Hyper Mucinous Proliferations in the Mucosa of Patients with Inflammatory Bowel Disease: Histological Lesions with a Real Potential for Neoplastic Evolution?

BACKGROUND AND AIMS: Mucin disfunction is a critical event in the pathogenesis of inflammatory bowel disease (IBD). Although hyper mucinous conditions have a still debated implication in the clinical evolution of this disorder, hyper mucinous villous proliferations were found to have a preneoplastic biologic potential. We studied morphologic and immunophenotypic characteristics of these lesions in ileocolonic resections for IBD to add evidence about the evolutive potential of these lesions in samples with well oriented wall structures. METHODS: Morphologic characteristics of bowel samples from 20 patients resected for IBD and with raised lesions at gross examination were studied and sections from cases with hyper mucinous lesions were stained with the following antibodies: Ki 67, p21, and p27, which were employed to evaluate the characteristics of the proliferative and differentiative activity of the epithelial structures; mismatch repair proteins and p53 have been studied as proteins implicated in carcinogenesis in IBD-affected mucosa; mucins subtypes in hyper mucinous structures were evaluated with MUC-2 and MUC-6. The results in 11 cases of saplings were that they harbored hyper mucinous proliferations. The occurrence of hyper mucinous structures was not related to dysplastic lesions, pseudo pyloric metaplasia, subtype of disease, or activity. In only one of our cases, mild cytologic atypia in the proliferative compartment was detected. Proliferation markers (Ki 67, p53) were expressed in the proliferative compartments of mucosal crypts and antiproliferative proteins p21 and p27 were expressed in differentiated epithelium. MMR proteins expression was limited to the proliferative compartment of the hyper mucinous projections. Mucin subtypes distribution was regular in the epithelium of hyper mucinous proliferations. CONCLUSIONS: The present monocentric retrospective study was conducted on surgical samplings with well oriented crypts. Collected data show that hyper mucinous features are frequent occurrences in raised lesions in IBD patients. In hyper mucinous proliferations of the selected cases, the status of the proliferative cycle, the expression of the proteins most frequently involved in carcinogenetic pathways of mucosa affected by IBD, and the mucins subtypes expression have no evident anomalies. Findings are not consistent with the increased risk of neoplastic evolution observed in other studies; rather, they suggest a hyperplastic nature. However, the capacity of hyper mucinous raised lesions for neoplastic evolution should be ruled out with more extensive prospective studies to identify functional defects that could explain the hypothesized neoplastic potential.

The Histology-Driven Differential Diagnosis in Bowel Inflammatory Conditions Is Not All That Obvious: Evidence from a Survey Based on Digital Slides.

(1) Background: when the pathologist faces histologic slides from colonoscopies in daily practice, given the large number of entities and etiologies under inflammatory bowel conditions, in-depth definition of the histological spectrum and the recommendations of current guidelines are often not enough to conclusively define a diagnostic framework. Histological patterns should be organized hierarchically in flowcharts that consider the correlation with clinical data. We conducted an online survey asking a group of gastroenteropathologists to apply a pattern classification based on the most significant lesions in colitis differential diagnosis: crypt distortion and activity. (2) Methods: digital slides from 20 endoscopy samples were analyzed by twenty pathologists and classified according to the occurrence of crypt distortion (nondestructive-destructive colitis) and subsequently to the evidence of activity (ND1-2-3, D1-2). (3) Results: in 8 out of 20 (40%) cases, the participants reached a full agreement regarding the evaluation of crypt distortion (5 cases: nondestructive colitis; 3 cases: destructive colitis). The calculated agreement was k = 0.432. In the second-level quiz (ND1-2-3 and D1-2), full agreement between participants was achieved for 7 of the 28 (25%) possible classifications, with k = 0.229. (4) Conclusions: The findings from this survey are indicative of an unexpectedly low consensus, even among dedicated pathologists, about the recognition of histological changes that are commonly considered critical lesions in the histologic identification of bowel non-neoplastic diseases. In our opinion, these divergences imply a significant risk of misdiagnosis of bowel inflammatory conditions, hampering the usefulness of histological assessment.

Predictive Factors of Surgical Recurrence in Patients with Crohn's Disease on Long-Term Follow-Up: A Focus on Histology.

In patients with Crohn's disease (CD) that underwent surgery, predictive factors of surgical recurrence have been only partially identified. The aim of our study was to identify potential factors associated with an increased risk of surgical recurrence. A monocentric retrospective observational study was conducted including patients diagnosed with CD, according to ECCO criteria who received their first ileocolic resection. Overall, 162 patients were enrolled in our study; 54 of them were excluded due to a lack of sufficient data. The median follow-up was 136.5 months, IQR 91.5−176.5, and the surgical recurrence rate after the median follow-up was 21.3%. In the multivariate analysis, an age ≤ 28 years at the first surgical resection (aHR = 16.44, p < 0.001), current smoking (aHR = 15.84, p < 0.001), female sex (aHR = 7.58, p < 0.001), presence of granulomas at local lymph nodes (aHR = 12.19, p < 0.001), and treatment with systemic corticosteroids after the first surgical resection (aHR = 7.52, p = 0.002) were factors significantly associated with a risk of surgical recurrence, while cryptitis resulted in a protective factor (aHR = 0.02, p < 0.001). In conclusion, the heterogeneous spectrum of factors associated to the risk of surgical recurrence in patients with CD that underwent ileocolic resection supports the need of a personalized follow-up taking into account different clinical, surgical, and histologic features.

Case Report: Morphologic and Functional Characteristics of Intestinal Mucosa in a Child With Short Bowel Syndrome After Treatment With Teduglutide: Evidence in Favor of GLP-2 Analog Safety.

Teduglutide is a glucagon-like peptide-2 (GLP-2) analog employed in patients with short bowel syndrome (SBS) to reduce the need of parenteral nutrition in these patients, by virtue of its effects on enteric function. The experimental studies reported that the stimulating action of GLP-2 on epithelial turnover implies the potential development of dysplastic and neoplastic lesion. However, the clinical trials could not detect preneoplastic lesions on histologic material, and in a recent pilot study the occurrence of polyps was similar before and after treatment and included only low-grade dysplastic lesions. Another clue in GLP-2 function in stimulating mucosal restore is its enhancement through cooperation with epidermal growth factor (EGF). In this study, we analyzed gastroscopy and colonoscopy samplings from a child successfully weaned off parenteral nutrition with teduglutide. Villous and crypt structure was regular both in duodenal and in colonic samplings; in properly oriented villi, villus/crypt ratio was regular. The absorptive epithelium demonstrated a regular morphology. No atypia was detected in enterocytes, along epithelial structures. At the ultrastructural analysis, only a few enterocytes with vacuolized cytoplasm were observed. An S-phase marker Ki67 stained nuclei in the transitional amplifying zone, while nuclei stained by the cell cycle regulatory proteins p21 and p27 were placed in the differentiated epithelium of the duodenal villi and colonic crypts, as in the control cases. The counts of enterocytes immunostained with the same antisera, evaluated with image analysis software, were in the range of control cases. The ratio of the number of epidermal growth factor receptor (EGFR) signals/the number of centromere probe of chromosome 7 (CEP7) signals was less than 2. The findings available from this single patient are consistent with good preservation of functional capability of intestinal epithelium after treatment with GLP-2, given the histologic and ultrastructural features of enterocytes. In addition, the findings from cell cycle regulatory proteins immunolocalization and quantitative analysis show that cell renewal machinery in our case is comparable to control cases. The gene of the receptor EGFR is regularly expressed in enteric epithelium of our case. Morphologic and functional data from our patient improve evidence in favor of the safety of GLP-2 employ in SBS.

Histopathology of inflammatory bowel disease - Position statement of the Pathologists of the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) and Italian Group of Gastrointestinal Pathologists (GIPAD-SIAPEC).

Diagnosis of the inflammatory bowel diseases ulcerative colitis (UC) and Crohn's disease (CD) relies mainly on the histopathological examination of endoscopic biopsies of the gastrointestinal tract. To facilitate the accurate diagnosis of these two conditions, this paper addresses key issues on the: (A) gastrointestinal biopsy procedure, (B) histomorphological characteristics of UC and CD, and (C) diagnosis of dysplasia. The 13 statements presented here represent the consensus of two groups of Italian pathologists (IG-IBD and GIPAD).

Eosinophilia - associated basal plasmacytosis: an early and sensitive histologic feature of inflammatory bowel disease.

Basal plasmacytosis is an early-onset and highly predictive feature of inflammatory bowel disease (IBD), but may have several restrictions in routine histology. Considering evidences about cooperation between eosinophils and plasma cells in IBD pathogenesis, we investigated immunostain of these two cells as a marker of disease. 343 samplings from 83 patients (52 IBD, 31 non-IBD colitis) were evaluated. The sections were stained with monoclonal antibodies against plasma cells (CD138 and MUM1), and eosinophils (CD193). Eosinophilia-associated basal plasmacytosis (EBP) was related with the histologic diagnosis of IBD (90.3% IBD and 35.4% non-IBD colitides, p < 0.005, sensitivity 90.4%). A strong relation was detected between the occurrence of EBP and (i) the achieving of a complete endoscopic mapping; (ii) the presence of other characteristic lesions of IBD in single segmental sampling, although EBP was evident in more than 40% of samples without other IBD-related lesions. EBP is a sensitive histologic feature of IBD, especially at the first endoscopic sampling, even in the absence of the other characteristic histologic lesions, and may help in formulating a more precise diagnosis in this setting.

The diagnosis of inflammatory bowel disease is often unsupported in clinical practice.

BACKGROUND: The diagnosis of inflammatory bowel disease can be challenging and requires the efforts of a multidisciplinary team. We performed a retrospective analysis with the aim of evaluating the adequacy of the prerequisites for arriving at an accurate histological diagnosis. METHODS: The following parameters were considered as prerequisites for a diagnosis of inflammatory bowel disease: clinical and endoscopic data; proper sampling and handling of biopsies; and elementary microscopic lesions. We collected 345 cases from 13 centres. RESULTS: The date of onset and treatment were available for 13% and 16% of the cases, respectively. Endoscopy information was accessible for 77% of the cases. Endoscopic mapping was completed in 13% of the cases. In no cases were the biopsies oriented on acetate strips. The diagnosis was conclusive in 47% of the cases. Activity, epithelial disruption and crypt distortion were described in 35% of the reports with a conclusive diagnosis. CONCLUSION: Our study showed that the diagnostic prerequisites were widely unfulfilled, although approximately half of the diagnoses were conclusive for inflammatory bowel disease. Thus, in our assessment of clinical practice: (1) clinicians seldom provide suitable clinical and/or endoscopic information for a histological diagnosis and (2) histopathological diagnoses of inflammatory bowel disease are often not supported by morphology.

Inflammatory bowel disease: a proposal to facilitate the achievement of an unequivocal diagnosis.

Following the international guidelines criteria an adequate "diagnostic conclusion" of inflammatory bowel disease (IBD) can be achieved only if clinical, endoscopic and laboratory findings, together with sample technical adequacy and unequivocal histomorphological signs of the disease are available. Thus, a conclusive diagnosis requires a complex combination of clinical, endoscopic and histological data. A considerable number of endoscopic biopsies obtained from IBD patients do not meet the above-mentioned requirements. The aim of the present proposal is to introduce a binary system of evaluation in the "diagnostic conclusion" of the histopathological report that will help to simplify the clinical decisions and consequent patient management. In patients with no history of disease, the pathologist should classify the biopsies in "Diagnostic", when the criteria established by the international guidelines are satisfied and "not diagnostic" when one or more of the above-mentioned criteria are not met. The term "not diagnostic" should replace "highly suggestive" and "probable". This new terminology could avoid ambiguous expressions that encourage the clinician to classify the patient as affected by IBD without fulfilling all of the requirements for an accurate diagnostic approach.

Expression of the E-cadherin-catenins complex in sentinel node is related to tumor morphology but not to spread to nonsentinel nodes.

The sentinel node (SN) technique has gained a key role in breast cancer surgery, allowing for an accurate staging of the axillary status with a minimally invasive resection. In this study, we explored the implication of three proteins (E-cadherin, a- and b-catenins) that form the cadherin-catenin complex, a receptorial structure strictly involved in tumoral vascular invasion and embolization in this biologic event. We studied the immunohistochemical expression of the complex in patients with metastatic SN, matching the group with involved nonsentinel lymph nodes (NSNs) with that having free axillary NSNs. The simultaneous staining of the SN metastases for the three proteins has been considered an indicator of preserved function. Our data confirmed the lack of cadherin-catenin complex in tumors with lobular morphology even in SN metastasis, but statistical evaluation could not prove a significant relation between complex integrity and NSN involvement. Moreover, considering traditional histopathologic parameters, only vascular peritumoral embolization was related to an increased risk of metastatic spread to axillary NSNs.