MLH1, BRAF and p53 - searching for significant markers to predict evolution towards adenocarcinoma in colonic sessile serrated lesions.

BACKGROUND AND AIM: Colonic serrated lesions are premalignant lesions, using an alternative malignization pathway, including multiple genetic and epigenetic alterations, as: mismatch repair deficiency due to MutL homolog 1 (MLH1) promoter methylation, tumor protein p53 (TP53) mutations, activating mutations of v-Raf murine sarcoma viral oncogene homolog B (BRAF) and Kirsten rat sarcoma viral oncogene homolog (KRAS). Our study aims to evaluate MLH1, BRAF and p53 immunohistochemical (IHC) status in sessile serrated lesions (SSLs), with and without dysplasia. MATERIALS AND METHODS: This is a retrospective case-control study including 20 SSLs with dysplasia and 20 SSLs without dysplasia (matching sex and age). IHC expression of MLH1, BRAF and p53 was evaluated as the percent of nuclear loss of MLH1, cytoplasmic positivity of BRAF and nuclear positivity of p53. Data concerning age, sex, localization of the lesion, dysplasia and IHC results were statistically processed using Microsoft Excel. RESULTS: We had very polymorphous patterns of IHC expression for BRAF, MLH1 and p53, especially in the dysplastic group. Thus, two patients were BRAF+∕MLH1-∕p53+, three were BRAF+∕MLH1-∕p53-, one was BRAF+∕MLH1+∕p53- and six were BRAF+∕MLH1+∕p53+. Dysplastic lesions without BRAF mutation exhibited the following phenotype: one case BRAF-∕MLH1-∕p53+, four BRAF-∕MLH1-∕p53- and three BRAF-∕MLH1+∕p53+. In the control group (SSLs without dysplasia), there was a more homogenous distribution of cases: eight cases BRAF+∕MLH1+∕p53-, seven BRAF-∕MLH1+∕p53-, one BRAF-∕MLH1-∕p53+, two BRAF-∕MLH1-∕p53- and two BRAF-∕MLH1+∕p53+. CONCLUSIONS: There are more routes on the serrated pathway, with different mutations and time of acquisition of each genetic or epigenetic lesion with the same morphological result. These lesions should be stratified according to their risk to poor outcome and their need to further surveillance.

Dangerous Liaison: Helicobacter pylori, Ganglionitis, and Myenteric Gastric Neurons: A Histopathological Study.

Chronic inflammation induced by Helicobacter pylori (H. pylori) infection plays a major role in development of gastric cancer. However, recent findings suggested that progression of inflammation and neoplastic transformation in H. pylori infection are more complex than previously believed and could involve different factors that modulate gastric microenvironment and influence host-pathogen interaction. Among these factors, gastric myenteric plexus and its potential adaptive changes in H. pylori infection received little attention. This study is aimed at identifying the impact of H. pylori-associated gastritis on number and morphology of nerve cells in the stomach. The distribution of density, inflammation, and programmed cell death in neurons was immunohistochemically assessed in full-thickness archival tissue samples obtained from 40 patients with H. pylori infection who underwent surgery for gastric cancer and were compared with findings on samples collected from 40 age- and sex-matched subjects without bacteria. Overall, significant differences were noted between H. pylori-positive and H. pylori-negative patients. The analysis of tissue specimens obtained from those with infection revealed higher density and larger surface of the myenteric nervous plexus, as well as a significant increase in the number of gastric neuronal cell bodies and glial cells compared to controls. A predominant CD3-immunoreactive T cell infiltrate confined to the myenteric plexus was observed in infected subjects. The presence of mature B lymphocytes, plasma cells, and eosinophils was also noted, but to a lesser extent, within the ganglia. Myenteric ganglionitis was associated with degeneration and neuronal loss. Our results represent the first histopathological evidence supporting the hypothesis that H. pylori-induced gastric inflammation may induce morphological changes in myenteric gastric ganglia. These findings could help gain understanding of some still unclear aspects of pathogenesis of H. pylori infection, with the possibility of having broader implications for gastric cancer progression.

Expression Profile of p53 and p21 in Large Bowel Mucosa as Biomarkers of Inflammatory-Related Carcinogenesis in Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic, relapsing inflammatory bowel disease that slightly increases the risk of colorectal cancer in patients with long-standing extended disease. Overexpression of p53 and p21 in colonic epithelia is usually detected in UC patients when no dysplasia is histologically seen and it is used by pathologists as a discriminator between regenerative changes and intraepithelial neoplasia, as well as a tissue biomarker useful to predict the risk of evolution toward malignancy. We present a one-year prospective observational study including a cohort of 45 patients with UC; p53 and p21 were evaluated in epithelial cells. p53 was positive in 74 samples revealed in 5% to 90% of epithelial cells, while 63 biopsies had strong positivity for p21 in 5% to 50% of epithelial cells. Architectural distortion was significantly correlated with p53 overexpression in epithelial cells. Thus, we consider that architectural distortion is a good substitute for p53 and p21 expression. We recommend use of p53 as the most valuable tissue biomarker in surveillance of UC patients, identifying the patients with higher risk for dysplasia. Association of p21 is also recommended for a better quantification of risk and for diminishing the false-negative results.

Correlations Between the Density of Tryptase Positive Mast Cells (DMCT) and that of New Blood Vessels (CD105+) in Patients with Gastric Cancer.

Mast cells proteases, tryptase and chymase are directly involved in the growth and progression of solid tumors due to their important role in tumor angiogenesis. We examined the density of tryptase positive mast cells and the mean density of new blood vessels in gastric malignant tumors of patients with and without Helicobacter pylori infection, using immunohistochemical staining for tryptase (for mast cells) and CD 105 (for new vessels). Tryptase and CD 105 expression was detected in gastrectomy specimens. In this study, mast cell density correlates with angiogenesis and the growth and progression of gastric cancer. It also shows that the participation of Helicobacter pylori infection in the growth and progress of gastric neoplasia is due to an increase of peritumoral angiogenesis, with subsequent local and distant tumor spread and perivascular growth, but without perineural and nodal involvement.

Density of Tryptase-Positive Mast Cells Correlated with the Presence of H. pylori in Gastric Neoplasia.

BACKGROUND: Gastric cancer continues to be a platoon leader of mortality causes. A significant number of recent studies show direct or indirect involvement of mast cells (MC), with a complex role both pro- and anti-tumor growth. AIM: To objectify the correlations between expression of MC and presence of Helicobacter pylori (HP) infection depending on neoplastic nature of the gastric damage. SUBJECTS AND METHODS: The study was carried out on archival samples of gastric wall from 30 patients with gastric cancer versus 30 age and sex-matched subjects with gastric surgery for non-neoplastic diseases. The inclusion criteria for the case group were histologically proven stage T3/T4 malignancies with regional lymph node metastases. For each case of the study group, distribution and number of MC tryptase positive (DMC-TP) were analyzed in five different areas from the same gastrectomy specimen: intratumor area, deep and side tumor invasion front, normal gastric tissue sample 5-10 cm or more distant from the tumor and furthest resection margin. RESULTS: Independently of HP infection, the study recorded a significantly lower value of DMC-TP in male patients. In regions with inflammatory lesions and preneoplastic changes and in control cases with non-gastric neoplasia, the DMC-TP level was higher than controls with HP-related inflammatory pathology, thus removing bacterial etiology from the forefront of MC mobilizing causes. CONCLUSION: The presence of H. pylori infection was not found to cause significant changes in terms of mobilizing mast cells in the gastric wall with advanced tumors, with minimal stage III TNM.

The Growing Family of Limb-Girdle Muscular Dystrophies: Old and Newly Identified Members.

Limb-girdle muscular dystrophies (LGMD) are an extremely heterogeneous and rapidly expanding group of diseases characterized by progressive weakness of pelvic, scapular and trunk muscles with sparing of facial and distal musculature in most of the subtypes, onset in childhood or in adults of both sexes, very variable clinical severity ranging from mild to severe phenotypes, some associated with cardio-pulmonary and extraskeletal impairment and high serum creatine-kinase (CK) levels. In the past years, huge advances have been recorded in the various identification methods and new distinct entities were discovered. However, it is not yet clear why some muscle groups are affected and others spared in a specific subtype of LGMD, why similar clinical pictures are associated with different genes and mutations, while the same gene or mutation may present with very various clinical phenotypes. In this review we summarize the main aspects of positive and differential diagnosis in LGMD.

Long-standing ulcerative colitis complicated with mantle-cell lymphoma transformed in diffuse large B cell lymphoma.

Ulcerative colitis (UC) is a chronic, relapsing inflammatory disease of the colon and rectum. Its etiology and pathogenesis are incompletely elucidated, although there are many studies concerning these problems. Chronic inflammation and immunosuppressive treatment are risk factors for epithelial and lymphoid malignancies. We present a case of a 39-year-old man who died after a long-standing untreated UC complicated with mantle cell colonic lymphoma and then with transformation towards a high grade diffuse large B cell lymphoma. Multiple colonic biopsies were collected in various moments of the disease. Microscopic and immunohistochemical features are comparatively presented. This case emphasizes the importance of constant surveillance for UC patients and reaffirms the role of multidisciplinary approach in UC management.

Functional and morphological alterations induced by Helicobacter pylori infection in gastric nerve supply.

Helicobacterpylori (HP) infection is the most common cause of many gastric diseases. One of its pathogenic mechanisms involves the production of a wide spectrum of alterations in different components of the gastric enteric nervous system. Changes in neural circuitry encompass structural abnormalities, sensitive and motor function impairment, altered content and release of neurotransmitters, and seem to be related rather to the inflammatory response of gastric wall than to the bacterial colonization. Although gathered data provide new insights into the complex mechanisms underlying the interactions between HP and enteric nervous system, there still are some controversial aspects. Interestingly, it has been suggested that impaired neural activity might have a potential role in gastric carcinogenesis, but this hypothesis requires further investigation. Future studies shall, therefore, elucidate the neuromodulatory influences of Helicobacter pylori infection on the enteric nervous system. A better comprehension on neural changes during HP-induced inflammation could help in identifying new therapeutic options.

Evaluation of histologic features with potential prognostic value in ulcerative colitis.

Inflammatory bowel diseases (IBD) are a complex, heterogeneous, idiopathic, inflammatory, chronic entity with common clinical, endoscopical and histological features including some well-defined diseases (UC and CD), but also a group of indeterminate colitis. Ulcerative colitis is the most frequent and prominent member of IBD. The current study is trying to evaluate the impact of various histologic features on UC's evolution and outcome--an issue that has generated considerable interest in the academical environment. We gathered a cohort of 20 consecutive patients with positive clinical, endoscopical, histologic and imagistic diagnosis of UC who were prospectively enrolled for close clinical, biochemical, endoscopic and histologic surveillance. Every patient underwent an ileo-colonoscopy and multiple biopsies were taken from inflamed and normal areas of the mucosa. All these procedures were repeated after a year (12 months) of follow-up. This study is presenting the correlation between Mayo score for assessment of ulcerative colitis activity and several histologic features: Geboes histologic score for ulcerative colitis, basal plasmacytosis and vascular lesions using Pearson correlation test. The most promising prognosis value has basal plasmacytosis, confirming previous studies. These data emphasize the need of a more complex, clinical, endoscopic and histologic system of semi-quantitative assessment of UC lesions in order to stratify patients according to their risk to relapse.

First Pillcam Colon 2 capsule images of Whipple's disease: Case report and review of the literature.

Whipple's disease is a rare chronic systemic infection determined by the Gram-positive bacillus Tropheryma whipplei. The infection usually mainly involves the small bowel, but sometimes other organs are affected as well. Since the current standard clinical and biological tests are nonspecific, diagnosis is very difficult and relies on histopathology. Here we present the case of a 52-year-old man with chronic diarrhea and weight loss whose symptoms had been evolving for 2 years and whose diagnosis came unexpectedly after capsule examination. Diagnosis was confirmed by the histopathologic examination of endoscopic biopsy samples, and treatment with co-trimoxazole resulted in remission of symptoms. We present the first images of Whipple's disease obtained with the Pillcam Colon 2 video capsule system.

The influence of Helicobacter pylori presence on the immunophenotype of inflammatory infiltrate in gastric diseases.

The first medical hypothesis about the possible relationship between chronic inflammatory response and carcinogenesis belongs to Virchow and it was published in 1893. In these days, multiple studies demonstrate the certain involvement of chronic inflammation as trigger of progression towards malignancy. The fact that in 1994, the International Agency for Research on Cancer considered Helicobacter pylori as first class carcinogenic agent, is postulating the existence of the pathogenical chain carcinogenesis, of chronic inflammatory lesions as it was described by Correa, as a first step. Our study including 75 patients who underwent surgical procedures for gastric lesions uses immunohistochemical studies for lymphocytes phenotyping, to identify the nature of inflammatory cells involved, correlating the results with the presence of Helicobacter pylori. We tried to bring new information needed for establish to what extent the chronic inflammation of gastric mucosa is a response to the presence of bacteria and is implicated in tumorigenesis. We used T cells antibodies: CD3, CD4, CD5, CD8, CD57, GranzymeB and B cells antibodies: Cd20 and CD23. Our results revealed the presence of immune cellular response to Helicobacter pylori in gastric mucosa, based on T helper, cytotoxic and NK cells. B cells have a minor role in this response. CD4+ cells seem to be involved in local protection response as well as in carcinogenesis, while CD8+ have a minor or no role in carcinogenesis.

Dendritic cells--immunodeficiency virus (HIV): early interactions.

Since 1973, when Steinman and Cohn highlighted the importance of dendritic cells as mediators of immunity, a large series of subsequent researches have been registered concerning these amazing cells and their implications in different pathologies. Although in small number, they are widely distributed and represent crucial elements in immune responses against pathogens. Data gathered in the last period, mostly based on in vitro studies, helped us understand the early events of HIV-host interactions, the important roles of dendritic cells in this phase, but fails to fully explain the complex mechanisms underlying these interactions, such as the ways developed by HIV to evade the immune system and to facilitate viral dissemination. Improved knowledge of these mechanisms may provide a basis in the attempt to find new therapeutic targets and elaborate immunologic therapies.

Regression of precancerous epithelial alteration in patients with Helicobacter pylori chronic gastritis.

As a Group 1 carcinogen for gastric cancer, Helicobacter pylori (H. pylori) was involved in many studies and researches focused on physiopathology and morphopathologic changes induced by this bacterium. The study included 3069 gastric endoscopies performed between January 2005 and December 2009 in "Colentina" Clinical Hospital. During upper endoscopy biopsies from antro-pyloric and corporeo-fundic region were collected. Histopathologic diagnosis of these biopsies was made using Sydney criteria. The patients were divided in two groups, based on the presence or absence of H. pylori: group A included 1414 H. pylori positive patients and group B included 1653 H. pylori negative patients. We evaluated several histopathological parameters, correlating the degree of inflammation, atrophy, metaplasia, regenerative hyperplasia and dysplasia with the presence of H. pylori infection. Our study identifies an overall tendency towards regression of premalignant lesions of gastric epithelium (regenerative epithelial hyperplasia, atrophy and intestinal metaplasia) after H. pylori eradication, as well an increasing number of patients diagnosed with early gastric cancer, thus consolidating the results of studies who foretell the significant decrease of gastric cancer mortality. These lesions are present years before becoming clinically manifest, and consequently treatable. In respect of carcinogenic mechanisms, some of our results confirm the carcinogenic cascade triggered by the H. pylori infection, as it was proposed by Correa et al. in 1975. However, we obtained data leading to the idea that the "precursor lesions" could appear (and subsequently histopathologically evaluated) independent one to the other, through other steps then Correa's model.

Diagnosis and treatment in Helicobacter pylori infection.

In our days, Helicobacter pylori is considered to be the bacterium responsible for the most frequent and persistent chronic infection worldwide, involving half of the entire world population. Untreated, the infection is lasting for the whole life. In Romania, the number of carrying people is variable between 90-94%, while in western countries, the prevalence of this infection is much lower, under 50-60%, with a high tendency to decrease, due both to the higher socio-economic level and to advanced methods of diagnosis and treatment, with a special focus on prevention. Because a percentage of 10-11% of the infected people develop in time an ulcerous disease, and 5-6% will have premalignant changes on the gastric mucosa and even gastric cancer in 1% of the cases, the goal to detect and treat H. pylori infection is, in our opinion, very much justified by both theoretical and practical reasons. Diagnosis methods for the infection's detection are numerous and diverse, the choice for one or another depending on several factors, among which: accessibility, advantages and disadvantages specific to each method (particularly the method's invasive or non invasive character), the cost, the aim (diagnosis, epidemiological, the treatment's efficiency, etc.). From a clinical point of view the patient's age, antecedents and digestive symptoms, as well as his psychological state and associated treatments are also important. Once the diagnosis of infection is proved, the treatment of the Helicobacter pylori infection supposes the simultaneous administration of antibiotics and proton pump inhibitors. The idea to create a vaccine for Helicobacter pylori is the evident result of the need to avoid the costs imposed by the diagnosis and treatment of the infection, especially in view of the high percentage of failure in eradicating the infection. If we add to these the socio-economic costs brought by the treatment of gastric ulcers and cancers, the idea of using a vaccine with double role, both in preventing, as well as in treating the infection, is even more attractive.

E-cadherin and beta-catenin expression in gastric neoplastic and non-neoplastic lesions--correlations with H. pylori infection.

Gastric cancer is one of the most aggressive malignancies, as incidence and as evolution as well. Although, due to the new findings about etiology, carcinogenesis, precancerous conditions and their detection, as well as the treatment, in the latest decade, there is an improvement in these data, gastric cancer remains a redoubtable enemy because of its incidence, prevalence and mortality. Researches are focusing on early detection of precursor lesions and on establishing their reversibility potential by bringing more clinical and statistical information and by setting new clinical hypotheses. In this context, the present article is trying to study immunohistochemical expression of two oncogenic markers, the cell adhesion protein antibodies E-cadherin and beta-catenin. Cell to cell and cell to extracellular matrix interactions are crucial for neoplastic transformation and for metastasizing process. The importance of these antibodies in maintaining cell adhesion suggests that their abnormal expression is playing an important role in tumorigenesis. In this article, authors are presenting a study about E-cadherin and beta-catenin expression in 75 patients who underwent gastrectomy for suspicions of gastric malignancies. The variables of the study are the presence or absence of Helicobacter pylori, type I carcinogenetic agent for gastric carcinoma (especially intestinal type adenocarcinoma) and the presence of tumoral or non-tumoral gastric lesions.

Carcinogenesis and infection with Helicobacter pylori.

It was accepted several years ago that, in the carcinogenesis process of human cancers, biologic agents, especially the viruses, are playing an etiologic role. This is the case of lymphomas (retroviruses), hepatocarcinoma (hepatic viruses) and cervical carcinoma (papilloma viruses). Helicobacter pylori is the first bacteria recognized as a first class carcinogen for gastric cancer. Nevertheless, comparing with the most validated human carcinogens, the activity of H. pylori is very little studied. As a consequence, at this moment, in its case, explanation of carcinogenesis mechanism is more or less hypothetical.

Rectal leiomyoma--report of two cases originating in muscularis mucosae.

We present two rare cases of rectal leiomyoma originating in muscularis mucosae. The lesions were incidentally discovered in a 58-years-old woman and 53-years-old man during colonoscopy performed for unrelated symptoms. Both presented as small polyps and were removed by conventional colonoscopic snare polypectomy without clinical recurrence. Gross examination revealed pedunculated polyps covered by non-ulcerated mucosa. Histologically the lesions represent smooth muscle cells proliferation originating in muscularis mucosae. Both lesions were uniformly positive for SMA and DESM and negative for CD34, CD117 and S100. These tumors have a different clinical course than gastrointestinal stromal tumors; since morphologic appearance is sometimes confusing, CD117 staining is mandatory for an accurate diagnostic. We decided to present these cases because of the rarity of this condition concerning both the location and the origins of tumors. We stress the importance of the proper classification of this rare lesion, considering its outmost importance.

Helicobacter pylori: pathological mechanism involved in gastric colonization.

Since 1982, when Marshall and Warren highlighted the presence of H. pylori at the apical pole of the epithelial gastric cells, the medical literature has registered a cascade of subsequent researches concerning this amazing bacterium, its action on the human body and the body response. The apogee of these studies and conclusions about the pathogenic role of HP was touched with its certain recognition as class one carcinogenic agent (Peura 1997, WHO), becoming the first bacteria with such an action. The data gathered in the last period identify different virulence factors of HP, but fail to fully explain the relatively low incidence of gastric cancer in HP carriers; therefore, it is now considered that the carcinogenic potential related to HP infection in humans is due to the synergic and complementary association of the bacterial genetic equipment with diet and host response.

Malignancy and overdiagnosis of malignancy in Peutz Jeghers polyposis.

Peutz Jeghers (PJ) polyps are rare hamartomatous tumors of the gastrointestinal tract frequently associated with skin and mucosal pigmentation. Despite their benign nature there is a certain increased risk of progression to malignancy in some cases, justifying a sustained follow-up of the patients. We present 3 cases of Peutz Jeghers syndrome (PJS) diagnosed in our hospital on gastrointestinal specimens obtained by endoscopy and opened surgery. We analyzed different degrees of dysplastic changes, epithelial intussusception, association with other types of polypoid lesions and other various aspects possibly related with disease progression. Clinico-pathological correlations were made. Two of these cases were related (mother and daughter); both of them were operated in another hospital for small bowel tumors with a subsequent diagnosis of adenocarcinoma. The daughter (28 years old) was referred to our hospital for endoscopic follow-up; a small polyp of the transverse large bowel was excised by colonoscopy with a histopathologic diagnosis of PJ polyp; a careful histopathologic reevaluation of both specimens of enterectomy (slides and paraffin blocks) revealed an overdiagnosis of cancer due to the epithelial cystic dilatation and pseudoinvasion in both patients. The other case showed diagnostic changes of PJS and also various aspects of adenomatous polyps some of them with mild and moderate dysplastic changes. When a PJ polyp is diagnosed, the possibility of pseudoinvasion should be kept in mind, in order to avoid overdiagnosis of malignancy; also, due to the fact that the malignant transformation of a PJ polyp is still on debate (hamartoma-dysplasia-carcinoma sequence versus malignant transformation of an adenomatous aria of a hamartoma versus coincidental association of a digestive cancer due to genetic aberrations of PJS), all the other associated microscopic aspects of the lesion should be carefully analyzed.