Neuroendocrine neoplasms of the head and neck: some suggestions for the new WHO classification of head and neck tumors

As knowledge and understanding in pathology evolve, classifications and nomenclature also change to reflect those advances. The 2005 World Health Organization Classification of Head and Neck Tumours was a significant step towards diagnostic standardization of head and neck neuroendocrine carcinomas; however, in the last 10 years there have been new data supporting the recognition of "large cell neuroendocrine carcinoma" as a distinctive high grade carcinoma in the head and neck, a lesion not included in the 2005 Classification. In addition, the terms "middle ear adenoma" and "carcinoid tumor of middle ear" are still widely used to describe a neoplasm that is neither a pure adenoma nor a carcinoid tumor but a lesion with variable mixed exocrine and endocrine differentiation. Largely using the diagnostic criteria of the WHO classification of neuroendocrine carcinomas of the lung, we propose the terms "neuroendocrine carcinoma, grade 1"; "neuroendocrine carcinoma, grade 2"; "neuroendocrine carcinoma, grade 3, large cell type"; and "neuroendocrine carcinoma, grade 3, small cell type" for the classification of neuroendocrine carcinomas of the head and neck in a future WHO classification. In addition, we also proposed the term "mixed epithelial neuroendocrine tumor" of the middle ear as an alternative for "middle ear adenoma" and "carcinoid tumor of the middle ear".

Discovery of prognostic and predictive tissue biomarkers in patients with resectable esophageal cancer

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Background: Patients with operable esophageal adenocarcinoma have a poor prognosis (median survival <2 years). We aimed to discover novel prognostic and predictive biomarkers to be validated as tools for patient selection for optimal neo-adjuvant therapy. Methods: Protein levels of XPF, MUS81, Cyclins A, B1, D1 and E, and Ki67 were assessed by retrospective immunohistochemical analysis of baseline tumor biopsy samples from 3 groups of patients with operable esophageal adenocarcinoma: surgery alone (N=54), 2 cycles of cisplatin-fluorouracil chemotherapy followed by surgery (N=46), and 2 cycles of oxaliplatin-fluorouracil chemotherapy (N=38). Expression of 48,803 genes was studied by Illumina HT-12 chip array followed by functional pathway analysis in oxaliplatin-treated patients before and after chemotherapy (N=38). Results were tested for association with pathological response (Mandard regression grading) (Chi-square test), disease free survival (DFS) and overall survival (OS) (Wilcoxon test). Results: High Ki67 protein levels were associated with worse OS (P=0.034; N=93). None of the markers were predictive of clinical endpoints following cisplatin chemotherapy. In oxaliplatin-treated patients (N=38), functional pathway analysis revealed associations between overexpression of cell cycle/DNA repair genes at baseline and worse clinical outcomes. Expression of 15 DNA repair (DNAR) genes was associated with DFS, and 16 DNAR genes with OS. Expression of 21 DNAR genes significantly increased after chemotherapy. Gene expression associations were validated at the protein level: high MUS81 at baseline predicted poor DFS (P=0.036) and poor OS (P=0.015) following oxaliplatin therapy; high XPF expression was associated with lack of pathological response (P=0.032); high Cyclin B1 predicted poor DFS (P=0.017). XPF protein levels increased following oxaliplatin (P=0.001, paired t-test). Conclusions: By confirmation of mRNA findings at the protein level, XPF, MUS81, and Cyclin B1 have been discovered as predictive biomarkers for response to oxaliplatin chemotherapy that merit prospective validation as tools for patient selection. Funded by Oxford NIHR Biomedical Research Centre and ECMC.

A pathologist's survey on the reporting of sessile serrated adenomas/polyps

AIM

The purpose of this survey was to ascertain reporting habits of pathologists towards sessile serrated adenomas/polyps (SSA/P).

METHODS

A questionnaire designed to highlight diagnostic criteria, approach and clinical implications of SSA/P was circulated electronically to 45 pathologists in the UK and North America.

RESULTS

Forty-three of 45 pathologists agreed to participate. The vast majority (88%) had a special interest in gastrointestinal (GI) pathology, had great exposure to GI polyps in general with 40% diagnosing SSA/P at least once a week if not more, abnormal architecture was thought by all participants to be histologically diagnostic, and 11% would make the diagnosis if a single diagnostic histological feature was present in one crypt only, while a further 19% would diagnose SSA/P in one crypt if more than one diagnostic feature was present. The vast majority agreed that deeper sections were useful and 88% did not feel proliferation markers were useful. More than one-third did not know whether, or did not feel that, their clinicians were aware of the implications of SSA/P.

CONCLUSIONS

98% of pathologists surveyed are aware that SSA/P is a precursor lesion to colorectal cancer, the majority agree on diagnostic criteria, and a significant number feel that there needs to be greater communication and awareness among pathologists and gastroenterologists about SSA/P.

Proximal colon cancer and serrated adenomas - hunting the missing 10%

There is a 10% shortfall in the number of proximal colorectal cancer cases detected by the UK Bowel Cancer Screening Programme and the actual number of UK-registered proximal colorectal cancers. Sessile serrated adenomas/polyps (SSA/P) are common premalignant lesions in the proximal colon and are notoriously difficult to spot endoscopically. Missed or dismissed SSA/Ps might contribute to this UK proximal colon cancer detection disparity. In Oxfordshire, a service evaluation audit and histological review has shown a linear increase in the detection rate of these lesions over the past 4 years. This is the result of increased endoscopist and pathologist awareness of these lesions and improved interdisciplinary communication. This is the result of increased endoscopist and pathologist awareness of these lesions, together with improved interdisciplinary communication, and we predict that this will lead to a comparable detection increase nationwide. Ongoing surveillance of an increasing number of these premalignant lesions could become a significant endoscopic resource requirement once UK guidelines on serrated lesion follow up are established.

Molecular characteristics of a pancreatic adenocarcinoma associated with Shwachman-Diamond syndrome

BACKGROUND

Shwachman-Diamond syndrome (SDS) is characterized by hypoplasia of the bone marrow and exocrine pancreas and a high risk of leukemia. It is unknown whether solid tumors are part of the disease phenotype.

PROCEDURE

We performed copy number alterations using Affymetrix human SNP 6.0 array. Furthermore, we did direct sequencing of pancreatic cancer-related genes and immunohistochemical expression of selective proteins.

RESULTS

Among 41 patients with SDS who enrolled on the registry, we identified one male patient with a solid tumor: moderately differentiated pancreatic ductal adenocarcinoma. The tumor harbored 41 copy number alterations (CNAs) and had no regions of loss of heterozygosity (LOH). None of these CNAs were exclusive to the tumor. One copy of the tumor suppressor genes CTNNA3 and LGALS9C was lost in both the peripheral blood and tumor. Direct sequencing of TP53, KRAS, and NRAS revealed no mutations. Immunohistochemical staining for cyclin D1, E-cadherin, p53 MLH1 and MSH2 and β-catenin, was similar to that seen in non-hereditary pancreatic cancer.

CONCLUSIONS

Our case raises the possibility that solid tumors are associated with SDS, thereby broadening the clinical phenotype of the disease. The relatively young age at cancer diagnosis and the specific involvement of the pancreas make the possibility of an association with SDS likely. Similar to leukemia in SDS, the pancreatic cancer developed in hypoplastic tissues. This observation and the relative genomic stability of the tumor strengthen the hypothesis of improved adaptation of malignant clones among a population of disadvantaged cells as a mechanism for tumor expansion in SDS.

Gene of the month: KRAS

This is a general overview of KRAS, its structure and role in pertinent cancers. Also its role in determining adjuvant therapy is discussed.

Intraduct papillary mucinous neoplasm of the pancreas: a tumour linked with IgG4-related disease?

Objectives

Intraduct papillary mucinous neoplasm (IPMN) is a pancreatic tumour that is often associated with chronic pancreatitis (CP) in the surrounding pancreas. Type 1 autoimmune pancreatitis (AIP) is a fibro-inflammatory condition with characteristic histological features and prominent IgG4+ plasma cells and is part of the spectrum of IgG4-related disease (IgG4-RD). The aim of this study was to determine whether CP associated with pancreatic IPMN commonly represents AIP.

Methods

We identified two consecutive ‘index’ cases of pancreatic IPMN during routine reporting in which the adjacent pancreas showed morphological features suggestive of AIP. These cases were investigated using the Boston criteria for the histopathological diagnosis of IgG4-RD and the HISORt criteria for the clinical and histopathological diagnosis of AIP. Using the same criteria, we proceeded to a clinical review of 12 extra cases of IPMN in which the tumour or the surrounding pancreas showed significant lymphoplasmacytic inflammation and/or fibrosis.

Results

Both of the ‘index’ cases fulfilled the HISORt criteria for AIP and both had morphological features characteristic of IgG4-RD using the Boston criteria, although only one possessed features ‘highly suggestive of IgG4-RD’ after immunohistochemistry. Additionally, both ‘index’ cases had radiological features that could represent extrapancreatic manifestations. Review of the 12 additional cases of IPMN revealed no further examples showing co-existent AIP.

Conclusion

While pancreatic IPMN and AIP may co-exist, most CP associated with IPMN does not represent AIP.

Reporting trends of right-sided hyperplastic and sessile serrated polyps in a large teaching hospital over a 4-year period (2009-2012)

AIM

An audit of serrated polyps diagnosed over a 4-year period: 2009 to 2012 was undertaken to ascertain the reporting trends of sessile serrated polyps (SSP).

METHODS

All right sided hyperplastic polyps (HP) proximal to the splenic flexure and all polyps designated SSP were retrieved from the study period. Three pathologists blinded to the original diagnosis re-examined the slides. Recent American College of Gastroenterology guidelines for the diagnosis of SSP was utilised.

RESULTS

No cases of SSP were diagnosed in 2009. In 2010, 32 right-sided cases were encountered, 83 confirmed in 2011 and 134 confirmed in 2012. The vast majority of these were right-sided. With regards to right-sided HP that were re-classified as SSP the data is as follows: 20 of 66 in 2009 (30%); 58 of 91 in 2010 (64%); 42 of 106 (40%) in 2011 and 69 of 206 in 2012 (33%).

CONCLUSIONS

This study has demonstrated an almost exponential increase in the diagnosis of SSP over a 4-year period. In addition, 30 to 64% of right-sided HP were re-classified as SSP over the 4-year period suggesting that greater awareness of the diagnostic criteria for SSP is required. SSP is an important precursor lesion in the serrated pathway of colorectal cancer. Its recognition is important for surveillance and therapeutic strategies.

Lipid-rich ("clear cell") neuroendocrine tumors of the pancreas in MEN I patients

The presence of "clear" or lipid-rich cells within pancreatic neuroendocrine tumors is thought to be pathognomonic of von Hippel-Lindau (VHL) disease, especially in the context of multiple tumors. However, we encountered the presence of lipid-rich cells in six of 16 patients (eight microadenomas/adenomas) who had multiple endocrine neoplasia type I (MEN I). Three of the lesions (two microadenomas and one adenoma) were composed entirely of lipid-rich cells while the remaining five lesions had a component of lipid-rich cells. All lesions containing lipid-rich cells were negative for α-inhibin, but positive for chromogranin and synaptophysin. In addition, four of the eight lesions were glucagon positive. None of the patients had clinical symptoms related to hormone production. We suggest that lipid-rich cells are not reflexly indicative of VHL, and that they may be encountered in a proportion of cases of MEN I either focally or constituting the entire neuroendocrine lesion.

Gastrointestinal cancers accompanied by a dense lymphoid component: an overview with special reference to gastric and colonic medullary and lymphoepithelioma-like carcinomas

This review highlights the difference between so-called medullary carcinoma and lymphoepithelioma-like carcinoma with reference to the gastrointestinal tract. The two terms have been applied synonymously in the gastrointestinal tract, with the majority of carcinomas associated with lymphocytes being termed medullary carcinomas. True medullary carcinomas are disposed in syncytial sheets and have well defined peripheral margins; the preponderance of inflammation is peri-tumoural. These tumours are also associated with microsatellite instability (MSI). Lymphoepithelioma-like carcinomas tend not to have continuous sheets of tumour but are instead made up of small clusters and aggregates of tumour that are broken up by large numbers of intra-tumoural lymphocytes. These tumours may be associated with Epstein-Barr virus (EBV). Occasional cases may be associated with epigenetic silencing of MLH-1. In conclusion, carcinomas associated with dense lymphoid stroma maybe associated with either MSI or EBV. There are some morphological features that favour either type and in the stomach MSI and EBV are mutually exclusive.

Use of DNA repair proteins translated from biomarker screening to predict overall survival in patients with esophageal cancer treated with oxaliplatin chemotherapy

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Background: Oxaliplatin is first-line chemotherapy for colorectal, gastric, and esophageal cancers. Aim was to identify key determinants of oxaliplatin sensitivity and optimise these biomarkers to select patients for chemotherapy. Methods: High-throughput screening of oxaliplatin sensitivity was performed in a Schizosaccharomyces pombe deletion library of 229 DNA repair strains and Chinese Hamster Ovary (CHO) cell lines with mutations in specific proteins. Biopsies were taken from 50 patients with esophageal cancer, who then received two cycles of oxaliplatin and fluorouracil chemotherapy prior to surgery. Levels of DNA repair proteins were quantified by immunohistochemistry and by qRT-PCR. Results: Twelve lead biomarkers were identified from the preclinical models. In CHO cells, XPF and ERCC1 mutants were approximately 30 times more sensitive than the WT cells (p<0.01). In comparison to WT CHO cells, XPF-deficient cells had prolonged delay in mid-late S-phase after oxaliplatin treatment, and persistence of double strand breaks for at least 48 hours. Modified Comet assay confirmed persistence of inter-strand crosslinks created by oxaliplatin. Cells deficient in DNA polymerase eta (pol eta) also accumulated in S-phase and were 3-fold more sensitive (p<0.01) to oxaliplatin treatment than pol eta-complemented cells. Knockdown of XPF, ERCC1 or pol eta sensitised both oxaliplatin-resistant and oxaliplatin-sensitive HCT116 cells to oxaliplatin. In patients with esophageal cancer, low or absent XPF protein expression predicted complete pathological response to chemotherapy with a sensitivity of 58% and specificity of 72%. Cyclin A protein levels (univariate analysis, p<0.005) and pol eta mRNA levels (multivariate analysis, P<0.005) in pre-treatment esophageal biopsies correlated with overall survival. Conclusions: Results suggest that inter-strand DNA cross-links are the principal cytotoxic lesions created by oxaliplatin. Homologous recombination and damage checkpoint proteins are leading biomarkers for patient selection. In patients with esophageal cancer, XPF and pol eta predict response to oxaliplatin chemotherapy.

Primary nodal hemangioma

Benign vascular tumors arising primarily in lymph nodes are rare. The importance of identifying these entities is to avoid misdiagnosing them as malignant vascular tumors, which occur more often in lymph nodes. Hemangioma is a benign nodal vascular tumor, but its occurrence in lymph nodes is extremely rare. Hemangiomas can occur at any age, mostly in females. It is usually asymptomatic, affects only one node, and does not recur. Four histologic types of hemangioma have been identified: capillary/cavernous, lobular capillary, cellular, and epithelioid. This review highlights the key features of previously reported cases and discusses the differential diagnosis.