Bulky peritoneal carcinosarcoma with tiny high-grade serous carcinoma of the fallopian tube: a case report.

Peritoneal carcinosarcoma is a highly aggressive and uncommon neoplasm that has carcinomatous and sarcomatous components; the malignancy rarely localizes to the omentum. We report a case of a bulky peritoneal carcinosarcoma with tiny high-grade serous carcinoma of the fallopian tube. A 60-year-old female with a huge pelvic mass (12 cm in diameter) underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy for tumor debulking. Pathological findings showed minimally invasive high-grade serous carcinoma of the left fallopian tube and carcinosarcoma of the omentum. Similar p53 diffuse immunostaining in the omental carcinosarcoma and the tubal carcinoma provides evidence for a clonal relationship between the two neoplasias. This case suggests a small serous carcinoma, originating in the tubal mucosa, subsequently became implanted in the omentum and grew preferentially, converting to a carcinosarcoma at a remote site.

A case of primary hepatic mixed neuroendocrine-non-neuroendocrine tumor (MiNEN) associated with gallbladder carcinosarcoma.

A woman in her seventies visited our hospital because of abdominal pain. Multiple hepatic tumors were detected and a liver biopsy revealed mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN), which was composed of cholangiocellular carcinoma and neuroendocrine tumor (NET). Diagnostic imaging ruled out primary malignancies other than the liver and identified that the tumor originated from the liver. Because a predominant and aggressive part of the tumor was considered to be cholangiocellular carcinoma, gemcitabine and S-1 were used as first-line treatment. After the treatment, octreotide acetate was administered for the NET component, followed by transcatheter arterial embolization. Subsequently, her gallbladder (GB) rapidly swelled with biliary tract obstruction, and cholecystectomy revealed carcinosarcoma of the GB. She is still undergoing treatment at 44 months after diagnosis. Herein we report this case of primary hepatic MiNEN consisting of cholangiocarcinoma and NET, followed by GB carcinosarcoma. This is the first case illustrating that a multidisciplinary treatment approach for MiNEN accompanied with carcinosarcoma, involving assessment and treatment targeting the most aggressive component, can result in a long survival time.

Radiological and Pathological Assessment of the 2017 Revised International Association of Pancreatology Consensus Guidelines for Intraductal Papillary Mucinous Neoplasm, With an Emphasis on the Gastric Pyloric Gland Type.

OBJECTIVES: This study aimed to assess the pitfalls of the current International Association of Pancreatology guidelines (IAPCG2017) for pancreatic intraductal papillary mucinous neoplasm (IPMN) and identify the criteria for future guidelines. METHODS: Eighty surgically resected, consecutive IPMN cases were analyzed. Data including tumor site, IPMN duct type, and surgery type were collected. Based on radiological data, cases were retrospectively classified as high-risk stigmata (HRS) and non-HRS. Pathological grades and histological subtypes of IPMN cases were determined. Severe stromal sclerosis of the IPMN septa/marked parenchymal atrophy in the upstream pancreas was investigated pathologically. Positive/negative predictive values of the IAPCG2017 were calculated. Clinicopathological features of HRS-benign cases (pathologically benign IPMN cases meeting the HRS criteria) were extracted. RESULTS: The positive/negative predictive values were 72.7%/64.0%, 70.0%/34.6%, and 54.0%/63.3% for IAPCG2017, HRS-main pancreatic duct, and HRS-nodule criteria, respectively. The 15 HRS-benign cases (18.8%) included 13 pancreatoduodenectomies and 10 cases of gastric pyloric (GP) gland subtype. Severe upstream atrophy was significantly related to IPMN malignancy, unlike the severe sclerosis of IPMN septa. CONCLUSIONS: Benign IPMNs of GP subtype are sometimes categorized as HRS with the IAPCG2017. Collecting data on the natural course of GP-IPMN is necessary. To evaluate upstream atrophy may be of value to predict IPMN malignancy.

[A Case of Primary Breast Cancer and Gastric Cancer Metastasis to the Skin-Usefulness of Immunohistochemistry in Differentiating Primary Breast Cancer from Metastatic Breast Cancer].

We herein report the case of a 76-year-old female patient who had undergone gastrectomy for advanced gastric cancer (histologically tubular adenocarcinoma)before 5 months, presenting with abdominal skin tumor. A skin biopsy revealed tubular adenocarcinoma. Positron emission tomography-computed tomographic scanning detected right breast tumor. A partial mastectomy of the right breast and local resection of abdominal skin tumor were performed and both tumors depicted similar histology of tubular adenocarcinoma in routine pathological examination. Immunohistochemically, positive for CDX2 and MUC5AC in previously resected gastric cancer and skin tumor tissues, whereas negative for both antigens in breast cancer. Thus, the final pathological diagnosis demonstrated skin metastasis originating from gastric cancer and primary breast cancer(invasive ductal carcinoma)histologically mimicking gastric cancer. We emphasize difficulties in diagnosis of this situation and that immunohistochemistry is helpful to distinguish primary breast cancer from gastric cancer metastasizing to the breast.

KCTD12 is negatively regulated by Kit in gastrointestinal stromal tumors.

Our group has previously demonstrated that pfetin, encoded by the KCTD12 gene, is a strong prognostic biomarker for gastrointestinal stromal tumors (GISTs). However, the underlying mechanisms that control pfetin expression remain unknown. To elucidate the regulatory mechanisms of KCTD12 in GIST, in addition to a possible association between KCTD12 alterations and protein expression, we examined 76 patients with GISTs for KCTD12 mutations by PCR-direct sequence, and compared these results with clinicopathologic data. The function of pfetin in GIST progression was also revealed using GIST T1 cells. In this series, pfetin expression was not observed in 15 cases, and loss of pfetin expression was associated with higher mitotic rate (>5/50HPFs: p = 0.029). There was also a trend between presence of necrosis and loss of pfetin expression but this was not statistically significant (p = 0.09). KCTD12 mutations were frequently observed in 22 out of 76 GISTs (28.9%); however, they did not affect protein expression and were not associated with patients' prognosis. KCTD12 in vitro knockdown resulted in the accelerated growth of GIST T1 cells, confirming that pfetin functions as a tumor suppressor. KIT knockdown significantly inhibited cellular growth and upregulated the expression of pfetin at both the mRNA and protein level. These findings suggest that GISTs with loss of pfetin expression has proliferative advantage and that higher pfetin expression in GISTs may be indicative of lower expression levels of KIT. This relationship confirms that pfetin is a useful prognostic marker in GISTs.

Immunohistochemical and genetic characteristics of a colorectal mucin-rich variant of traditional serrated adenoma.

AIMS: Recently, several morphological variants of traditional serrated adenoma (TSA) of the colorectum have been recognised, and mucin-rich TSA (MR-TSA) and serrated tubulovillous adenoma (S-TVA) were introduced as distinct morphological variants separate from conventional TSA (C-TSA). This aim of this study was to elucidate the immunohistochemical and genetic characteristics of MR-TSAs. METHODS AND RESULTS: We performed immunostaining for cytokeratins (CKs) (e.g. CK7 and CK20), mucins (e.g. MUC2, MUC5AC, MUC6, and CD10), ß-catenin, and MLH1, and direct sequencing of BRAF/KRAS, in 32 MR-TSAs, 35 C-TSAs, and 23 S-TVAs. Immunohistochemically, all studied cases were positive for CK20, whereas few cases were positive for CK7, with no significant differences between the three groups. Regarding mucin-phenotypic expression, all cases were positive for MUC2 but negative for MUC6 and CD10. MUC5AC positivity was found significantly more frequently in MR-TSAs (53%) than in C-TSAs (26%; P = 0.026). Nuclear ß-catenin expression in MR-TSAs was significantly less frequent than in S-TVAs (P = 0.002). MLH1 nuclear staining was retained in all cases. Genetically, MR-TSAs (75%) more frequently harboured BRAF mutation than C-TSAs (49%; P = 0.044) or S-TVAs (4%; P < 0.001), whereas only two cases (6%) of MR-TSA harboured a KRAS mutation, a frequency that was significantly lower than that in C-TSAs (26%; P = 0.047) or S-TVAs (57%; P < 0.001). CONCLUSIONS: MR-TSAs more frequently harboured BRAF mutations than C-TSAs, and had distinct immunohistochemical characteristics. Our findings indicated that MR-TSAs could be important precursors of BRAF-mutated, microsatellite-stable subtypes of colorectal carcinoma.

Distinct histopathological characteristics in colorectal submucosal invasive carcinoma arising in sessile serrated adenoma/polyp and conventional tubular adenoma.

The histopathological characteristics of colorectal submucosal invasive carcinoma arising in sessile serrated adenoma/polyp (SSA/P), a rare malignant tumour, have not yet been fully elucidated. To investigate the features of such, we retrospectively analysed 40 submucosal invasive carcinomas with SSA/P (CA-SSA/P) and compared them to 129 cases of submucosal invasive carcinoma with conventional tubular adenoma (CA-AD). We additionally performed hMLH1 immunostaining. CA-SSA/Ps were significantly smaller than CA-ADs (P < 0.001). Histologically, well to moderately differentiated adenocarcinoma was predominant in both CA-SSA/Ps and CA-ADs. No significant differences in depth of invasion were found between the two groups. However, lymphatic invasion was more often found in CA-SSA/Ps (30%) than in CA-ADs (13%; P = 0.028), as was lymph node metastasis (CA-SSA/Ps, 28%; CA-ADs, 7%; P = 0.011). Furthermore, mucinous component and serrated architecture were significantly more frequent in CA-SSA/Ps (30 and 63%) than in CA-ADs (5 and 18%; P < 0.001, respectively). Tumour-infiltrating lymphocytes and Crohn-like inflammatory reaction were also more frequently found in CA-SSA/Ps (70 and 30%) than in CA-ADs (31 and 9%; P ≤ 0.001, respectively), whereas the opposite was true of desmoplastic reaction (CA-SSA/Ps, 35%; CA-ADs, 67%; P < 0.001). Loss of hMLH1 expression was more frequent in CA-SSA/P cases (93%) than in CA-AD cases (5%; P < 0.001). In conclusion, CA-SSA/P lesions exhibit a higher potential for lymphatic invasion and lymph node metastasis and have distinct histopathological features, including mucinous component, serrated architecture, tumour-infiltrating lymphocytes, Crohn-like inflammatory reaction, and absence of desmoplastic reaction, compared to their conventional counterparts.

Primary Hepatic Lymphoma Complicated by a Hepatic Inflammatory Pseudotumor and Tumor-Forming Pancreatitis.

BACKGROUND: Hepatic inflammatory pseudotumor (IPT) is considered to be benign in biological behavior, and its malignant transformation is extremely rare. There has only been one published case of primary hepatic lymphoma complicated by hepatic IPT. CASE PRESENTATION: A 73-year-old man presented with obstructive jaundice and a pancreatic head mass. Histology of the mass revealed chronic pancreatitis with lymphoid follicle formation, leading to a diagnosis of a suspicion of follicular pancreatitis. After a choledochojejunostomy, a hepatic tumor was detected, and a biopsy revealed lymphoplasmacytic infiltration. Immunohistochemistry confirmed the polyclonal nature of lymphoplasma cells, indicative of an IPT. The hepatic tumor disappeared during follow-up, but the patient exhibited a high fever related to tumor recurrence. A biopsy revealed the co-existence of a diffuse large B-cell lymphoma and an IPT. IgG4-related disease was excluded because storiform fibrosis, obliterative phlebitis, and a significant increase in IgG4-immunoreactive cells were absent in all investigated tissues. The tumor completely disappeared after chemotherapy. CONCLUSION: Careful observation is necessary in this kind of situation because the presence of a hepatic IPT may represent an increased risk of malignant transformation.

Distinct Involvement of the Sonic Hedgehog Signaling Pathway in Gastric Adenocarcinoma of Fundic Gland Type and Conventional Gastric Adenocarcinoma.

BACKGROUND/AIMS: Gastric adenocarcinoma of fundic gland type (GAFG), which is a rare variant of gastric cancer, is reportedly associated with both Wnt/ß-catenin signaling activation and guanine nucleotide binding protein, alpha stimulating complex (GNAS) mutations. This study aimed to elucidate potential roles of the Sonic hedgehog (Shh) signaling pathway in GAFG. METHODS: We performed immunostaining for ß-catenin and Shh signal-associated proteins, including Patched (Ptch), Smoothened (Smo), and Glioma-associated oncogene-1 (Gli1), and the direct sequencing of GNAS/BRAF/KRAS in 27 GAFGs, and compared them with 30 conventional gastric adenocarcinomas (CGAs). RESULTS: GAFGs exhibited significantly lower immunoreactivity scores for Ptch, Smo, and Gli1 than CGAs. Moreover, while the Ptch score was significantly lower in the GAFG tumor areas than in the non-neoplastic areas adjacent to GAFG, the score was significantly higher in the CGA tumor areas than in the non-neoplastic areas. Similar trends were observed in the scores for Smo and Gli1. ß-Catenin expression and GNAS mutations were found in 22 (81%) and 8 (30%) of the 27 GAFGs respectively. Gli1 expression was significantly associated with mutations in GNAS. CONCLUSION: GAFG and CGA exhibited distinct Ptch, Smo, and Gli1 expression patterns. Downregulation of the Shh signaling pathway, as well as activation of the Wnt/ß-catenin signaling pathway, may therefore be associated with tumorigenesis in GAFG.

Epigenetic regulation of Wnt/ß-catenin signal-associated genes in gastric neoplasia of the fundic gland (chief cell-predominant) type.

Gastric neoplasia of the fundic gland (chief cell-predominant) type (GNCCP) is a rare variant of gastric tumor. This tumor is associated with activation of the Wnt/ß-catenin signaling pathway; however, the mechanisms underlying this activation remain unknown. To elucidate potential roles of Wnt/ß-catenin signal-associated gene methylation in GNCCP, we performed ß-catenin immunostaining and methylation-specific polymerase chain reaction (PCR) for their associated genes, including SFRPs, APC, AXIN2, and MCC, in 26 GNCCPs [i.e., 11 intramucosal (GNCCP-Ms) and 15 submucosal tumors (GNCCP-SMs)], and compared with 27 fundic gland polyps (FGPs), 12 FGPs with dysplasia (FGP-Ds), 27 conventional gastric adenocarcinomas (CGAs). Nuclear ß-catenin labeling indices were higher in GNCCPs and CGAs than in FGPs and FGP-Ds. SFRPs, APC, and AXIN2 were more frequently methylated in GNCCPs and CGAs (SFRP1, 88%/96%; SFRP2, 85%/93%; SFRP4, 73%/81%; APC, 81%/81%; AXIN2, 81%/85%; respectively) than in FGPs and FGP-Ds (37%/50%; 41%/42%; 41%/58%; 37%/33%; 41%/50%; respectively). A significant correlation was seen between nuclear ß-catenin expression and methylation of SFRP1 in GNCCPs. Furthermore, nuclear ß-catenin expression was significantly frequent in high-methylated GNCCPs than in low-methylated tumors. In conclusion, our results suggest that activation of this pathway, mediated by gene methylation, may be associated with progression of some GNCCP cases, similar to CGAs.

Distinct endoscopic characteristics of sessile serrated adenoma/polyp with and without dysplasia/carcinoma.

BACKGROUND AND AIMS: Sessile serrated adenoma/polyp (SSA/P) is a colorectal polyp that has malignant potential. However, the dysplastic components within an SSA/P can be difficult to detect. This study aimed to clarify the endoscopic characteristics of SSA/P with advanced histology. METHODS: We examined 462 endoscopically or surgically resected lesions that were pathologically diagnosed as SSA/P, including 414 without and 41 with cytologic dysplasia, and 7 with invasive carcinoma. We retrospectively studied the clinicopathologic and endoscopic characteristics and performed pit pattern analysis. RESULTS: A stepwise increase in the size of the SSA/P series was identified along with their dysplastic progression, although 19 of 48 (39.6%) SSA/Ps with dysplasia/carcinoma were ≤10 mm in size. Most lesions were covered with a mucus cap. Macroscopically, (semi)pedunculated morphology, double elevation, central depression, and reddishness were found more frequently in SSA/P with cytologic dysplasia and invasive carcinoma ([semi]pedunculated morphology, 17.1%/28.6%; double elevation, 63.4%/57.1%; central depression, 9.8%/28.6%; reddishness, 39.0%/85.7%) than in those without dysplasia (4.6%, 4.6%, 3.9%, and 3.4%, respectively). Furthermore, the presence of at least 1 of these 4 markers had high sensitivity (91.7%) for identifying the dysplasia/carcinoma within a SSA/P, with a specificity of 85.3%. In the pit pattern analysis, all SSA/Ps without dysplasia exhibited type II pit pattern only, whereas 94.4% of SSA/Ps with dysplasia/carcinoma showed type II in addition to type IIIL, IV, VI, or VN pit patterns. CONCLUSIONS: In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, in addition to the use of magnifying endoscopy, may be useful to accurately diagnose advanced histology within an SSA/P.

Ulcerative Colitis-associated Cancer/Dysplasia Detected Using Surveillance Colonoscopy Performed in the Clinical Remission Phase: A Report of Five Cases.

We herein report five cases of ulcerative colitis-associated cancer/dysplasia. Although clinical remission had been achieved in all patients, mucosal inflammation had been resolved in only one patient. Thus, in order to prevent cancer from developing, appropriate medical therapy aiming not only to relieve the clinical symptoms, but also to suppress chronic inflammation appears to be necessary. Moreover, cancer occurred as early as 4 years after the diagnosis in one patient. In patients without complete resolution of mucosal inflammation, careful surveillance colonoscopy should be initiated in the early phase.

Fundic gland differentiation of oncocytic/pancreatobiliary subtypes of pancreatic intraductal papillary mucinous neoplasm.

AIMS: Intraductal papillary mucinous neoplasms (IPMNs) differentiate in several histological directions, which are related to their clinical behaviour. Differentiation of IPMNs to the gastric foveolar epithelium/pyloric gland (PG) is well known. However, no study has been conducted regarding fundic gland (FG) differentiation. The aim of this study was to determine the frequency of FG differentiation and its relationship with the clinicopathological features of IPMNs, by studying 48 surgically resected IPMN cases consisting of 17 gastric IPMNs, 15 intestinal IPMNs, 10 pancreatobiliary IPMNs, and six oncocytic IPMNs. METHODS AND RESULTS: Clinicopathological data, including histological tumour grade, immunohistochemical data for mucins (MUCs), pepsinogen I, pepsinogen II, and H,K-ATPase, and GNAS/KRAS status, were analysed. Pepsinogen I and H,K-ATPase were used to assess FG differentiation, and pepsinogen II and MUC6 were used to identify the equivalent cell type of the normal FG. Reverse transcription polymerase chain reaction (RT-PCR) for PGA5/PGC (pepsinogen I and pepsinogen II mRNA, respectively) and quantitative real-time RT-PCR (qRT-PCR) for PGA5 were performed to confirm the immunohistochemistry results. Pepsinogen I expression was detected in 12.5% (6/48) of total IPMNs, of which 66.7% (4/6) of oncocytic IPMNs and 20.0% (2/10) of pancreatobiliary IPMNs were pepsinogen I-positive. No H,K-ATPase-positive cases were detected. Three oncocytic IPMNs with pepsinogen I expression showed similar histology to normal FG. RT-PCR and qRT-PCR confirmed the immunohistochemical results. All IPMNs with FG differentiation were of the oncocytic or pancreatobiliary subtype, were of histologically high grade, and were without GNAS mutation. CONCLUSIONS: The differentiation of IPMNs to gastric FG is related to oncocytic and pancreatobiliary subtypes, and to high grade. This is the first report to describe differentiation of IPMNs to the FG, and to reveal its relationship with the clinicopathological features of IPMNs.

Expression of DNA double-strand break repair proteins predicts the response and prognosis of colorectal cancer patients undergoing oxaliplatin-based chemotherapy.

DNA intrastrand cross-linking agents such as oxaliplatin induce DNA double-strand breaks (DSBs) during DNA repair and replication. In the present study, we hypothesized that DNA intrastrand cross-linking agents may significantly benefit colorectal cancer patients with deficiencies in DSB repair. Seventy-eight patients with metastatic or recurrent colorectal cancer who had measurable target lesions and who underwent resection for primary colorectal cancer in our institution between April 2007 and March 2013 were included in the present study. The median age was 64.5 years, and the cohort consisted of 49 males and 29 females. The median progression-free survival (PFS) was 10.9 months. The expression of DSB repair proteins such as RAD51 and MRE11 was investigated by immunohistochemistry, and associations between RAD51 and MRE11 expression and clinicopathological factors or chemotherapeutic effect were assessed. MRE11-negative cases and RAD51-negative cases achieved significantly better tumor reduction compared with cases with positive expression. Cases with negative expression of both proteins or negative expression of either protein had significantly longer PFS than cases with positive expression for both proteins. In conclusion, DSB repair protein expression-negative colorectal cancer cases may be more highly sensitive to chemotherapy, and thus DSB repair protein expression may be a useful prognostic indicator for colorectal cancer patients.

Clinicopathologic and immunohistochemical characteristics of gastric adenocarcinoma with enteroblastic differentiation: a study of 29 cases.

BACKGROUND: Gastric adenocarcinoma with enteroblastic differentiation (GAED) has been recognized as a variant of alpha-fetoprotein (AFP)-producing gastric carcinoma, although its clinicopathologic and immunohistochemical features have not been fully elucidated. METHODS: To elucidate the clinicopathologic and immunohistochemical features of GAED, we analyzed 29 cases of GAED, including ten early and 19 advanced lesions, and compared these cases with 100 cases of conventional gastric adenocarcinoma (CGA). Immunohistochemistry for AFP, glypican 3, SALL4, and p53 was performed, and the phenotypic expression of the tumors was evaluated by immunostaining with antibodies against MUC5AC, MUC6, MUC2, CD10, and caudal-type homeobox 2 (CDX2). RESULTS: Lymphatic and venous invasion was more frequent in GAED (76 and 72 %) than in CGA (41 and 31 %; P ≤ 0.001). Lymph node metastasis was more frequently observed in GAED (69 %) than in CGA (38 %; P = 0.005), as were synchronous or metachronous liver metastases (GAED, 31 %; CGA, 6 %; P ≤ 0.001). Immunohistochemically, all GAED were positive for at least one of three enteroblastic linage markers (AFP, glypican 3, and SALL4). Glypican 3 was the most sensitive marker (83 %) for GAED, followed by SALL4 (72 %) and AFP (45 %), whereas no CGA was positive. Furthermore, the rate of positive p53 staining was 59 % in GAED. Regarding the mucin phenotype, CD10 and CDX2 were diffusely or focally expressed in all GAED cases. Invasive areas with hepatoid or enteroblastic differentiation were negative for CD10 and CDX2. CONCLUSIONS: Clinicopathologic features of GAED differ from those of CGA. GAED shows aggressive biological behavior, and is characteristically immunoreactive to AFP, glypican 3, or SALL4.

Molecular pathology and potential therapeutic targets in esophageal basaloid squamous cell carcinoma.

Basaloid squamous cell carcinoma (BSCC) is a rare and poorly differentiated variant of typical squamous cell carcinoma. Emerging studies show that genetic alterations are more frequent in BSCC than in conventional SCC, and some of which led to the identification of potential therapeutic targets in esophageal BSCC. Approximately half of the esophageal BSCC cases harbor either an EGFR mutation or amplification, and these occur in a mutually exclusive fashion. Therefore, the application of tyrosine kinase inhibitors may be beneficial to esophageal BSCC patients. This tumor is partly characterized by the activation of the Wnt and Hedgehog (HH) signaling pathways. Wnt signaling is activated by SFRP2 promoter hypermethylation and HH signaling is activated by the frequent mutations in PTCH1. Increasing evidence shows that the Wnt signaling pathway is involved in cross-talk with other developmental pathways, including the HH pathway. Therefore, pharmaceutical therapy targeting both the HH and Wnt pathways would be quite effective in patients with esophageal BSCC with highly malignant potential. In this review, we discuss the pathology, prognostic factors, genetic alterations and potential therapeutic targets in BSCC of esophagus.

Alteration of Delta-like ligand 1 and Notch 1 receptor in various placental disorders with special reference to early onset preeclampsia.

Notch signaling pathway has been shown to be dysregulated in placentas with preeclampsia, but there has been a lack of studies on methylation of Notch family genes in this disorder. We therefore executed methylation-specific polymerase chain reaction and immunostaining for Notch 1 receptor and the activating ligand, Delta-like (DLL) 1, with placental tissues from cases of preeclampsia (early onset, n = 18; late-onset, n = 19) and other placental disorders, including maternal complications such as diabetes mellitus and collagen disease (n = 10), fetal growth restriction (n = 17), fetal anomaly (n = 23), preterm birth (n = 15), miscarriage (n = 25), and hydatidiform moles (n = 9) as well as term births (n = 12). The frequency of DLL1 methylation was higher in early onset preeclamptic placentas (61%) than the other subjects (0%-36%; P ≤ .016). Appreciable samples (36%) of miscarriage also represented DLL1 methylation. None of the samples studied showed Notch 1 methylation. On gestational period-matched analysis, the rate of DLL1 methylation was higher in early onset preeclampsia (83.3%) than preterm birth (13.3%; P < .001), with no significant differences in clinical backgrounds between the two. In this analysis, increase of syncytial knots and accelerated villous maturation were most prominent in DLL1-methylated placentas with early onset preeclampsia. Notch 1 and DLL1 expressions in villous trophoblasts and endothelial cells were significantly lower in early onset preeclamptic placentas as compared with preterm birth controls. In conclusion, altered Notch signaling via methylation of DLL1 is likely involved in possible disease-related mechanisms of early onset preeclampsia. Alternatively, DLL1 methylation in early onset preeclampsia could be a manifestation of a lack of placental maturation, similar to miscarriage.

Mutation spectrum in the Wnt/ß-catenin signaling pathway in gastric fundic gland-associated neoplasms/polyps.

Frequent activation of the Wnt/ß-catenin signaling pathway has recently been demonstrated in gastric adenocarcinoma/neoplasia of chief cell predominant type (GA-CCP/GN-CCP) with submucosal involvement. In this study, we examined the activation status of the Wnt/ß-catenin signaling pathway in GN-CCP without submucosal involvement, which is referred to as gastric dysplasia-CCP (GD-CCP). We also examined ß-catenin expression and the mutation spectrum of PPP2R1A and Wnt pathway genes in 11 cases of GD-CCP, 25 cases of gastric polyps of fundic gland type (GPs-FG), and 21 cases of GPs-FG with dysplasia (GP-FGD). ß-catenin nuclear staining was observed in 3 cases of GD-CCP, none of GPs-FG, and 6 cases of GPs-FGD. Mutations in Wnt pathway genes, including PPP2R1A, were observed in 4 cases of GDs-CCP, 10 cases of GPs-FG, and 7 cases of GPs-FGD. Two of these seven GPs-FGD cases showed ß-catenin nuclear staining. However, none of the 4 GD-CCP cases with mutations or the 10 GPs-FG cases with mutations showed ß-catenin nuclear staining. PPP2R1A mutations were observed in 1 GD-CCP case and 1 GPs-FGD case. Although the mutation spectra of the Wnt pathway genes in GD-CCP and GP-FG differed, based on the absence of ß-catenin nuclear staining despite the genetic alterations, GD-CCP is more similar to GP-FG than to GN-CCP, which shows ß-catenin nuclear staining and submucosal involvement. Activation of the Wnt/ß-catenin signaling by the ß-catenin nuclear transition may be required during progression from GD-CCP to GN-CCP. Furthermore, this is the first report describing PPP2R1A mutations in gastric fundic gland-associated neoplasms.

PTCH1 mutation is a frequent event in oesophageal basaloid squamous cell carcinoma.

Basaloid squamous cell carcinoma (BSCC) is a rare and poorly differentiated variant of typical squamous cell carcinoma, and is characterised in part by activation of the Wnt signalling pathway. We previously demonstrated that constitutive activation of the Wnt signalling pathway by epigenetic silencing of secreted frizzled-related protein 4 (SFRP4) is observed in this tumour. Increasing evidence shows that the Wnt signalling pathway cross-talks with other developmental pathways, including the Hedgehog (HH) pathway. The HH pathway is stimulated by inactivating mutations of PTCH1, which have a well-described oncogenic role in basal cell carcinoma (BCC) of the skin. We employed polymerase chain reaction followed by direct sequencing to detect inactivating mutations of PTCH1 using archival tissue samples of 30 oesophageal BSCCs. The frequency of PTCH1 mutation was compared to that of Wnt component genes that we reported previously. We found PTCH1 mutations in 53.3% (16/30) of cases, revealing T1195S as a hotspot mutation. This frequency is quite high for cancers other than BCC of the skin, and PTCH1 mutations were almost mutually exclusive with mutations in APC, Axin1 and Axin2. Considering the fact that activation of Wnt signalling via down-regulation of APC and SFRP5 due to promoter methylation is observed in BCC of the skin, Wnt signalling activation in oesophageal BSCC might be a secondary effect of the PTCH1-inactivating mutations. These findings suggest that the HH and Wnt pathways coordinately contribute to tumourigenesis in oesophageal BSCC. Furthermore, this study provides a potential therapeutic application for HH pathway inhibitors in oesophageal BSCC with highly malignant potential.

Effect of skip lymphovascular invasion on hepatic metastasis in colorectal carcinomas.

BACKGROUND: "Skip" lymphovascular invasion presenting as discontinuous foci of tumor cells within the colon wall is now excluded from consideration when determining T stage in the TNM classification. The purpose of this study was to assess the clinicopathological characteristics of colorectal cancer (CRC) patients with such skip lymphovascular invasion. METHODS: First, a retrospective questionnaire survey of the incidence of skip lymphovascular invasion was performed for a total of 1,868 patients with CRCs at ten institutions. Next, we comparatively assessed clinicopathological data for 896 CRC patients with or without skip lymphovascular invasion. RESULTS: The incidence of skip lymphovascular invasion was 1.1 % (20 out of 1,868). Most of the affected cases were rectal, pT2, and node negative, with moderately differentiated histology. Skip lymphovascular invasion was present in the muscularis propria and subserosa, with the tumors directly invading submucosa (pT1) or muscularis propria (pT2). Hepatic metastasis was greater in CRC with skip lymphovascular invasion (25 %) than in pT1/2 CRC (0 %; P < 0.001) or pT3 CRC without such invasion (13.8 %; P = 0.185). CONCLUSIONS: Our study suggests that skip lymphovascular invasion is associated with hepatic metastasis in CRC cases. Thus, definition of a T category including such invasion would be useful for clinical practice.