Tumor-to-tumor metastasis of colon cancer metastasizing to a pancreatic neuroendocrine tumor associated with von Hippel-Lindau disease: a case report.

Von Hippel-Lindau disease (VHL) is frequently associated with pancreatic neuroendocrine tumors (PNETs). Here, we report a case of tumor-to-tumor metastasis in a VHL patient in whom colon cancer metastasized to the interior of a PNET. A 65-year-old man had undergone bilateral adrenalectomy for pheochromocytomas in both adrenal glands in his 50 s. Genetic screening was performed considering his family history of pheochromocytoma, and he was diagnosed with VHL. PNET was detected, for which the patient was regularly monitored by follow-up imaging. One year ago, the patient underwent right hemicolectomy to remove a tumor in the ascending colon (pT3N0M0, pStage IIA). He was admitted to our department for detailed examination because the pancreatic tumor had grown, and thus, pancreaticoduodenectomy was performed. Diagnostic imaging and histological findings indicated tumor-to-tumor metastasis, in which the patient's previous colon cancer had metastasized to and proliferated within the PNET. Colon cancer metastasizing to a PNET is extraordinarily rare and has never been reported in the literature. Thus, practitioners should be vigilant for tumor-to-tumor metastasis when performing imaging surveillance of PNETs.

Risk of delayed bleeding after hot snare polypectomy and endoscopic mucosal resection in the colorectum with continuation of anticoagulants.

BACKGROUND: Current guidelines recommend the temporary discontinuation of anticoagulants before colonoscopic polypectomy, but the effect of this practice on reducing the risk of delayed bleeding after hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR) remains unclear. Our aim was to assess the impact of anticoagulants on the risk of colorectal delayed bleeding after HSP and EMR, and evaluate the necessity of drug withdrawal. METHODS: We reviewed the clinical data of patients with colorectal polyps using antithrombotic drugs who underwent HSP and/or EMR between January 2016 and September 2020 at Nagaoka Red Cross Hospital. After excluding antiplatelet users, patients were classified into those who continued anticoagulants [continuation group: 50 patients (93 lesions)] and those who discontinued anticoagulants [discontinuation group: 87 patients (190 lesions)]. RESULTS: Delayed bleeding occurred in 12 lesions, and there was no significant difference in the incidence rates between the continuation and the discontinuation groups (3.2% vs. 4.7%; P=0.756). Logistic regression analysis showed that continued use of anticoagulants was not a significant risk factor for delayed bleeding compared to anticoagulant discontinuation (odds ratio, 0.670; 95% CI, 0.177-2.537; P=0.556). There was no significant difference in the incidence rate and risk of delayed bleeding, regardless of the length of the anticoagulant withdrawal period. CONCLUSIONS: Continued use of anticoagulants, compared to their discontinuation, did not increase the risk of colorectal delayed bleeding after HSP and EMR. Our results suggest that current guideline recommendations for anticoagulant withdrawal before colonoscopic polypectomy may be reconsidered. TRIAL REGISTRATION: UMIN000040449.

Correction to: The search, coagulation, and clipping (SCC) method prevents delayed bleeding after gastric endoscopic submucosal dissection.

The article "The search, coagulation, and clipping (SCC) method prevents delayed bleeding after gastric endoscopic submucosal dissection", written by Motoi Azumi, Manabu Takeuchi, Youhei Koseki, Masaru Kumagai, Yoko Kobayashi, Masafumi Takatsuna, Aiko Yoshioka, Seiichi Yoshikawa, Tsutomu Miura, and Shuji Terai, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 28 September 2018 without open access.

The search, coagulation, and clipping (SCC) method prevents delayed bleeding after gastric endoscopic submucosal dissection.

BACKGROUND: Delayed bleeding is an important complication after gastric endoscopic submucosal dissection (ESD). The search, coagulation, and clipping (SCC) method can be used to prevent delayed bleeding after ESD. However, its safety and efficacy are unclear. We compared the SCC method with post-ESD coagulation (PEC) to clarify the safety and efficacy of the SCC method for preventing delayed bleeding after gastric ESD. METHODS: This retrospective study included 438 patients (478 lesions) who underwent gastric ESD. Multivariate logistic regression analysis was performed to identify the significant independent factors associated with delayed bleeding and we performed propensity-score matching (PSM) to reduce the effect of procedure-selection bias of SCC method. RESULTS: Of the 438 patients, 216 underwent PEC and 222 underwent SCC. Delayed bleeding was significantly less common in the SCC than in the PEC (2.6% vs. 7.2%; P = 0.013). Among patients treated with antithrombotic therapy, the delayed bleeding rate was lower in the SCC group than in the PEC group; however, the difference was not significant (P = 0.15). The SCC method was found to be a significant independent factor for the prevention of delayed bleeding. PSM was performed in 156 patients in the PEC group and SCC group. There was a significant difference in the incidence of bleeding in the PEC and SCC groups (P = 0.013). No patient had perforation/bleeding associated with the SCC method. CONCLUSIONS: Our findings suggest that the SCC method is a simple, safe, and effective approach for preventing delayed bleeding after gastric ESD.

High-grade PanIN presenting with localised stricture of the main pancreatic duct: A clinicopathological and molecular study of 10 cases suggests a clue for the early detection of pancreatic cancer.

AIMS: This study aimed to identify the pathological features of high-grade PanIN that presents with imaging-detectable abnormalities. METHODS AND RESULTS: Ten cases of isolated, main-duct, high-grade PanIN as the primary clinical presentation were identified. All patients presented with stenosis of the main pancreatic duct, with two being associated with extensive upstream duct dilatation (>5 mm in diameter). Pancreatic juice cytology suggested adenocarcinoma in all seven cases examined. In resected specimens, high-grade PanIN was present chiefly in the main pancreatic duct, with longitudinal extension ranging between 3 and 40 mm in length (median = 18 mm). In four cases, in which hypoechoic or hypovascular masses were observed on imaging, radiopathology correlations suggested that they represented parenchymal atrophy and subsequent fibrosis around affected ducts, but not invasive malignancy. On immunohistochemistry, the loss of p16 expression was found in five (50%), p53 overexpression in two (20%) and loss of SMAD4 expression in none (0%). KRAS mutations were detected in nine cases, with two dominant clones being found in three by ultrasensitive droplet digital polymerase chain reaction, suggesting the genetic heterogeneity of dysplastic cells composing individual lesions. Mutant GNAS was also observed in one case. CONCLUSIONS: Isolated high-grade PanIN may present with pancreatic duct stenosis. Therefore, intensive investigations including pancreatic juice cytology will be required for patients with unexplained pancreatic duct stenosis. The abnormal expression of p53 and SMAD4 is infrequent, while GNAS may be mutated in premalignant lesions mainly affecting the main pancreatic duct, similar to KRAS.

Clinicopathological characteristics of serum amyloid A-positive hepatocellular neoplasms/nodules arising in alcoholic cirrhosis.

AIMS: To characterize serum amyloid A (SAA)-positive hepatocellular neoplasms/nodules arising in alcoholic cirrhosis, which are detected as hypervascular hepatocellular nodules resembling hepatocellular carcinoma on imaging. METHODS AND RESULTS: Fifty-three hepatocellular nodules were examined with immunostaining for SAA, glutamine synthetase and glypican-3 in 23 patients (four women and 19 men) with alcoholic cirrhosis. Sixteen nodules were examined with magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid enhancement (EOB-MRI). Somatic mutations in IL6ST, GNAS and STAT3 were examined in 19 nodules. Thirty-six nodules in 18 patients were diagnosed as SAA-positive hepatocellular neoplasms/nodules, and the remaining 17 nodules in eight patients were SAA-negative focal nodular hyperplasia (FNH)-like nodules. SAA-positive hepatocellular neoplasms/nodules showed significantly more extensive sinusoidal dilatation, inflammatory reaction, abnormally thick arteries and cellular atypia than FNH-like nodules (P < 0.05). Eight SAA-positive hepatocellular neoplasms/nodules (67%) showed slight hypointensity in the hepatobiliary phase on EOB-MRI, whereas all four FNH-like nodules showed iso-intensity (P < 0.05). STAT3 mutations were detected in two of 17 SAA-positive hepatocellular neoplasms/nodules. CONCLUSIONS: This study showed that approximately two-thirds of hypervascular hepatocellular nodules arising in alcoholic cirrhosis were SAA-positive hepatocellular neoplasms/nodules, which show different findings on the EOB-MRI. STAT3 mutations were detected in 11.8% of SAA-positive hepatocellular neoplasms/nodules, supporting a neoplastic nature.

A fatal case of progressive steatohepatitis, possibly chemotherapy-associated steatohepatitis related to gemcitabine.

We report the case of an 80-year-old female suffering from pancreatic cancer who developed severe non-alcoholic steatohepatitis (NASH) resulting in fatal hepatic failure after anti-cancer chemotherapy with gemcitabine. Hepatic encephalopathy appeared 1 year after the chemotherapy, and the patient developed progressive liver failure and eventually died. Radiological examination showed severe fatty liver. Histopathological examination of a liver needle necropsy showed almost panlobular macrovesicular fatty change. Ballooning degeneration and necrosis of hepatocytes accompanying neutrophil infiltration, Mallory bodies, and a few bile plugs were found in zone 3. Marked perivenular and pericellular/perisinusoidal fibrosis and extensive bridging fibrosis were also found. Together, these findings indicated steatohepatitis at a precirrhotic stage. Because the patient had no history of drinking in excess, we made a diagnosis of NASH, in particular, chemotherapy-associated steatohepatitis (CASH). Gemcitabine is a pyrimidine nucleoside antimetabolite with anti-cancer activity. A few reports have mentioned fatal hepatotoxicity caused by gemcitabine, but, to our knowledge, this is the first report of steatohepatitis, possibly associated with gemcitabine. Physicians treating patients with this drug should be aware of the possibility of steatohepatitis.

Characterization of CD133+ parenchymal cells in the liver: histology and culture.

AIM: To reveal the characteristics of CD133(+) cells in the liver. METHODS: This study examined the histological characteristics of CD133(+) cells in non-neoplastic and neoplastic liver tissues by immunostaining, and also analyzed the biological characteristics of CD133(+) cells derived from human hepatocellular carcinoma (HCC) or cholangiocarcinoma cell lines. RESULTS: Immunostaining revealed constant expression of CD133 in non-neoplastic and neoplastic biliary epithelium, and these cells had the immunophenotype CD133(+)/CK19(+)/HepPar-1(-). A small number of CD133(+)/CK19(-)/HepPar-1(+) cells were also identified in HCC and combined hepatocellular and cholangiocarcinoma. In addition, small ductal structures, resembling the canal of Hering, partly surrounded by hepatocytes were positive for CD133. CD133 expression was observed in three HCC (HuH7, PLC5 and HepG2) and two cholangiocarcinoma cell lines (HuCCT1 and CCKS1). Fluorescence-activated cell sorting (FACS) revealed that CD133(+) and CD133(-) cells derived from HuH7 and HuCCT1 cells similarly produced CD133(+) and CD133(-) cells during subculture. To examine the relationship between CD133(+) cells and the side population (SP) phenotype, FACS was performed using Hoechst 33342 and a monoclonal antibody against CD133. The ratios of CD133(+)/CD133(-) cells were almost identical in the SP and non-SP in HuH7. In addition, four different cellular populations (SP/CD133(+), SP/CD133(-), non-SP/CD133(+), and non-SP/CD133(-)) could similarly produce CD133(+) and CD133(-) cells during subculture. CONCLUSION: This study revealed that CD133 could be a biliary and progenitor cell marker in vivo. However, CD133 alone is not sufficient to detect tumor-initiating cells in cell lines.

Histological and culture studies with respect to ABCG2 expression support the existence of a cancer cell hierarchy in human hepatocellular carcinoma.

In this study, we examined the possible involvement of progenitor cells in the carcinogenesis of human hepatocellular carcinoma (HCC) using tissue specimens and cell lines. We used ATP-binding cassette transporter ABCG2 as a progenitor cell marker. Immunohistochemically, ABCG2(+) hepatocytes were observed in the periportal areas of the dysplastic nodule, and ABCG2(+) cancer cells were also scattered or focally clustered in HCC. We sorted the cultured HCC cells (HuH7 and PLC5) into ABCG2(+) and ABCG2(-) subpopulations and then subcultured them for 4 weeks. ABCG2(+) cells could generate ABCG2(+) and ABCG2(-) progenies during subculture, whereas ABCG2(-) cells bore only ABCG2(-) cells, suggesting that a cancer cell hierarchy with reference to ABCG2 exists in HCC cells and that ABCG2(+) cells reside at the higher rank in that hierarchy. Interestingly, other progenitor cell markers including cytokeratin 19 and alpha-fetoprotein were mainly expressed in ABCG2(+) subpopulations. Conversely, albumin expression was more intense in ABCG2(-) cells. In addition, the expression patterns of transcription factors (GATA6, CCAAT/enhancer-binding protein alpha, and CCAAT/enhancer-binding protein beta) in ABCG2(+) and ABCG2(-) cells resembled those during normal liver development. In conclusion, this study suggests that cancer cells with ABCG2 expression might play a central role in hepatocarcinogenesis and the maintenance of the cancer cell hierarchy of human HCC.