitive and chemoradioresistant groups was not statistically significant. The expression of c-erbB-2 oncoprotein was statistically significant in the chemoradioresistant group (p = 0.02), although it did not correlate with survival. c-erbB-2 immunostaining is useful for the prediction of chemoradioresistance in esophageal squamous cell carcinoma.
    International Journal of Radiation OncologyBiologyPhysics 01/2004; 57(5):1323-7. · 4.52 Impact Factor
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    ABSTRACT: Many intraductal papillary-mucinous tumors (IPMTs) have been diagnosed with improvements in diagnostic imaging techniques. The histology of IPMT is various, including hyperplasia to invasive carcinoma. IPMTs are thought to occur multicentrically through the hyperplasia-adenoma-carcinoma sequence. IPMTs are characterized by genetic heterogeneity associated with histologic heterogeneity that may be due to slow growth and favorable prognosis. However, some IPMTs progress to invasive pancreatic cancer through malignant transformation with aggressive clonal progression. Thus some conventional pancreatic cancers may be derived from IPMTs. Although IPMTs and conventional pancreatic cancer initially occur in the ductal epithelium, they are thought to be totally different entities in terms of large or peripheral pancreatic duct origin, developmental style, genetic alterations, and prognosis. In future, differences and/or similarities will be discussed on the basis of molecular analyses of the carcinogensis of both tumors.
    Nippon Geka Gakkai zasshi 07/2003; 104(6):439-42.
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    ABSTRACT: Rectovaginal (RV) endometriosis presents with a nodular lesion composed of fibromuscular and endometriotic tissue, and the fibromuscular tissue is the major component in the severe stage. The purpose of our study was to examine the extending process of fibromuscular tissue in RV endometriosis. Histological examinations using immunostains, were performed in 90 RV tissue specimens from 37 women. Fibrosis was present in 89 specimens. In each specimen, the intensity of the fibrosis differed from area to area: in mildly fibrotic areas, the collagen fibers were present around the endometriotic tissue, and in severely fibrotic areas, the fibrosis widely extended into fat and connective tissus as well as within the endometriotic tissue. In the 60 specimens containing endometriotic tissue, the increase in the amount of endometriotic tissue significantly correlated to the increase in degree of fibrosis in the entire tissue. The presence of aggregated smooth muscles, unassociated with blood vessels, was defined as smooth muscle metaplasia (SMM), which was always present within the fibrotic areas, and was observed in 80 specimens. The degree of SMM in the entire tissue was significantly correlated with the degree of fibrosis. From these findings, the following was hypothesized. Initially, endometriotic tissue was present sporadically and fibrosis was present around the endometriotic tissue. Thereafter, proliferation of endometriotic tissue and an increase in fibrosis occur consecutively. The SMM was present within the fibrotic areas, and it became more severe, correlating with the increase in fibrosis. In conclusion, this is the first report describing the extending process of the fibromuscular tissue of RV endometriosis from a histological viewpoint, and we think that recognization of this process is useful for histological diagnosis and clinical management of RV endometriosis.
    Pathology International 07/2003; 53(6):371-5. · 1.72 Impact Factor
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    ABSTRACT: To clarify the mechanism of origin of duodenal wall cysts in patients with chronic pancreatitis, developing into duodenal stenosis. Specimens from 12 pancreatoduodenectomized patients with chronic pancreatitis and 51 controls were studied histopathologically and immunohistochemically. Variously shaped cystic lesions, averaging about 15 mm in diameter, were found in the duodenum in six of the 12 patients with chronic pancreatitis, but were not observed in the controls. Each case had an average of two cysts, which were located mainly in the muscularis propria of the duodenum with or without submucosal or extraduodenal-peripancreatic extensions. The inner part of the cyst wall consisted of a moderate rim of granulation tissue, with both myofibroblasts and smooth muscle proliferation in the tissue surrounding the cyst and the submucosal layer of the duodenum, occasionally accompanied by an epithelial lining. A ductal structure in the muscularis propria of the duodenum, possibly a ductal component of ectopic pancreatic tissue, was found in five of the six cases. Some of these structures showed cystic changes. Three of the six patients had accompanying duodenal stenosis. Duodenal wall cysts occur mainly in the muscularis propria of the duodenum associated with both myofibroblasts and smooth muscle proliferation, and may result in duodenal stenosis. These cysts may be derived from a ductal component of ectopic pancreatic tissue.
    Histopathology 11/2002; 41(4):351-6. · 2.86 Impact Factor
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    ABSTRACT: Invasive ductal adenocarcinoma of the pancreas (IDAP) also spreads through the pancreatic ductal tree. The aim of this study was to clarify the clinicopathologic features of IDAP with intraductal spread. We studied the intraductal spread of IDAP and its correlation with clinicopathologic parameters in a surgical series of 54 patients. The pancreatic ducts were analyzed by confirmation of mural elastic fibers with elastica van Gieson stain. Intraductal spread of carcinoma was identified in 37 patients (69%). Such spread was frequent in well-differentiated IDAP (93%), and the number of intraductal carcinoma foci was correlated with the grade of tumor differentiation (p < 0.001). The large branch ducts were the main route of intraductal spread (64.1%). The proliferation index, evaluated using Ki67, was lower in the intraductal carcinoma components than in the associated infiltrating carcinoma components (p < 0.001). The presence or absence of intraductal spread was not correlated with age, sex, tumor location, tumor size, or stage. IDAP with intraductal spread showed a tendency, although it was not significant (p = 0.092), to be associated with longer survival compared with IDAP without intraductal spread. IDAP, especially of the well-differentiated type, has a tendency to spread intraductally. The difference between the Ki67 labeling indexes in the intraductal and associated infiltrating carcinoma components suggests that these components show different biological behaviors.
    Pancreatology 01/2002; 2(4):407-12. · 2.04 Impact Factor