James P. Grenert

Tumors of the Ampulla of Vater: Histopathologic Classification and Predictors of Survival

BACKGROUND The histology and clinical behavior of ampullary tumors vary substantially. We speculated that this might reflect the presence of two kinds of ampullary adenocarcinoma: pancreaticobiliary and intestinal. STUDY DESIGN We analyzed patient demographics, presentation, survival (mean followup 44 months), and tumor histology for 157 consecutive ampullary tumors resected from 1989 to 2006. Histologic features were reviewed by a pathologist blinded to clinical outcomes. Survival was compared using Kaplan-Meier/Cox proportional hazards analysis. RESULTS There were 33 benign (32 adenomas and 1 paraganglioma) and 124 malignant (118 adenocarcinomas and 6 neuroendocrine) tumors. One hundred fifteen (73%) patients underwent a Whipple procedure, 32 (20%) a local resection, and 10 (7%) a palliative operation. For adenocarcinomas, survival in univariate models was affected by jaundice, histologic grade, lymphovascular, or perineural invasion, T stage, nodal metastasis, and pancreaticobiliary subtype (p < 0.05). Size of tumor did not predict survival, nor did cribriform/papillary features, dirty necrosis, apical mucin, or nuclear atypia. In multivariate models, lymphovascular invasion, perineural invasion, stage, and pancreaticobiliary subtype predicted survival (p < 0.05). Patients with pancreaticobiliary ampullary adenocarcinomas presented with jaundice more often than those with the intestinal kind (p = 0.01) and had worse survival. CONCLUSIONS In addition to other factors, tumor type (intestinal versus pancreaticobiliary) had a major effect on survival in patients with ampullary adenocarcinoma. The current concept of ampullary adenocarcinoma as a unique entity, distinct from duodenal and pancreatic adenocarcinoma, might be wrong. Intestinal ampullary adenocarcinomas behaved like their duodenal counterparts, but pancreaticobiliary ones were more aggressive and behaved like pancreatic adenocarcinomas.

Dietary sucrose is essential to the development of liver injury in the methionine-choline-deficient model of steatohepatitis

Methionine-choline-deficient (MCD) diets cause steatohepatitis in rodents and are used to study the pathophysiology of fatty liver disease in human beings. The most widely used commercial MCD formulas not only lack methionine and choline but also contain excess sucrose and fat. The objective of this study was to determine whether dietary sucrose in the MCD formula plays a role in the pathogenesis of MCD-related liver disease. We prepared two custom MCD formulas, one containing sucrose as the principal carbohydrate and the other substituting sucrose with starch. Mice fed the sucrose-enriched formula developed typical features of MCD-related liver disease, including hepatic steatosis, hepatocellular apoptosis, alanine aminotransferase elevation, lipid peroxidation, and hepatic inflammation. In contrast, mice fed MCD-starch were significantly protected against liver injury. MCD-sucrose and MCD-starch mice displayed identical diet-related abnormalities in hepatic fatty acid uptake and triglyceride secretion. Hepatic de novo lipogenesis and triglyceride synthesis, however, were 2 times higher in MCD-sucrose mice than MCD-starch mice (P < 0.01). Hepatic lipid analysis revealed accumulation of excess saturated fatty acids in MCD-sucrose mice that correlated with hepatocellular injury. Overall, the results indicate that dietary sucrose is critical to the pathogenesis of MCD-mediated steatohepatitis. They suggest that saturated fatty acids, which are products of de novo lipogenesis, are mediators of hepatic toxicity in this model of liver disease.

Lack of Association of BRAF Mutation With Negative Prognostic Indicators in Papillary Thyroid Carcinoma: The University of California, San Francisco, Experience

IMPORTANCE Papillary thyroid carcinoma (PTC) is the most common endocrine neoplasm. B-type raf kinase (BRAF) V600E mutation has been proposed as a negative prognostic indicator in PTC, and patients harboring it should receive more aggressive initial therapy. OBJECTIVE To assess the significance of BRAF V600E mutation in PTC in the largest US sample to date. DESIGN We identified patients from our institutions pathology archives diagnosed as having PTC and meeting criteria for BRAF mutation testing. Medical records were analyzed for BRAF status (positive or negative) and a list of standardized clinicopathologic features. PARTICIPANTS A total of 429 patients with PTC at an academic medical center. MAIN OUTCOMES AND MEASURES Clinicopathologic features in patients with PTC with and without BRAF mutation. RESULTS Of 429 cases with PTC, 314 (73.2%) were positive for the BRAF mutation and 115 (26.8%) tested negative. BRAF mutation was significantly associated with tumor margin positivity (P = .03) and lymph node metastasis (P = .002) on univariate analysis but not on multivariate study. BRAF mutation was a predictor of male sex (odds ratio [OR], 3.2; 95% CI, 1.4-7.2), total thyroidectomy (OR, 2.6; 95% CI, 1.1-6.2), and a negative predictor of follicular variant PTC (OR, 0.1; 95% CI, 0.1-0.4). There was no significant association between BRAF positivity and tumor multicentricity, lymphovascular invasion, extranodal extension, central neck involvement, advanced stage (stage III or IV), and distant metastasis. CONCLUSIONS AND RELEVANCE BRAF V600E mutation has been extensively studied in relation to negative prognostic indicators in PTC, with no consistent relationship emerging. Two recent meta-analyses showed an overall association between BRAF status and aggressive disease features and called for tailoring treatment plans in patients accordingly. In this, the largest US study to date, BRAF status was not significantly associated with most clinicopathologic features suggestive of more aggressive disease.

Atypical hepatocellular adenoma–like neoplasms with β-catenin activation show cytogenetic alterations similar to well-differentiated hepatocellular carcinomas

The distinction of hepatocellular adenoma from well-differentiated hepatocellular carcinoma (HCC) arising in noncirrhotic liver can be challenging, particularly when tumors histologically resembling hepatocellular adenoma occur in unusual clinical settings such as in a man or an older woman or show focal atypical morphologic features. In this study, we examine the morphologic, immunohistochemical, and cytogenetic features of hepatocellular adenoma-like neoplasms occurring in men, women 50 years or older or younger than 15 years, and/or those with focal atypia (small cell change, pseudogland formation, and/or nuclear atypia), designated atypical hepatocellular neoplasms, where the distinction of hepatocellular adenoma versus HCC could not be clearly established. Immunohistochemistry was performed for β-catenin, glutamine synthetase, and serum amyloid A in 31 hepatocellular adenomas, 20 well-differentiated HCCs, and 40 atypical hepatocellular neoplasms. Chromosomal gains/losses had previously been determined in 37 cases using comparative genomic hybridization or fluorescence in situ hybridization. β-Catenin activation was observed in 35% of atypical hepatocellular neoplasms compared with 10% of typical hepatocellular adenomas (P < .05) and 55% of well-differentiated HCCs (P = .14). Cytogenetic changes typically observed in HCC were present in all atypical hepatocellular neoplasms with β-catenin activation. β-Catenin activation in atypical hepatocellular neoplasms was also associated with atypical morphologic features. Follow-up data were limited, but adverse outcome was observed in 2 atypical hepatocellular neoplasms with β-catenin activation (1 recurrence, 1 metastasis); transition to areas of HCC was observed in 1 case. The similarity in morphologic and cytogenetic features of β-catenin-activated hepatocellular adenoma-like tumors and HCC suggests that the former tumors represent an extremely well-differentiated variant of HCC.

Persistent systemic inflammation and atypical enterocolitis in patients with NEMO syndrome

The NEMO syndrome is a primary immunodeficiency with immune and non-immune manifestations. The immune deficiency is heterogeneous showing defects in humoral, innate, and cell-mediated immunity. While the clinical aspects of the immunodeficiency are increasingly well understood, little is known about autoimmune manifestations in NEMO patients. We therefore sought to examine serologic markers of systemic inflammation and intestinal pathology in a kindred of patients with the NEMO syndrome. We observed persistent elevation of erythrocyte sedimentation rates in five patients, and two were symptomatic, with a chronic but atypical enterocolitis. Though pathologic lesions in these two patients were consistent with acute inflammation, sustained clinical improvement was only achieved with systemic and/or topical glucocorticoid therapy. Our data suggest that some patients with the NEMO syndrome exhibit persistent elevation of inflammatory markers similar to systemic autoimmune diseases and may subsequently develop an atypical enterocolitis.

PAX2 distinguishes benign mesonephric and mullerian glandular lesions of the cervix from endocervical adenocarcinoma, including minimal deviation adenocarcinoma.

Mesonephric remnants of the cervix are vestiges of the embryonic mesonephric system which typically regresses during female development. Uncommonly, hyperplasia of the mesonephric remnants may occur. The differential diagnosis of exuberant mesonephric hyperplasia includes minimal deviation adenocarcinoma of the cervix, a tumor with deceptively bland morphology for which no reliable diagnostic biomarkers currently exist. PAX2 encodes a transcription factor necessary in the development of the Wolffian duct system, and the protein is expressed in several tumors of mesonephric origin, including renal cell carcinoma, Wilm tumor, and nephrogenic adenoma. We hypothesized that PAX2 may also be expressed in mesonephric lesions of the cervix and may distinguish mesonephric hyperplasia from minimal deviation adenocarcinoma of the cervix. We demonstrated that PAX2 was strongly and diffusely expressed in mesonephric remnants (6 of 6) and in mesonephric hyperplasia (18 of 18); however, no expression was noted in mesonephric adenocarcinoma (0 of 1). PAX2 was expressed in normal endocervical glands (including tunnel clusters and Nabothian cysts) (86 of 86), lobular endocervical glandular hyperplasia (5 of 5), tubal/tuboendometrioid metaplasia (8 of 8), and cervical endometriosis (13 of 14). In contrast, only 2 cases of endocervical adenocarcinoma were positive for PAX2 [invasive adenocarcinoma of the minimal deviation type (0 of 5), usual type (1 of 22), and endometrioid type (1 of 1)]. Adjacent adenocarcinoma in situ, as well as cases of pure adenocarcinoma in situ (0 of 6), were also PAX2 negative. PAX2 expression in the 2 positive endocervical adenocarcinomas was patchy and weak. Most (11 of 15) stage II endometrial endometrioid adenocarcinomas lacked PAX2 expression but 1 of 10 grade 1 tumors and 3 of 5 grade 2 tumors did express PAX2. These results suggest that PAX2 immunoreactivity may be useful to (1) distinguish mesonephric hyperplasia from minimal deviation adenocarcinoma, (2) to distinguish lobular endocervical glandular hyperplasia from minimal deviation adenocarcinoma, and (3) to distinguish endocervical tubal metaplasia or cervical endometriosis from endocervical adenocarcinoma in situ. Overall, a strong, diffuse nuclear PAX2 expression pattern in a cervical glandular proliferation predicts a benign diagnosis (positive predictive value 90%, negative predictive value 98%; P<0.001); however, PAX2 should not be interpreted in isolation from the architectural and cytologic features of the lesion as it may be expressed in some stage II endometrial adenocarcinomas involving the cervix.

Epidermal growth factor receptor and HER-2/neu status by immunohistochemistry and fluorescence in situ hybridization in adenocarcinomas of the biliary tree and gallbladder

Adenocarcinomas of the biliary tract and gallbladder are aggressive tumors with a poor prognosis. Standard chemotherapy often offers minimal benefit. Because epidermal growth factor receptor and HER-2/neu antagonists have been successfully used in adenocarcinomas from other sites, their use in cholangiocarcinoma can be potentially beneficial. This study examines the epidermal growth factor receptor and HER-2/neu expression and the epidermal growth factor receptor gene copy number in biliary tract adenocarcinomas. Fifty-one formalin-fixed, paraffin-embedded cases of adenocarcinomas (26 intrahepatic, 19 extrahepatic, 6 gallbladder) were stained with monoclonal antibodies against epidermal growth factor receptor and HER-2/neu. Fluorescence in situ hybridization analysis was performed in 37 cases using probes directed against epidermal growth factor receptor and centromeric region of chromosome 7. Epidermal growth factor receptor expression was present in 41 (80%) cases, with moderate or strong epidermal growth factor receptor staining in 30 (59%) cases. HER-2/neu was positive in 2 (4%) cases. Fluorescence in situ hybridization analysis showed gain in epidermal growth factor receptor gene copy number in 17 (46%) tumors. Of the latter, 1 showed gene amplification, whereas all others showed gain in chromosome 7, indicating balanced polysomy. Epidermal growth factor receptor overexpression by immunohistochemistry correlated significantly with epidermal growth factor receptor copy number by fluorescence in situ hybridization (P = .02). HER2/neu expression is uncommon in these tumors.

Stress Signaling in the Methionine-Choline–Deficient Model of Murine Fatty Liver Disease

BACKGROUND & AIMS Stress signaling, both within and outside the endoplasmic reticulum, has been linked to metabolic dysregulation and hepatic steatosis. Methionine-choline-deficient (MCD) diets cause severe fatty liver disease and have the potential to cause many types of cellular stress. The purpose of this study was to characterize hepatic stress in MCD-fed mice and explore the relationship between MCD-mediated stress and liver injury. METHODS Stress signaling was examined in mice fed MCD formulas for 4-21 days. Signaling also was evaluated in mice fed MCD formulas supplemented with clofibrate, which inhibits hepatic triglyceride accumulation. The role of the pro-apoptotic stress protein C/EBP homologous protein (CHOP) in MCD-mediated liver injury was assessed by comparing the responses of wild-type and CHOP-deficient mice to an MCD diet. RESULTS MCD feeding caused steatohepatitis coincident with the activation of cJun N-terminal kinase and caspase-12. In contrast, MCD feeding did not activate inositol-requiring protein-1 and actually suppressed the expression of X-box protein-1s. MCD feeding caused weak stimulation of double-stranded RNA-activated protein kinase-like endoplasmic reticulum-resident kinase, but robust activation of general control nonderepressible-2, followed by the phosphorylation of eukaryotic initiating factor-2α and induction of CHOP. Clofibrate eliminated MCD-mediated hepatic steatosis but did not inhibit diet-induced stress. CHOP deficiency did not alleviate, and in fact worsened, MCD-mediated liver disease. CONCLUSIONS MCD feeding causes an integrated stress response in the liver rather than a classic unfolded protein response. This stress response does not by itself lead to liver injury. CHOP, despite its identity as a mediator of stress-related cell death, does not play a central role in the pathogenesis of MCD-mediated liver disease.

Targeted next-generation sequencing of pediatric neuro-oncology patients improves diagnosis, identifies pathogenic germline mutations, and directs targeted therapy

Background Molecular profiling is revolutionizing cancer diagnostics and leading to personalized therapeutic approaches. Herein we describe our clinical experience performing targeted sequencing for 31 pediatric neuro-oncology patients. Methods We sequenced 510 cancer-associated genes from tumor and peripheral blood to identify germline and somatic mutations, structural variants, and copy number changes. Results Genomic profiling was performed on 31 patients with tumors including 11 high-grade gliomas, 8 medulloblastomas, 6 low-grade gliomas, 1 embryonal tumor with multilayered rosettes, 1 pineoblastoma, 1 uveal ganglioneuroma, 1 choroid plexus carcinoma, 1 chordoma, and 1 high-grade neuroepithelial tumor. In 25 cases (81%), results impacted patient management by: (i) clarifying diagnosis, (ii) identifying pathogenic germline mutations, or (iii) detecting potentially targetable alterations. The pathologic diagnosis was amended after genomic profiling for 6 patients (19%), including a high-grade glioma to pilocytic astrocytoma, medulloblastoma to pineoblastoma, ependymoma to high-grade glioma, and medulloblastoma to CNS high-grade neuroepithelial tumor with BCOR alteration. Multiple patients had pathogenic germline mutations, many of which were previously unsuspected. Potentially targetable alterations were identified in 19 patients (61%). Additionally, novel likely pathogenic alterations were identified in 3 cases: an in-frame RAF1 fusion in a BRAF wild-type pleomorphic xanthoastrocytoma, an inactivating ASXL1 mutation in a histone H3 wild-type diffuse pontine glioma, and an in-frame deletion within exon 2 of MAP2K1 in a low-grade astrocytic neoplasm. Conclusions Our experience demonstrates the significant impact of molecular profiling on diagnosis and treatment of pediatric brain tumors and confirms its feasibility for use at the time of diagnosis or recurrence.

A multicenter study directly comparing the diagnostic accuracy of gene expression profiling and immunohistochemistry for primary site identification in metastatic tumors.

Metastatic tumors with an uncertain primary site can be a difficult clinical problem. In tens of thousands of patients every year, no confident diagnosis is ever issued, making standard-of-care treatment impossible. Gene expression profiling (GEP) tests currently available to analyze these difficult-to-diagnose tumors have never been directly compared with the diagnostic standard of care, immunochemistry (IHC). This prospectively conducted, blinded, multicenter study compares the diagnostic accuracy of GEP with IHC in identifying the primary site of 157 formalin-fixed paraffin-embedded specimens from metastatic tumors with known primaries, representing the 15 tissues on the GEP test panel. Four pathologists rendered diagnoses by selecting from 84 stains in 2 rounds. GEP was performed using the Pathwork Tissue of Origin Test. Overall, GEP accurately identified 89% of specimens, compared with 83% accuracy using IHC (P=0.013). In the subset of 33 poorly differentiated and undifferentiated carcinomas, GEP accuracy exceeded that of IHC (91% to 71%, P=0.023). In specimens for which pathologists rendered their final diagnosis with a single round of stains, both IHC and GEP exceeded 90% accuracy. However, when the diagnosis required a second round, IHC significantly underperformed GEP (67% to 83%, P<0.001). GEP has been validated as accurate in diagnosing the primary site in metastatic tumors. The Pathwork Tissue of Origin Test used in this study was significantly more accurate than IHC when used to identify the primary site, with the most pronounced superiority observed in specimens that required a second round of stains and in poorly differentiated and undifferentiated metastatic carcinomas.