Morphologic and Molecular Findings in Myxoid Hepatic Adenomas

Myxoid hepatic adenomas are a rare subtype of hepatic adenomas with distinctive deposition of extracellular myxoid material between the hepatic plates. A total of 9 cases were identified in 6 women and 3 men with an average of 59±12 years. The myxoid adenomas were single tumors in 5 cases and multiple in 4 cases. In 1 case with multiple adenomas, the myxoid adenoma arose in the background of GNAS-mutated hepatic adenomatosis. Myxoid hepatic adenomas had a high frequency of malignant transformation (N=5 cases). They were characterized at the molecular level by HNF1A inactivating mutations, leading to loss of LFABP protein expression. In addition, myxoid adenomas had recurrent mutations in genes within the protein kinase A (PKA) pathway or in genes that regulate the PKA pathway: GNAS, CDKN1B (encodes p27), and RNF123. In sum, myxoid adenomas are rare, occur in older-aged persons, have a high risk of malignant transformation, and are characterized by the combined inactivation of HNF1A and additional mutations that appear to cluster in the PKA pathway.

Biopsy Specimens From Allograft Liver Contain Histologic Features of Hepatitis C Virus Infection After Virus Eradication

BACKGROUND & AIMS

Most patients, even those who have received a liver transplant, achieve a sustained virologic response (SVR) to therapy for hepatitis C virus (HCV) infection. Little is known about the histologic features of liver biopsy specimens collected after SVR, particularly in patients who have received a liver transplant. We aimed to better characterize the histologic features of allograft liver biopsy specimens from patients who achieved SVR to anti-HCV therapy after liver transplantation.

METHODS

We performed a retrospective analysis of 170 allograft liver biopsy specimens from 36 patients who received a liver transplant for chronic HCV infection, had recurrent HCV infection after transplantation, and subsequently achieved SVR (collected from 1999 through 2015 at 4 medical centers). SVR was defined as an undetectable serum HCV RNA level 24 weeks after completion of HCV treatment. A total of 65 biopsy specimens were post-SVR (at least 1 post-SVR from each patient; some biopsy specimens were collected at later time points from a subset of patients). We performed polymerase chain reaction analysis for HCV RNA on a subset of the biopsy specimens (28 collected before SVR and 32 after SVR).

RESULTS

Of the 65 post-SVR biopsy specimens, 45 (69%) had histologic features of active HCV infection. Of the initial post-SVR biopsy specimens collected from each of the 36 patients, 32 (89%) showed these changes. For patients with more than 1 post-SVR biopsy specimen, 6 (46%) had no change in fibrosis between biopsies, and fibrosis worsened for 3 patients (23%) based on their most recent biopsy. The HCV RNA level was undetectable in 31 of the 32 biopsy specimens analyzed by polymerase chain reaction.

CONCLUSIONS

In a retrospective analysis of allograft liver biopsy specimens from patients who achieved SVR after a liver transplant for chronic HCV infection, histologic changes associated with active HCV were present in 69% and fibrosis continued to progress in 23%, despite the lack of detection of HCV RNA. Pathologists should be aware of patients' SVR status when analyzing liver biopsy specimens to avoid diagnoses of chronic HCV-associated hepatitis. Because of the persistent inflammatory activity and fibrosis after SVR, clinicians should continue to monitor patients carefully after SVR to anti-HCV therapy.

Mass-spectrometry-based quantitation of Her2 in gastroesophageal tumor tissue: comparison to IHC and FISH

BACKGROUND

Trastuzumab has shown a survival benefit in cases of Her2-positive gastroesophageal cancer (GEC). Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) currently determine eligibility for trastuzumab-based therapy. However, these low-throughput assays often produce discordant or equivocal results.

METHODS

We developed a targeted proteomic assay based on selected reaction monitoring mass spectrometry (SRM-MS) and quantified levels (amol/μg) of Her2-SRM protein in cell lines (n = 27) and GEC tissues (n = 139). We compared Her2-SRM protein expression with IHC/FISH, seeking to determine optimal SRM protein expression cutoffs in order to identify HER2 gene amplification.

RESULTS

After demonstrating assay development, precision, and stability, Her2-SRM protein measurement was observed to be highly concordant with the HER2/CEP17 ratio, particularly in a multivariate regression model adjusted for SRM expression of the covariates Met, Egfr, Her3, and HER2 heterogeneity, as well as their interactions (cell lines r (2) = 0.9842; FFPE r (2) = 0.7643). In GEC tissues, Her2-SRM protein was detected at any level in 71.2 % of cases. ROC curves demonstrated that Her2-SRM protein levels have a high specificity (100 %) at an upper-level cutoff of >750 amol/µg and sensitivity of 75 % at a lower-level cutoff of <450 amol/μg for identifying HER2 FISH-amplified tumors. An "equivocal zone" of 450-750 amol/µg of Her2-SRM protein was analogous to IHC2+ but represented fewer cases (9-16 % of cases versus 36-41 %).

CONCLUSIONS

Compared to IHC, targeted SRM-Her2 proteomics provided more objective and quantitative Her2 expression with excellent HER2/CEP17 FISH correlation and fewer equivocal cases. Along with its multiplex capability for other relevant oncoproteins, these results demonstrate a refined HER2 protein expression assay for clinical application.

Safety and efficacy of EMR for sporadic, nonampullary duodenal adenomas: a single U.S. center experience (with video)

BACKGROUND AND AIMS

EMR is increasingly used for resection of sporadic, nonampullary duodenal adenomas (SNDAs), but there are no guidelines for the management of these lesions. The aims of this study were to evaluate the safety and efficacy of EMR exclusively for SNDAs and to determine the factors predictive of outcomes.

METHODS

We performed a retrospective review of patients with SNDAs referred for endoscopic therapy from 2006 to 2013. The outcomes studied were successful endoscopic resection, major adverse events, early and late recurrences, and clinical remission.

RESULTS

Sixty-eight patients with SNDAs were included and 51 (75%) underwent EMR. The mean adenoma size was 22.0 ± 8.9 mm. Successful resection was achieved in 49 of 51 patients (96.1%), and major adverse events were noted in 8 of 51 patients (15.7%). Early and late recurrences were noted in 25.6% and 5.2% of patients, respectively, and were treated endoscopically. Clinical remission was achieved in 89.7% of patients after a median follow-up of 15 months. Presence of villous histology was associated with increased recurrence (P = .019), but no association of recurrence was noted with other endoscopic features or resection technique. Large adenoma size (P = .0057) and need for intraprocedural hemostasis (P = .006) were associated with increased adverse events, but no association of adverse events was noted with location or resection technique.

CONCLUSIONS

Large duodenal adenomas can be effectively managed with EMR at a referral center with experienced endoscopists. However, EMR has a significant recurrence rate, especially early recurrence, and the risk of adverse events is not negligible. Endoscopic therapy is successful in managing recurrent adenomas.

Her2 expression in gastroesophageal cancer (GEC) FFPE tissue using mass spectrometry (MS) and correlation with HER2 gene amplification

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Background: HER2+ GEC derived benefit from trastuzumab. Her2 IHC is semi-quantitative, subjective, and sensitive to antigen instability; HER2 FISH is laborious, expensive, and subjective. False positivity/negativity have been described. Also, these are low throughput assays; there is known molecular heterogeneity, with several putative biomarkers, and only scarce tissue to assess for each. We sought to evaluate the association of Her2 MS expression with HER2 FISH, along with other markers within the ‘GEC-plex’. Methods: We utilized a previously described unique Her2 peptide and quantification method (Hembrough et al J Clin Oncol 32,2014(suppl 3;abstr17)). The assay was run on 27 cell lines, in parallel with HER2:CEP17 FISH. Her2 expression thresholds were established for HER2 amplification using ROC curves. We adjusted for Her3, Egfr, and Met MS expression levels and sample HER2:CEP17 ratio heterogeneity in a multiple linear regression model. The model/cut-offs were then validated prospectively on GEC tissues (n=142). Results: Her2 MS on cell lines revealed concordance with FISH (HER2:CEP17) ratio (R2=0.75), which improved by adjusting for Her3 MS, Egfr MS, Met MS and HER2:CEP17 heterogeneity (R2>0.98), with significant interactions. IHC correlation with HER2:CEP17 ratio was poor (R2=0.12). A wide range of expression was noted within IHC3+ patients (<150-24671amol/ug). Her2 MS expression (>150 amol/ug) was seen in 72.9% (102/142) of tissues (range <150-24671amol/ug); 9.9% (14/142) had Her2 > 750 amol/ug - all were HER2 FISH amplified. 6/142 (4%) cases <500 amol/ug were clinically ‘HER2amplified’. IHC/FISH results for cases with 550-750 amol/ug demonstrated an ‘equivocal’ zone, not unlike ‘IHC 2+’, but less frequent (8/142, 5.6% vs 46/142 32.4%). Conclusions: The MS HER2 assay can be multiplexed with other GEC biomarkers. A robust model was developed that showed strong correlation of Her2 MS with HER2:CEP17 ratio, particularly when adjusting for covariates Egfr MS, Met MS, Her3 MS, and HER2 FISH heterogeneity. Future analysis will assess the established model as a tool for better prediction of therapeutic benefit from anti-Her2 therapy compared to current methods.

Crohn enteritis-associated small bowel adenocarcinomas exhibit gastric differentiation

Primary small bowel adenocarcinoma is rare. Although generally similar to colonic adenocarcinoma, some small bowel adenocarcinomas exhibit unique morphologic features, particularly those arising in association with Crohn disease. In this study, 15 sporadic small bowel adenocarcinomas and 11 Crohn enteritis-associated small bowel adenocarcinomas were examined for histology and immunohistochemical profile including cytokeratins (CK) 7 and 20, intestinal markers CDX2 and MUC2, and gastric epithelial markers MUC5AC and MUC6. We found that Crohn enteritis-associated small bowel adenocarcinomas frequently resemble gastric tubular adenocarcinoma histologically. In addition, when compared to sporadic small bowel adenocarcinoma, the former expressed MUC5AC and MUC6 with much higher frequency (82% vs. 7% and 73% vs. 0%, respectively). Ten of 11 Crohn enteritis-associated small bowel adenocarcinomas (91%) were positive for at least one gastric-type marker (MUC5AC or MUC6). Expression of CK7 was also more frequent in Crohn enteritis-associated small bowel adenocarcinoma (73% versus 27%) while expression of CK20 was less frequent (64% vs. 100%). There was no difference between sporadic and Crohn enteritis-associated small bowel adenocarcinoma in expression of CDX2 (100% vs. 91%) and MUC2 (93% vs. 73%). These observations suggest that there is a difference in the morphologic and immunohistochemical characteristics of sporadic versus Crohn enteritis-associated small bowel adenocarcinoma, particularly in their expression of gastric-type mucin. The findings also suggest that gastric differentiation in Crohn enteritis-associated small bowel adenocarcinoma is related to gastric metaplasia, a common phenomenon in Crohn disease.

Initial experience with transvaginal incisional hernia repair

INTRODUCTION

Natural orifice surgery has evolved from a preclinical setting into a common occurrence at the University of California San Diego (UCSD). With close to 40 transvaginal cases, we have become comfortable with this technique and are exploring other indications. One of the perceived advantages in natural orifice surgery is the potential reduction in the incidence of hernia formation. Patients with abdominal wall hernias may be at increased risk of forming additional hernias at incision sites. In addition, patients with recurrent incisional hernias may, likewise, be at increased risk. We believe that reducing or eliminating abdominal wall incisions may be of benefit in the repair of abdominal wall hernias. Here, we describe what we believe to be the first natural orifice transluminal endoscopic surgical (NOTES) approach to the repair of an abdominal wall hernia.

METHODS

The patient is a 38-year-old female with a painful recurrent umbilical hernia, previously repaired 8 years prior with a polypropylene-based mesh. The patient underwent a transvaginal recurrent umbilical hernia repair with one other 5-mm port in the abdomen for safety.

RESULTS

The patient had no intraoperative or postoperative complications. At 5 months follow up, the patient had no complaints, no evidence of hernia recurrence, and was very pleased with her result.

CONCLUSIONS

The repair of primary and incisional hernias of the ventral abdominal wall via a transvaginal approach is technically feasible, and the result of our initial case was exceptional. However, there are still significant obstacles which must be addressed before this approach can be widely utilized. These obstacles include safe entrance into the abdominal cavity via a transvaginal approach, the proper mesh to be placed during the repair, and the risk of infection.

Does weight loss improve incontinence in moderately obese women?

The aim of this study was to evaluate the effect of weight reduction on urinary incontinence in moderately obese women. This prospective cohort study enrolled moderately obese women experiencing four or more incontinence episodes per week. BMI and a 7-day urinary diary were collected at baseline and on the completion of weight reduction. The study included 10 women with a mean (+/-SD) baseline BMI of 38.3 (+/-10.1) kg/m2 and 13 (+/-10) incontinent episodes per week. Participants had a mean BMI reduction of 5.3 (+/-6.2) kg/ m2 (P < 0.03). Among women achieving a weight loss of > or = 5%, 6/6 had > or = 50% reduction in incontinence frequency compared to 1 in 4 women with < 5% weight loss (P < 0.03). Incontinence episodes decreased to 8 (+/-10) per week following weight reduction (P < 0.07). The study demonstrated an association between weight reduction and improved urinary incontinence. Weight reduction should be considered for moderately obese women as part of non-surgical therapy for incontinence.

Effect of paraoxon on erythrocyte metabolism as measured by oxygen uptake in vitro

1. Oxygen consumption in vitro and persistence in the general circulation of rabbit erythrocytes treated with the cholinesterase inhibitor paraoxon were determined.2. Paraoxon in vitro reduced oxygen consumption below a measureable level within 2 hours. By contrast, the metabolic inhibitor N-ethylmaleimide (NEM) produced complete inhibition within 15 minutes.3. Erythrocytes from rabbits orally dosed with parathion also exhibited marked depression of oxygen consumption.4. Glutathione (GSH) restored oxygen uptake to pretreatment levels within 15 min in erythrocytes previously inhibited with NEM or paraoxon.5. Erythrocytes treated with NEM were rapidly removed from the general circulation while paraoxon treated cells were removed at a rate comparable to untreated cells.