Gastric Plexiform Fibromyxoma: A Great Mimic of Gastrointestinal Stromal Tumor (GIST) and Diagnostic Pitfalls.

Through a multicenter study, we collected seven cases of gastric plexiform fibromyxoma including four females and three males, 21 to 79 y old (46.1 ± 10.1). All cases showed a unilocular lesion measuring 0.3 to 17 cm (5.3 ± 2.4), arising from antrum (5/7) or body (2/7). Six of the seven cases had intraoperative frozen sections and/or endoscopic ultrasound fine needle aspiration (EUS-FNA), and all of them were preoperatively or intraoperatively diagnosed as gastrointestinal stromal tumor (GIST). EUS-FNA material showed markedly elongated spindle cells with streaming oval to elongated nuclei with rounded ends. Histologically, the tumors exhibited a plexiform growth pattern and were composed of a rich myxoid stroma and cytologically bland uniform spindle cells without mitotic figures, with the exception of one case which displayed nuclear pleomorphism and increased mitosis. Immunostains showed the tumor cells to be focally positive for SMA (6/6), focally and weakly positive for desmin (3/6) and caldesmon (2/3), negative for CD117 (0/7), CD34 (0/7), DOG1 (0/4), and S100 (0/5). No mutations were identified on Next-Generation Sequencing test, and no loss of SDHB immunoreactivity was identified in the tumor with nuclear pleomorphism. One case was treated with Gleevec because of the initial diagnosis of GIST. All patients had a follow-up for up to 11 y, with no tumor recurrence or metastasis reported. Our results suggest that gastric plexiform fibromyxoma is rare and may be underrecognized and misinterpreted as GIST during intraoperative frozen section or preoperative EUS-FNA diagnosis without immunostains leading to inappropriate treatment.

Isolation of Pancreatic Cancer Cells from a Patient-Derived Xenograft Model Allows for Practical Expansion and Preserved Heterogeneity in Culture.

Commercially available, highly passaged pancreatic cancer (PC) cell lines are of limited translational value. Attempts to overcome this limitation have primarily consisted of cancer cell isolation and culture directly from human PC specimens. However, these techniques are associated with exceedingly low success rates. Here, we demonstrate a highly reproducible culture of primary PC cell lines (PPCLs) from patient-derived xenografts, which preserve, in part, the intratumoral heterogeneity known to exist in PC. PPCL expansion from patient-derived xenografts was successful in 100% of attempts (5 of 5). Phenotypic analysis was evaluated with flow cytometry, immunofluorescence microscopy, and short tandem repeat profiling. Importantly, tumorigenicity of PPCLs expanded from patient-derived xenografts was assessed by subcutaneous injection into nonobese diabeteic.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ mice. Morphologically, subcutaneous injection of all PPCLs into mice yielded tumors with similar characteristics to the parent xenograft. PPCLs uniformly expressed class I human leukocyte antigen, epithelial cell adhesion molecule, and cytokeratin-19. Heterogeneity within each PPCL persisted in culture for the frequency of cells expressing the cancer stem cell markers CD44, CD133, and c-Met and the immunologic markers human leukocyte antigen class II and programmed death ligand 1. This work therefore presents a reliable method for the rapid expansion of primary human PC cells and, thereby, provides a platform for translational investigation and, importantly, potential personalized therapeutic approaches.

Downstream mediators of the intratumoral interferon response suppress antitumor immunity, induce gemcitabine resistance and associate with poor survival in human pancreatic cancer.

The cancer microenvironment allows tumor cells to evade immune surveillance through a variety of mechanisms. While interferon-γ (IFNγ) is central to effective antitumor immunity, its effects on the microenvironment are not as clear and have in some cancers been shown to induce immune checkpoint ligands. The heterogeneity of these responses to IFNγ remains poorly characterized in desmoplastic malignancies with minimal inflammatory cell infiltration, such as pancreatic cancer (PC). Thus, the IFNγ response within and on key cells of the PC microenvironment was evaluated. IFNγ induced expression of human leukocyte antigen (HLA) class I and II on PC cell lines, primary pancreatic cancer epithelial cells (PPCE) and patient-derived tumor-associated stroma, concomitant with an upregulation of PDL1 in the absence of CD80 and CD86 expression. As expected, IFNγ also induced high levels of CXCL10 from all cell types. In addition, significantly higher levels of CXCL10 were observed in PC specimens compared to those from chronic pancreatitis, whereby intratumoral CXCL10 concentration was an independent predictor of poor survival. Immunohistochemical analysis revealed a subset of CXCR3-positive cancer cells in over 90 % of PC specimens, as well as on a subset of cultured PC cell lines and PPCE, whereby exposure to CXCL10 induced resistance to the chemotherapeutic gemcitabine. These findings suggest that IFNγ has multiple effects on many cell types within the PC microenvironment that may lead to immune evasion, chemoresistance and shortened survival.

Photoacoustic and fluorescence image-guided surgery using a multifunctional targeted nanoprobe.

PURPOSE: A complete surgical excision with negative tumor margins is the single most important factor in the prediction of long-term survival for most cancer patients with solid tumors. We hypothesized that image-guided surgery using nanoparticle-enhanced photoacoustic and fluorescence imaging could significantly reduce the rate of local recurrence. METHODS: A murine model of invasive mammary carcinoma was utilized. Three experimental groups were included: (1) control; (2) tumor-bearing mice injected with non-targeted nanoprobe; and (3) tumor-bearing mice injected with targeted nanoprobe. The surgeon removed the primary tumor following the guidance of photoacoustic imaging (PAI), then inspected the surgical wound and removed the suspicious tissue using intraoperative near-infrared (NIR) fluorescence imaging. The mice were followed with bioluminescence imaging weekly to quantify local recurrence. RESULTS: Nanoprobe-enhanced photoacoustic contrast enabled PAI to map the volumetric tumor margins up to a depth of 31 mm. The targeted nanoparticles provided significantly greater enhancement than non-targeted nanoparticles. Seven mice in the group injected with the targeted nanoprobes underwent additional resections based upon NIR fluorescence imaging. Pathological analysis confirmed residual cancer cells in the re-resected specimens in 5/7 mice. Image-guided resection resulted in a significant reduction in local recurrence; 8.7 and 33.3 % of the mice in the targeted and control groups suffered recurrence, respectively. CONCLUSIONS: These results suggest that photoacoustic and NIR intraoperative imaging can effectively assist a surgeon to locate primary tumors and to identify residual disease in real-time. This technology has promise to overcome current clinical challenges that result in the need for second surgical procedures.

Gene expression profiling of serrated polyps identifies annexin A10 as a marker of a sessile serrated adenoma/polyp.

Sessile serrated adenomas/polyps (SSA/Ps) are precursors of colon cancer, particularly those that exhibit microsatellite instability. Distinguishing SSA/Ps from the related, but innocuous, microvesicular hyperplastic polyp (MVHP) can be challenging. In this study seven gastrointestinal pathologists reviewed 109 serrated polyps and identified 60 polyps with histological consensus. Microarray analysis was performed on six distal consensus MVHPs < 9 mm, six proximal consensus SSA/Ps > 9 mm, and six normal colon biopsies (three proximal, three distal). Comparative gene expression analysis confirmed the close relationship between SSA/Ps and MVHPs as there was overlapping expression of many genes. However, the gene expression profile in SSA/Ps had stronger and more numerous associations with cancer-related genes compared with MVHPs. Three genes (TFF2, FABP6, and ANXA10) were identified as candidates whose expression can differentiate SSA/Ps from MVHPs, and the differences in expression were confirmed by quantitative RT-PCR. As ANXA10 showed the most promise in differentiating these polyps, the expression of ANXA10 was evaluated by immunohistochemistry in consensus SSA/Ps (n = 26), MVHPs (n = 21), and normal colon (n = 9). Immunohistochemical expression of ANXA10 was not identified in separate samples of normal colon or in the normal colonic epithelium adjacent to the serrated polyps. Consistent with the microarray and quantitative RT-PCR experiments, immunohistochemical expression of ANXA10 was markedly increased in SSA/Ps compared to MVHPs (p < 0.0001). An ANXA10 score ≥ 3 has a sensitivity of 73% and a specificity of 95% in the diagnosis of an SSA/P. In conclusion, we show that SSA/Ps and MVHPs have significant overlap in gene expression, but also important differences, particularly in cancer-related pathways. Expression of ANXA10 may be a potential marker of the serrated pathway to colon cancer.

Gastric and colonic metastases of malignant melanoma diagnosed during endoscopic evaluation of symptomatic anemia presenting as angina: a case report.

A 72-year-old man visited cardiology for exertional chest pain, lightheadedness, and fatigue. Six years prior, he was surgically treated for cutaneous malignant melanoma of the lower back. After a negative cardiac work-up, primary care diagnosed severe iron deficiency anemia. Emergent upper and lower gastrointestinal (GI) endoscopy revealed simultaneous melanoma metastases to the stomach and colon with discrete macroscopic features. Metastatic disease, including brain, lung, and bone, was discovered on imaging. Treatment included immunotherapy with nivolumab and stereotactic radiosurgery of the brain metastases, and our patient has remained in continued remission even after 2 years. Melanoma with GI tract (GIT) metastasis has a poor prognosis and rarely presents symptomatically or with synchronous gastric and colonic lesions. This case illustrates the importance of early primary care involvement to expedite work-up for multifocal GI metastases in patients with a remote melanoma history presenting with symptoms related to iron deficiency anemia (IDA).

Cytomegaloviral colitis in primary CMV viraemia in a young immunocompetent adult.

A man in his 20s presented with a 2-week history of fever, fatigue and diarrhoea. On arrival to the emergency department, he had clinical findings of sepsis. The care team initially suspected sepsis secondary to bacterial colitis and administered antibiotics. Further workup including a stool PCR assay for gastrointestinal pathogens failed to establish a diagnosis, and he had no evidence of immune compromise. Colonoscopy revealed mucosal ulceration presumed to be ulcerative colitis. Histopathology obtained after discharge revealed severe colitis with cytomegalovirus (CMV) inclusions. Serological studies indicated a primary CMV infection. To our knowledge, this is the first report of a primary CMV infection presenting as severe colitis and systemic disease in a young immunocompetent patient without underlying disease.

Unusual Presentation of Cow's Milk Protein Allergy.

Cow's milk protein allergy (CMPA) is an abnormal immunologic response to bovine protein that can result in various gastrointestinal and cutaneous manifestations including diarrhea, failure to thrive, malabsorption, and even protein-losing enteropathy. We describe a case of a 7-month-old breastfed male who presented with severe atopic dermatitis, emesis, oily diarrhea, failure to thrive, electrolyte disturbance, and hemodynamic instability. Following stabilization, additional evaluation revealed concern for abetalipoproteinemia. Ultimately, the patient's symptoms resolved with introduction of an elemental formula and returned with reinitiation of cow's milk protein, confirming the diagnosis of severe CMPA. It is important for the general practitioner to be aware of the various presentations and have a high index of suspicion for CMPA as no symptom or diagnostic test is pathognomonic for diagnosis. Even though it can mimic other causes of malabsorption, a trial with extensively hydrolyzed or elemental formula should be attempted before undertaking invasive testing.

Locoregional Therapy Protocols With and Without Radioembolization for Hepatocellular Carcinoma as Bridge to Liver Transplantation.

OBJECTIVE: The objective of this study was to compare posttransplant outcomes in patients undergoing bridging locoregional therapy (LRT) with Y-90 transarterial radioembolization (TARE) based protocol compared with transarterial chemoembolization based protocol for hepatocellular carcinoma (HCC) prior liver transplantation (LT). MATERIALS AND METHODS: Patients listed for LT with HCC within the Milan criteria at our center who had bridging LRT were treated according to transarterial chemoembolization (TACE) based protocol from May 2012 to April 2014 and a TARE based protocol from October 2014 to December 2017. Early posttransplant survival and tumor recurrence were compared between the groups. Tumor response to LRT, microvascular invasion (mVI), and the rate of delisting was also evaluated. RESULTS: One hundred three patients who were listed for LT with HCC within the Milan criteria received LRT. LT was performed in 65 patients, 28 treated with TARE protocol and 37 on TACE protocol. There were no statistical differences in baseline pretransplant characteristics and tumor recurrence. There was a trend toward improved 3-year survival in the TARE group (92.9% vs. 75.7%; P=0.052). The mVI was seen in 1/28 (3.6%) explants in the TARE group compared with 10/37 (27%) in the TACE group (P=0.013). The TARE group also required fewer LRT treatments (1.46 vs. 2.43; P=0.001) despite no difference in time on the transplant list. CONCLUSIONS: Despite requiring fewer LRT treatments, there was significantly less mVI in the explants of patients treated with TARE protocol LRT as a bridge to LT as well as a trend toward improved 3-year survival. Therefore, TARE may be associated with improved tumor control and reduced post-LT recurrence.

A Novel Small Molecule Inhibits Intrahepatocellular Accumulation of Z-Variant Alpha 1-Antitrypsin In Vitro and In Vivo.

Alpha 1-antitrypsin deficiency (AATD) is the most common genetic cause of liver disease in children and is associated with early-onset chronic liver disease in adults. AATD associated liver injury is caused by hepatotoxic retention of polymerized mutant alpha 1-antitrypsin molecules within the endoplasmic reticulum. Currently, there is no curative therapy for AATD. In this study, we selected small molecules with the potential to bind mutant alpha 1-antitrypsin (Z-variant) to inhibit its accumulation in hepatocytes. We used molecular docking to select candidate compounds that were validated in cell and animal models of disease. A crystal structure of polymerized alpha 1-antitrypsin molecule was used as the basis for docking 139,735 compounds. Effects of the top scoring compounds were investigated in a cell model that stably expresses Z-variant alpha 1-antitrypsin and in PiZ mice expressing Z-variant human alpha 1-antitrypsin (Z-hAAT), encoded by SERPINA1*E342K. 4','5-(Methylenedioxy)-2-nitrocinnamic acid was predicted to bind cleaved alpha 1-antitrypsin at the polymerization interface, and observed to co-localize with Z-hAAT, increase Z-hAAT degradation, inhibit intracellular accumulation of Z-hAAT, and alleviate liver fibrosis.

Desmoplasia and Detached Papillae in Early Esophageal Adenocarcinoma: A Histologic Study on Endoscopic Submucosal Dissection Specimens.

BACKGROUND: Desmoplasia and detached papillae were only rarely mentioned in intramucosal adenocarcinoma of esophagus or stomach. This study aimed to examine these two features in early esophageal adenocarcinoma. METHODS: All endoscopic submucosal dissections specimens performed for Barrett's esophagus neoplasm during the year 2013 to 2016 were reviewed. These 44 cases included in this study were eight Barrett's esophagus with high-grade dysplasia, 21 intramucosal adenocarcinoma, and 15 submucosally or beyond invasive adenocarcinoma. RESULTS: Desmoplasia occurred in 73% submucosally or beyond invasive adenocarcinoma, higher than intramucosal adenocarcinoma (24%) and high-grade dysplasia (0%) (P < 0.00001 for each). The frequency of detached papillae in intramucosal adenocarcinoma and submucosally or beyond invasive adenocarcinoma specimens was 71.4% and 73.3%, higher than high-grade dysplasia (0%, P < 0.0001 for both). Univariate analysis identified desmoplasia as risk factors for lymphovascular invasion in intramucosal adenocarcinoma specimens (odds ratio 12, P = 0.048), and desmoplasia and tumor thickness for lymphovascular invasion in intramucosal adenocarcinoma and submucosally or beyond invasive adenocarcinoma specimens combined (odds ratio 9.0, P = 0.005; odds ratio 2.7, P = 0.01, respectively). Age, gender, the largest dimension and the average thickness of endoscopic submucosal dissection specimens, tumor size, detached papillae, and poor differentiation were not associated with lymphovascular invasion (P ≥ 0.05 for all). Multivariate analysis confirmed that only desmoplasia was predictive of lymphovascular invasion (odds ratio 8.0, P = 0.02) in intramucosal adenocarcinoma and submucosally or beyond invasive adenocarcinoma specimens combined. CONCLUSIONS: In conclusion, desmoplasia occurs in about a quarter of esophageal intramucosal adenocarcinomas and three quarters of submucosally or beyond invasive adenocarcinomas, and is associated with lymphovascular invasion in early esophageal adenocarcinoma.

Risk factors for colorectal neoplasia in patients with underlying inflammatory bowel disease: a multicenter study.

BACKGROUND: This study sought to evaluate the risk factors for the development of colitis-associated neoplasia (CAN) in Chinese patients with inflammatory bowel disease (IBD). METHODS: IBD patients who developed CAN between 1999 and 2016 were identified from eight medical centers. In addition to initial pathology evaluation, a CAN diagnosis was confirmed by two expert pathologists. Patients with CAN (n = 29) were compared with non-CAN controls (n = 87). Matching was performed for gender and IBD type with a ratio of three controls to one subject. RESULTS: Of the 29 patients with CAN, 8 (27.6%) had colorectal cancer (CRC), 20 (69.0%) had a final diagnosis of low-grade dysplasia and 1 (3.4%) had high-grade dysplasia. Multivariate analysis revealed that an older age at the time of IBD diagnosis and a longer IBD duration were independent risk factors for the development of CAN, with odds ratios of 1.09 [95% confidence interval (CI): 1.04-1.14, P < 0.001] and 1.14 (95% CI: 1.03-1.27, P = 0.013), respectively. Comparison between IBD patients with CRC and those with dysplasia indicated that the former were older at the time of IBD diagnosis (P = 0.012) and had longer IBD durations (P = 0.019). CONCLUSIONS: Older age at the time of IBD diagnosis and longer IBD duration were found to be associated with the development of CAN in IBD patients.

Steatohepatitic Variant of Hepatocellular Carcinoma: A Focused Review.

The incidence of hepatocellular carcinoma (HCC) has steadily increased over the past three decades and currently ranks as the fifth most common cancer worldwide. Likewise, non-alcoholic fatty liver disease (NAFLD), a known risk factor for the development of HCC, has emerged as the most common liver disease in Western countries. The underlying pathogenesis of NAFLD-related HCC remains unclear. The steatohepatitic variant of HCC (SH-HCC) typically presents in patients with metabolic risk factors and either cirrhotic or non-cirrhotic NAFLD and shares many of the histological features found in non-alcoholic steatohepatitis (NASH). Given their similar morphological features, distinguishing SH-HCC from background fatty liver can be a diagnostic challenge. Immunohistochemical studies to characterize and assist in the diagnosis are relatively limited. Whether the steatotic phenotype of SH-HCC results from the tumor's adaptive response to an environment rich in fatty acids or from an independent pathogenic pathway remains to be seen. This review aims to summarize what is currently known regarding the pathogenesis and clinicopathological features of SH-HCC.

A case of extensive hepatic adenomatosis in a renal transplant patient.

Hepatic adenomatosis (HA) is a rare condition that is traditionally associated with oral contraceptive use, glycogen storage diseases or metabolic syndrome. Here we present a renal transplant recipient that was diagnosed with HA and has none of the traditional risk factors. We review the literature on diagnosing and managing HA.

Stroma-derived extracellular vesicles deliver tumor-suppressive miRNAs to pancreatic cancer cells.

The biology of tumor-associated stroma (TAS) in pancreatic ductal adenocarcinoma (PDAC) is not well understood. The paradoxical observation that stroma-depletion strategies lead to progression of PDAC reinforced the need to critically evaluate the functional contribution of TAS in the initiation and progression of PDAC. PDAC and TAS cells are unique in their expression of specific miRNAs, and this specific miRNA expression pattern alters host to tumor microenvironment interactions. Using primary human pancreatic TAS cells and primary xenograft PDAC cells co-culture, we provide evidence of miRNA trafficking and exchanging between TAS and PDAC cells, in a two-way, cell-contact independent fashion, via extracellular vesicles (EVs) transportation. Selective packaging of miRNAs into EVs led to enrichment of stromal specific miR-145 in EVs secreted by TAS cells. Exosomes, but not microvesicles, derived from human TAS cells demonstrated a tumor suppressive role by inducing PDAC cell apoptosis. This effect was mitigated by anti-miR-145 sequences. Our data suggest that TAS-derived miRNAs are delivered to adjacent PDAC cells via exosomes and suppress tumor cell growth. These data highlight that TAS cells secrete exosomes carrying tumor suppressive genetic materials, a possible anti-tumor capacity. Future work of the development of patient-derived exosomes could have therapeutic implications for unresectable PDAC.

Medicina prepagada: problemas bioéticos evidentes en la atención de sus pacientes / Prepaid medicine: Evident bioethical problems in patient care

El sistema de salud en Colombia hace parte del Sistema de Seguridad Social Integral (SGSS) creado por la Ley 100 de 1993. La medicina prepagada existe como un contrato comercial de seguro de personas desde antes del SGSS, para mejorar la comodidad y el lujo, con libertad de elección de profesionales, sin trámites burocráticos para autorizaciones, oportunidad de citas, resolución rápida, eficiencia por ahorro en tiempo, dinero, efectividad y calidad en la atención. La naturaleza del vínculo comercial da pie para que los usuarios puedan tomar ventaja ilegítima del contrato y cambien las relaciones de poder y líneas de autoridad, amparados por el derecho que sienten que les confiere la compra con el fin de ver su inversión en resultados. Se generan así relaciones no idóneas, que transforman la relación médico-paciente, dando lugar a toda clase de conflictos, perversiones y vicios con consecuencias nefastas desde el punto de vista clínico, bioético y jurídico. El caso, analizado desde la metodología de análisis en ética clínica de Diego Gracia para resolver dilemas bioéticos, se aplica para hacer evidentes los conflictos y problemas bioéticos que surgieron en este contexto.

The health system in Colombia is part of the General Social Security System (GSSS) created by Law 100 of 1993. Prepaid medicine exists as a Personal Insurance Commercial Contract since before the SGSS, to improve comfort, luxury, with freedom of choice of professionals, without bureaucratic procedures for authorizations, opportunity for appointments, decisiveness, efficiency due to savings in time, money, effectiveness, and quality of care. The nature of the commercial relationship allows users to take illegitimate advantage of the contract and change the power relationships and lines of authority protected by the right they feel the purchase confers on them to see their investment in results. Inappropriate relationships are thus generated, which transform the doctor-patient relationship, giving rise to all kinds of conflicts, perversions, and vices with disastrous consequences from the clinical, bioethical and legal point of view. The case, analyzed from Diego Gracia's clinical ethics analysis methodology to resolve bioethical dilemmas, is applied to make evident the conflicts and bioethical problems that arose in this context.

The pancreatic tumor microenvironment drives changes in miRNA expression that promote cytokine production and inhibit migration by the tumor associated stroma.

The pancreatic adenocarcinoma (PDAC) microenvironment is largely comprised of fibrotic tumor associated stroma (TAS) that contributes to the lethal biology of PDAC. microRNA (miRNA) are small non-coding RNAs that regulate gene expression. We hypothesized that interactions between PDAC cells and TAS cells within the microenvironment modulate miRNA expression and thus, tumor biology. We observed that miR-205 and members of the miR-200 family (miR-200a, -200b, -200c, -141 and miR-429) were exclusively expressed in PDAC cells, consistent with an epithelial miRNA signature, while miR-145 and miR-199 family members (miR-199a and -199b) were solely expressed in TAS cells, consistent with a stromal miRNA signature. This finding was confirmed by qRT-PCR of RNA obtained by laser-capture microdissection of surgical specimens. Using an in vitro co-culture model, we further demonstrated regulation of miRNA expression by cell-cell contact. Forced expression in TAS cells of miR-200b/-200c and miR-205 to mimic these observed changes in miRNA concentrations induced secretion of GM-CSF and IP10, and notably inhibited migration. These data suggest interactions within the tumor microenvironment alter miRNA expression, which in turn have a functional impact on TAS.

Mucinous Cystadenoma: A Rare Hepatic Tumor in a Child.

Mucinous cystadenomas (MCAs) of the liver (also called hepatic biliary cystadenomas) are rare tumors that comprise about 5% of cystic masses of the liver in adults. These slow-growing lesions most commonly occur in middle-aged individuals, with a female sex predominance. Herein, we present a MCA in a 6-year-old male, one of only very few such cases described in the pediatric literature to date. Although MCAs are generally considered benign lesions, malignant transformation rarely occurs. The recurrence rate is high when partial cyst excision is performed. Therefore, complete surgical cyst resection with clinical follow-up, including imaging, is warranted.