Expression of Calretinin in the Cecal Muscularis Interna: Observation and Hypothetical Relevance to Appendicitis.

BACKGROUND: The unexpected observation of calretinin immunoreactivity in smooth muscle cells in the muscularis propria of the cecum led to a more detailed examination of calretinin expression and its possible relationship to propulsive contractile activity around the vermiform appendix. METHODS: Immunohistochemistry and RNA in situ hybridization were performed to analyze calretinin expression in intestinal samples from 33 patients at ages ranging from mid-gestation fetuses to adults, as well as in some potentially relevant animal models. Dual immunolabeling was done to compare calretinin localization with markers of smooth muscle and interstitial cells of Cajal. RESULTS: Calretinin expression was observed consistently in the innermost smooth muscle layers of the muscularis interna in the human cecum, appendiceal base, and proximal ascending colon, but not elsewhere in the intestinal tract. Calretinin-positive smooth muscle cells did not co-express markers located in adjacent interstitial cells of Cajal. Muscular calretinin immunoreactivity was not detected in the ceca of mice or macaques, species which lack appendices, nor in the rabbit cecum or appendix. CONCLUSIONS: Localized expression of calretinin in cecal smooth muscle cells may reduce the likelihood of retrograde, calcium-mediated propulsive contractions from the proximal colon and suppress pro-inflammatory fecal stasis in the appendix.

Occult appendix pathology in patients undergoing colorectal cancer resection and prophylactic appendectomy.

BACKGROUND: The risk-benefit balance of prophylactic appendectomy in patients undergoing left colorectal cancer resection is unclear. The aim of this report is to assess the proportion of histologically abnormal appendices in patients undergoing colorectal cancer resection in a unit where standard of care is appendectomy, with consent, when left-sided resection is performed. METHODS: A retrospective study on a prospectively collected database was conducted in a single tertiary-care center. Overall, 717 consecutive patients undergoing colorectal cancer resection between January 2015 and June 2021 were analyzed. The primary outcome was the proportion of histologically abnormal appendix specimens at prophylactic appendectomy. The secondary outcome was complications from prophylactic appendectomy. RESULTS: Overall, 576/717 (80%) patients had appendectomy at colorectal cancer surgery. In total, 234/576 (41%) had a right-/extended-right hemicolectomy or subtotal colectomy which incorporates appendectomy, and 342/576 (59%) had left-sided resection (left-hemicolectomy, anterior resection or abdominoperineal excision) with prophylactic appendectomy. At definitive histology, 534/576 (92.7%) had a normal appendix. The remaining 42/576 (7.3%) showed abnormal findings, including: 14/576 (2.4%) inflammatory appendix pathology, 2/576 (0.3%) endometriosis, 8/576 (1.4%) hyperplastic polyp, and 18/576 (3.1%) appendix tumors, which encompassed six low-grade appendiceal mucinous neoplasms (LAMNs), three carcinoids, and nine serrated polyps. In the 342 patients who had prophylactic appendectomy, 10 (2.9%) had a neoplasm (two LAMN, three carcinoids, and five serrated polyps). There were no complications attributable to appendectomy. CONCLUSION: Occult appendix pathology in patients undergoing colorectal cancer resection is uncommon when prophylactic appendectomy was performed. However, approximately 3% of patients had a synchronous appendix neoplasm.

Incidence and clinical features of endometriosis in 2484 consecutive female patients undergoing appendectomy for suspected appendicitis-a retrospective analysis.

INTRODUCTION: Endometriosis is a common condition affecting 5 to 10% of women of childbearing age. The true incidence of endometriosis of the appendix is currently unknown. Since symptoms often overlap with those of acute appendicitis, endometriosis of the appendix presents a diagnostic challenge in the emergency department. This large retrospective study investigates the incidence and perioperative clinical, radiologic, and laboratory findings, as well as possible differences between patients with and without endometriosis. METHODS: Data from consecutive patients who underwent appendectomy for suspected appendicitis without a history of endometriosis were analyzed. Perioperative clinical, laboratory, perioperative, and histopathologic findings were compared between women with and without endometriosis. RESULTS: Between January 2008 and June 2023, 2484 consecutive patients without a history of endometriosis underwent urgent appendectomy for suspected appendicitis. Endometriosis was detected on histopathologic examination in 17 (0.7%) patients. Signs of appendicitis were found less frequently on ultrasound in the endometriosis group compared to the non-endometriosis group (23.4% vs. 61.5%; p = 0.002; OR = 0.193; 95% CI 0.063-0.593). There were no differences in physical examination findings, duration of symptoms, degree of inflammation, surgical outcomes, or complication rates. CONCLUSION: The incidence of endometriosis of the appendix in patients undergoing appendectomy for suspected appendicitis was higher than suggested by data from autopsy series and populations with biopsy-proven endometriosis. Patients with endometriosis of the appendix were less likely to have a positive ultrasound finding, but perioperative and histopathologic findings and severity of inflammation did not differ from patients without endometriosis, presenting diagnostic challenges for clinicians.

Compilation of Evidence Supporting the Role of a T Helper 2 Reaction in the Pathogenesis of Acute Appendicitis.

Despite being the most common abdominal surgical emergency, the cause of acute appendicitis (AA) remains unclear, since in recent decades little progress has been made regarding its etiology. Obstruction of the appendicular lumen has been traditionally presented as the initial event of AA; however, this is often the exception rather than the rule, as experimental data suggest that obstruction is not an important causal factor in AA, despite possibly occurring as a consequence of the inflammatory process. Type I hypersensitivity reaction has been extensively studied, involving Th2 lymphocytes, and cytokines such as IL-4, IL-5, IL-9 and IL-13, which have well-defined functions, such as a positive-feedback effect on Th0 for differentiating into Th2 cells, recruitment of eosinophils and the release of eosinophilic proteins and the production of IgE with the activation of mast cells, with the release of proteins from their granules. Cytotoxic activity and tissue damage will be responsible for the clinical manifestation of the allergy. AA histological features are similar to those found in allergic reactions like asthma. The intestine has all the components for an allergic immune response. It has contact with hundreds of antigens daily, most of them harmless, but some can potentially induce an allergic response. In recent years, researchers have been trying to assess if allergy is a component of AA, with their latest advances in the understanding of AA as a Th2 reaction shown by the authors of this article.

Is acute appendicitis complicated or uncomplicated? Approaching the question via computed tomography.

BACKGROUND: The distinction between complicated and uncomplicated appendicitis is very important for the selection of the treatment method. PURPOSE: To investigate the sensitivity and specificity of computed tomography (CT) in differentiating between complicated and uncomplicated appendicitis to demonstrate that false negativity in differentiating these cases can be reduced when CT findings are incorporated into the clinical evaluation of patients. MATERIAL AND METHODS: All patients aged ≥18 years who underwent appendectomy at Malatya Training and Research Hospital in 2020 and 2021 were retrospectively screened. Of them, 283 patients were included in the study who had undergone CT before the operation. Patients with appendicitis were divided into two groups: complicated and uncomplicated, according to the results of their pathology tests. Demographic data, laboratory results, and CT images of the patients were evaluated. RESULTS: The patients with complicated appendicitis had a significantly higher mean age (P<0.001). The most common CT findings in patients with complicated appendicitis were moderate or severe peri-appendiceal fat stranding (PFS) and appendix wall enhancement defect (AWD). The findings with the highest sensitivity were PFS (77.9%) and AWD (69.4%). Although abscess, phlegmon, and peri-appendiceal air had the highest specificity (100%), these findings were the ones with the lowest sensitivity. According to the scoring system was developed for the differential diagnosis, CT had a sensitivity of 83.3% and a specificity of 79.2%. CONCLUSION: Based on the sensitivity and specificity values measured for CT according to the findings of our study, the scoring system may be useful for the differential diagnosis of complicated appendicitis.

Analysis of surgical treatment of appendix neuroendocrine neoplasms-17 years of single-center experience.

BACKGROUND/AIM: This study investigated the clinicopathological characteristics and treatment of appendix neuroendocrine neoplasms in appendectomy specimens of our center. MATERIALS AND METHODS: The clinicopathological data, including age, sex, preoperative clinical manifestation, surgical method, and histopathological examination results of 11 patients with appendix neuroendocrine neoplasms confirmed by surgery and pathology between November 2005 and January 2023, were retrospectively analyzed. RESULTS: In the histopathological examination of 7277 appendectomy specimens, 11 cases (0.2%) had appendix neuroendocrine neoplasms. Among the 11 patients, 8(72.7%) were males, and 3(27.3%) were females, with an average age of 48.1 years. All patients underwent emergency surgery. A total of 9 patients underwent open appendectomy, including 1 patient who underwent second-stage simple right hemicolectomy after an appendectomy, and two who underwent laparoscopic appendectomy. All 11 patients were followed up for a period of 1 to 17 years. All patients survived without any indication of tumor recurrence. CONCLUSION: Appendiceal neuroendocrine neoplasms are low-grade malignant tumors originating from neuroendocrine cells. They are rarely seen in clinical practice and are often treated based on acute and chronic appendicitis symptoms. These tumors are challenging to diagnose before surgery due to the lack of specificity in clinical manifestations and auxiliary examinations. The diagnosis generally depends on postoperative pathology and immunohistochemistry. Despite the diagnostic challenges, these tumors have a favorable prognosis.

Eosinophil Granule Proteins Involvement in Acute Appendicitis-An Allergic Disease?

Several pieces of evidence point to an allergic component as a trigger of acute appendicitis. As the Th2 immune response is characterized by eosinophil mobilization to the target organ and release of their cationic granule proteins, it is reasonable to investigate if the degranulation of eosinophils could be associated with the local injury. The primary aim of this study is to evaluate the participation of eosinophils granules proteins in acute appendicitis, both at local and systemic levels and the secondary aim is to evaluate the diagnostic accuracy of eosinophils granules proteins for the detection of acute appendicitis, as well as for distinguishing between complicated and uncomplicated acute appendicitis. Eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP) and eosinophil peroxidase (EP) are the most well-known eosinophil granule proteins. From August 2021 to April 2022, we present a prospective single-center study to evaluate the EDN, ECP, and EP concentrations simultaneously in appendicular lavage fluid (ALF) and the serum of 22 patients with acute phlegmonous appendicitis (APA), 24 with acute gangrenous appendicitis (AGA), and 14 normal controls. Concerning EDN, no differences were found between groups. ECP concentrations in ALF and serum were significantly higher in the histologically confirmed acute appendicitis compared to the control groups (p < 0.0001 and p < 0.0001, respectively). In ALF, no differences were found between ECP levels in APA: 38.85 ng/mL (IQR 26.50-51.77) and AGA 51.55 ng/mL (IQR 39.55-70.09) groups (p = 0.176). In the serum, no difference was found between ECP levels at APA: 39 ng/mL (IQR 21.30-56.90) and AGA: 51.30 ng/mL (IQR 20.25-62.59) (p = 0.100). For EP, the concentrations in ALF (p < 0.001) and serum (p < 0.001) were both higher in acute appendicitis compared to the control. In ALF, no difference was found between APA: 240.28 ng/mL (IQR 191.2-341.3) and AGA: 302.5 (IQR 227.7-535.85) (p = 0.236). In the serum, no differences were found between APA: 158.4 ng/mL (IQR 111.09-222.1) and AGA: 235.27 (IQR 192.33-262.51) (p = 0.179). Globally, the ALF concentrations were higher than serum concentrations, reflecting an intense inflammatory local reaction in AA. The optimal ECP cut-off for discriminating between acute appendicitis and the controls was >11.41 ng/mL, with a sensitivity of 93.5%, but with a specificity for identifying appendicitis of 21.4%, good discriminative power (AUC = 0.880). For EP, the optimal cut-off was >93.20 ng/mL, with a sensitivity of 87%, but with a specificity of 14.3% (AUC = 0.901), excellent discriminative power. For the diagnosis of perforated AA, the discriminative power of ECP and EP serum concentrations are weak (AUC = 0.562 and AUC = 0.664, respectively). Concerning the presence of peritonitis, the discriminative power of ECP and EP serum concentrations is acceptable, respectively: AUC = 0.724 and AUC = 0.735. Serum levels of EDN (p = 0.119), ECP (p = 0.586) and EP (p = 0.08) in complicated appendicitis were similar to uncomplicated appendicitis. Serum concentrations of ECP and EP can be added to decision-making AA diagnosis. A Th2-type immune response is present in AA. These data bring forward the role of an allergic reaction in the pathogenesis of acute appendicitis.

The human vermiform appendix: morphological and anatomical review.

The article covers aspects of morphological, anatomical, embryological, histological aspects and origin, types, blood supply, innervation, lymph drainage of human vermiform appendix. The purpose of the study is to understand real function and to summarize this information for positive impact on clinical decision in case of appendicitis. Although characteristic features of normal and diseased appendix have been reported for many previous centuries, it still the most common challenge facing every day in operation room. The appendectomy, commonest surgical emergency procedure, may cause little confusion in surgeons due to highly variable situations of it inside the abdominal cavity. However, the recent imaging techniques have increased ability of surgeon for crucial diagnosis of the diseased appendix.

Interval appendicitis shows histological differences from acute appendicitis and may mimic Crohn disease and other forms of granulomatous appendicitis.

AIMS: While patients presenting with clinical signs and symptoms of acute appendicitis (AA) often receive surgical intervention shortly after presentation, certain patients may instead receive non-operative management initially, with appendectomy later. The histology of such interval appendicitis (IA) has only been described in small series. Also, we have noticed a recent increase in the incidence of IA specimens at our institution. METHODS AND RESULTS: We identified appendectomy specimens in our department during 2018 with available haematoxylin and eosin slides and electronic clinical data, and evaluated multiple histological findings. Cases were then divided into AA and IA, based on clinical history (AA if the patient presented to the hospital within 1 week of symptom onset and underwent appendectomy within 48 h; IA if appendectomy was delayed at least 1 week). Changes between groups were compared. The cohort included 165 cases (125 AA, 40 IA). Findings significantly more common in AA included mucosal acute inflammation, mural acute inflammation and acute serositis. Findings significantly more common in IA included Crohn-like mural inflammation, mural fibrosis, goblet cell hyperplasia, granulomas, xanthogranulomatous inflammation, haemosiderin-laden macrophages and granulation tissue. The rate of IA in 2018 (24%) was noticeably higher than in previous years. CONCLUSION: Acute inflammatory changes are more common in AA but can remain present in IA. Mural fibrosis, serosal adhesions, haemosiderin-laden macrophages and granulation tissue suggest IA. Granulomas and xanthogranulomatous inflammation can also be seen in IA, and Crohn-like mural inflammation is not uncommon. These histological patterns can guide signout and prevent diagnostic errors, particularly when clinical information is unavailable.

The association between appendicitis severity and patient age with appendiceal neoplasm histology-a population-based study.

PURPOSE: Recent studies have reported alarming appendiceal tumor rates associated with complicated acute appendicitis, especially in patients presenting with a periappendicular abscess. However, the data on histology of appendiceal tumors among acute appendicitis patients is limited, especially in patient cohorts differentiating between uncomplicated and complicated acute appendicitis. We have previously reported the association of increased appendiceal tumor prevalence with complicated acute appendicitis in this population-based study. The objective of this secondary analysis was to evaluate the association of both appendicitis severity and patient age with appendiceal tumor histology. METHODS: This nationwide population-based registry study (The Finnish Cancer Registry) was conducted from 2007 to 2013. All appendiceal tumors (n = 840) and available medical reports (n = 504) of these patients at eight study hospitals were previously evaluated, identifying altogether 250 patients with both acute appendicitis and appendiceal tumor. RESULTS: The severity of acute appendicitis was significantly associated with more malignant tumor histology. The risk of adenocarcinoma or pseudomyxoma was significantly higher among patients with periappendicular abscess (OR 15.05, CI 95% 6.98-32.49, p < 0.001) and patients presenting with perforated acute appendicitis (OR 4.09, CI 95% 1.69-9.90, p = 0.0018) compared to patients with uncomplicated acute appendicitis. Similarly, patient age over 40 years was significantly associated with the risk of adenocarcinoma and pseudomyxoma (OR 26.46, Cl 95% 7.95-88.09, p < 0.001). Patient sex was not associated with a more malignant appendiceal tumor histology (p = 0.67). CONCLUSION: More malignant appendiceal tumor histology of adenocarcinoma or pseudomyxoma was significantly associated with patient age over 40 years and complicated acute appendicitis, especially periappendicular abscess.

Outcomes of the Macroscopically Normal Appendix Left in Situ in Patients with Suspected Appendicitis.

BACKGROUND: Right iliac fossa (RIF) pain is a common indication for laparoscopy to diagnose and treat appendicitis. When a macroscopically normal appendix is found, there is no standard consensus regarding excision. Some surgeons remove the appendix due to the risk of microscopic inflammation and to avoid a future, repeat laparoscopy for possible appendicitis. Alternatively, others leave the appendix in situ to avoid morbidity from a potentially unnecessary procedure. We aimed to evaluate the outcomes of patients with macroscopically normal appendices left in situ. METHODS: All emergency laparoscopies without appendicectomy between January 1st 2010- December 31st 2020 were identified from theatre records. All operative notes were individually evaluated and comments on the macroscopic appearance of the appendix and any intra-operative pathology were recorded. Only patients undergoing laparoscopy for suspected appendicitis with macroscopically normal appendices were included. RESULTS: A total of 120 patients [median age 21.68 (range 9-90.8) years] were included. The cohort was predominantly female (n=105, 87.5%). Forty-eight patients (40.0%) had a positive finding during index laparoscopy. During a median duration of 94.5 (range 8-131) months' follow-up, 16 patients (13.33%) underwent a repeat laparoscopy for recurrent RIF pain. Thirteen (10.8% of total cohort) subsequently underwent an appendicectomy. Histology confirmed acute appendicitis in six cases (4.17% of entire cohort). On subanalysis of smaller cohort, index laparoscopies with no positive findings (n=72), nine patients (12.5%) underwent appendicectomy with two (2.7%) appendices demonstrating appendicitis on histological examination. CONCLUSION: 87% of the total cohort with a normal appendix at laparoscopy for RIF pain did not undergo further laparoscopy. Less than 5% of the total cohort and 2.7% of subanalysis cohort had an appendicectomy for histologically-proven appendicitis within the follow-up period. From the evidence in this study, we conclude that leaving the appendix in situ unless macroscopically inflamed is a viable alternative to excision.

IL-5 Serum and Appendicular Lavage Fluid Concentrations Correlate with Eosinophilic Infiltration in the Appendicular Wall Supporting a Role for a Hypersensitivity Type I Reaction in Acute Appendicitis.

Appendicitis is the most common abdominal surgical emergency, but its aetiology is not fully understood. We and others have proposed that allergic responses play significant roles in its pathophysiology. Eosinophils and Interleukin (IL)-5 are involved in a hypersensitivity type I reaction. Eosinophil infiltration is common in the allergic target organ and is dependent on IL-5. In the presence of an allergic component, it is expected that the eosinophil count and IL-5 local and systemic concentrations become elevated. To address this hypothesis, we designed a prospective study that included 65 patients with acute appendicitis (grouped as acute phlegmonous or gangrenous according to the histological definition) and 18 patients with the clinical diagnosis of acute appendicitis, but with normal histological findings (control group) were enrolled. Eosinophil blood counts and appendicular wall eosinophil infiltration were determined. IL-5 levels in blood and appendicular lavage fluid were evaluated. Appendicular lavage fluid was collected by a new methodology developed and standardized by our group. Appendicular wall eosinophil infiltration was higher in acute phlegmonous appendicitis than in gangrenous appendicitis (p = 0.000). IL-5 blood levels were similar in both pathologic and control groups (p > 0.05). In the appendicular lavage fluid, the higher levels of IL-5 were observed in the phlegmonous appendicitis group (p = 0.056). We found a positive correlation between the appendicular wall eosinophilic infiltration and the IL-5 concentrations, in both the blood and the appendicular lavage fluid, supporting the IL-5 reliance in eosinophil local infiltration. We observed the highest presence of eosinophils at phlegmonous appendicitis walls. In conclusion, the present data are compatible with a hypersensitivity type I allergic reaction in the target organ, the appendix, during the phlegmonous phase of appendicitis.

Case controlled study on diagnostic predictive value of inflammatory markers of complete blood count in pregnant women with acute appendicitis.

The aim of this study is to evaluate and compare the diagnostic ability of platelet-related parameters and white cell-based parameters in pregnant women with appendicitis. This is a retrospective case-controlled study. Women aged between 18 and 50-years-old who had undergone appendectomy between January 2010 and January 2021 were enrolled in the study. Age, pathological diagnosis and relevant laboratory parameters were recorded for each patient. Gestational characteristics were recorded for pregnant patients. There were 58 pregnant and 1171 non-pregnant women enrolled. Pregnant women with acute appendicitis were significantly younger (p < .0001, d= -0.532), had significantly lower PLT (p = .002, d= -0.428) and ALC (p = .033, d= -.304) levels but had significantly higher MPV (p = .004, d = .415) levels than non-pregnant counterparts. In pregnant women, only MPV was the independent predictor of acute appendicitis (OR: 1,952). MPV cut-off value of 9,6 fL provided 63,5% sensitivity, 67,7% specificity, 94,2% PPV and 17,3% NPV whereas 10 fL provided 55,8% sensitivity, 100% specificity, 100% PPV and 21,4% NPV for acute appendicitis in pregnant women. Therefore, MPV might be useful for diagnosing acute appendicitis in pregnant women.Impact statementWhat is already known on this subject? In pregnant women, counts and percentages of white blood cells and neutrophils are known to be independent predictors of acute appendicitis. Meanwhile, physiologic leukocytosis of gestation is a challenge for interpretation of these parameters. Platelets and related markers are, as well, predictive for inflammatory processes in the human body.What do the results of this study add? The role of platelet-related markers in the diagnosis of acute appendicitis in pregnant women has not been studied previously. The results of the present study indicate that in pregnant women, changes in mean platelet volume might be an independent predictor of acute appendicitis.What are the implications of these findings for clinical practice and/or further research? Further similar large-scale case-controlled or cohort studies are required to validate the present results. In pregnant women with abdominal pain, the use of mean platelet volume as a biomarker could reduce negative laparotomy rates. A mean platelet volume is a useful tool for diagnosing acute appendicitis in pregnant women and provides helpful guidance for clinicians dealing with these patients in the emergency room.

[Incidental Finding of Appendiceal Neuroendocrine Tumour]. / Zufallsbefund NEN Appendix.

With an incidence of 80%, neuroendocrine neoplasia (NEN) is the most common neoplasia of the appendix. In most cases, these tumours are diagnosed as an incidental finding after appendectomy with suspected appendicitis. They are usually highly differentiated neuroendocrine tumours. Due to their frequent location on the apex of the appendix, the NENs of the appendix are usually not the cause of the symptoms typical for appendicitis.Most patients (80-90%) receive adequate oncological treatment by laparoscopic or open appendectomy that has already been performed. However, if there are risk factors such as tumour size > 2 cm, location close to the base, angioinvasion, perforation or infiltration of neighbouring organs, proliferation index of > 2% or infiltration of the mesoappendix by more than 3 mm in the final histopathological finding, subsequent resection as an oncological right sided hemicolectomy is recommended .Due to their mostly early tumour stage at diagnosis without proven lymph node metastasis, patients with NEN of the appendix have an excellent 5-year survival rate of 70-85% across all tumour stages.

Urothelial Rests, Incidental Finding in a Patient with Acute Appendicitis: A Case Report and Literature Review.

Background: Urothelial rests, also known as Walthard rests, are benign nests of epithelial cells that most often are found in the female gynecologic tract. Only four of these urothelial rests have been described in the appendix. Case report: A 10-year-old female underwent an appendectomy for appendicitis. Histologically, there was acute appendicitis, and an incidental urothelial rest was identified, confirmed by immunostains positive for p63, CK7, and negative for synaptophysin. CD34 highlighted a rim of endothelial cells. Conclusion: Urothelial rests, which often appear in the female gynecologic tract, can occur in other sites such as the appendix. These benign lesions require differentiation from neuroendocrine lesions. The rim of endothelial cells in our report supports a vascular migrational origin.

PECULIARITIES OF MORPHOETIOPATHOGENESIS OF ACUTE APPENDICITIS AND CONSEQUENCES AFTER APPENDECTOMY.

OBJECTIVE: The aim: To study the features of morphoethiopathogenesis of acute appendicitis and the consequences after appendectomy. PATIENTS AND METHODS: Materials and methods: 10 preparations of human appendix were studied, from which 5 appendixes were normal in people who died in adulthood and old age and 5 processes were taken intraoperatively during appendectomy. Morphometric characteristics of the tissue structures of the preparations were compared with the systematic review data, the literature search by the following keywords: morphoethiopathy", "vermiform process", "lymphoepithelial formations", "digestive system", "lymphoid nodule", "Peyer's patches", "mucous membrane". RESULTS: Results: Pathogenesis of acute appendicitis - it is a consistent, staged process that is completely subject to the laws of exudative inflammation in response to microbial aggression. Removal of the appendicular process should be approached carefully and based on possible immunological consequences. Removal of the appendix as an immunocompetent organ Unreasonable removal of pathohistological unchanged appendix has medical consequences (can lead to consequences such as colon cancer) and not only. CONCLUSION: Conclusions: Our results suggest that the vermiform appendix retains its active function throughout human life. The study provides an overview with current knowledge about the etiology, pathogenesis and possible consequences of appendectomy as the main method of treatment of acute appendicitis. The search for ways to prevent appendicitis can be successful only by finding out the causes and factors that in some individuals cause the inability of the appendix to resist bacterial invasion. Appendix is necessary to fully support the immune responses of the digestive tract, but it belongs to the category of those organs, the loss of which during forced surgery does not cause significant damage to the body.

Appendiceal Neuroendocrine Tumor Mimicking Acute Appendicitis.

Appendiceal carcinoids are the most frequent tumors arising from the appendix, comprising between 32 and 57% of all the appendiceal tumors. The gross appearance of the appendix showed perforation at the tip with 30 ml of periappendicular collection. On histopathological examination, carcinoid tumor on the tip of appendix was found with tumor cells arranged in tubules, acini and nests infiltrating the muscularis propria and sub serosa. Perineural and vascular invasion was not seen. Immunohistochemistry for Synaptophysin was positive with Ki-67 labelling index of 2%. We present a case of appendiceal neuroendocrine tumor with the chief complaint of acute appendicitis.

Nonsurgical Management of Acute Appendicitis in Sickle Cell Disease.

A 9-year-old child with sickle cell disease (sickle beta zero thalassemia) was diagnosed to have acute appendicitis during a hospitalization for pain, acute chest syndrome, and exacerbation of asthma. Because of his high surgical risk, his appendicitis was treated nonsurgically, successfully deferring his appendectomy. He remains well after 1 year. This approach should be considered at least in other sickle cell patients with appendicitis, and perhaps other high-risk populations, if not all children with appendicitis.

Recurrent stump appendicitis.

Acute appendicitis is one of the most common reasons for abdominal surgery. Stump appendicitis, one of the rare complications of appendicitis surgery, is an inflammation that develops in the remaining part of the appendix following surgery and occurs at a rate of 1/50.000 in cases with appendectomy. Although patients manifest the same findings as those with acute appendicitis on physical examination and laboratory tests, the history of previous appendectomy may cause delays in diagnosis.. Complications such as perforation and peritonitis can develop if an early diagnosis cannot be made. In this article, we present the first case of recurrent stump appendicitis reported in the literature as far as we are aware.

The experiences of interval appendectomy for inflammatory appendiceal mass.

BACKGROUND: Interval appendectomy (IA) is a common treatment of acute appendicitis (AA) with inflammatory appendiceal mass (IAM). However, the management of patients with IAM is still controversial. The aim of this study was to assess the outcomes in patients with this condition. METHODS: We retrospectively evaluated 244 patients with AA for their clinical characteristics and outcomes. RESULTS: Forty-three patients had IAM at the first medical examination. The mean age was significantly younger and the C-reactive protein level significantly higher (12.6 vs 3.1 mg/dL) in patients with IAM. Thirty-four patients received IA, and nine received emergency appendectomy (EA). In the IA group, the diameter of the abscess was larger than in the EA group (31.4 vs 16.1 mm). The total length of hospitalization was longer in the IA group than the EA group (20.6 vs 7.0 days), although the operative time was longer in the EA group because of adhesion (101.1 vs 192.1 min). Furthermore, most IA patients received a reduced-port appendectomy (74% vs 11%). Recurrence occurred in approximately 15% of patients awaiting IA. There were no complications in either group. CONCLUSIONS: Although each treatment approach has its advantages and disadvantages, both IA and EA can be the first option for the treatment of AA with IAM.