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Deutsches Arzteblatt International Aug 2023Neoplasms of the vermiform appendix are rare. They comprise a heterogeneous group of entities requiring differentkinds of treatment. (Review)
Review
BACKGROUND
Neoplasms of the vermiform appendix are rare. They comprise a heterogeneous group of entities requiring differentkinds of treatment.
METHODS
This review is based on publications retrieved by a selective literature search in the PubMed, Embase, and Cochranedatabases.
RESULTS
0.5% of all tumors of the gastrointestinal tract arise in the appendix. Their treatment depends on their histopathologicalclassification and tumor stage. The mucosal epithelium gives rise to adenomas, sessile serrated lesions, adenocarcinomas,goblet-cell adenocarcinomas, and mucinous neoplasms. Neuroendocrine neoplasms originate in neuroectodermal tissue. Adenomasof the appendix can usually be definitively treated by appendectomy. Mucinous neoplasms, depending on their tumorstage, may require additional cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC). Adeno -carcinomas and goblet-cell adenocarcinomas can metastasize via the lymphatic vessels and the bloodstream and should thereforebe treated by oncological right hemicolectomy. Approximately 80% of neuroendocrine tumors are less than 1 cm in diameterwhen diagnosed and can therefore be adequately treated by appendectomy; right hemicolectomy is recommended if the patienthas risk factors for metastasis via the lymphatic vessels. Systemic chemotherapy has not been shown to be beneficial forappendiceal neoplasms in prospective, randomized trials; it is recommended for adenocarcinomas and goblet-cell adenocarcinomasof stage III or higher, in analogy to the treatment of colorectal carcinoma.
Topics: Humans; Appendix; Appendiceal Neoplasms; Prospective Studies; Hyperthermia, Induced; Adenocarcinoma; Appendectomy
PubMed: 37282595
DOI: 10.3238/arztebl.m2023.0136 -
Pathologica Feb 2021Neuroendocrine neoplasms of the appendix, colon and rectum are classified according to the most recent WHO classification as neuroendocrine tumors (NET), neuroendocrine... (Review)
Review
Neuroendocrine neoplasms of the appendix, colon and rectum are classified according to the most recent WHO classification as neuroendocrine tumors (NET), neuroendocrine carcinomas (NEC) and mixed neuroendocrine-non neuroendocrine neoplasms (MiNENs). NECs and MiNENs are aggressive neoplasms requiring multimodal treatment strategies. By contrast, NETs are, in most cases, indolent lesions occurring as incidental findings in the appendix or as polyps in the rectum. While most appendiceal and rectal NETs are considered relatively non-aggressive neoplasms, a few cases, may show a more aggressive clinical course. Unfortunately, clinical/pathological characteristics to select patients at high risk of recurrence/metastases are poorly consolidated. Diagnosis is generally easy and supported by the combination of morphology and immunohistochemistry. Differential diagnostic problems are for NECs/MiNENs with poorly differentiated adenocarcinomas, when immunohistochemical neuroendocrine markers are not obviously positive, whereas for NETs they are represented by the rare appendiceal tubular and clear cell variants (which may be confused with non-neuroendocrine cancers) and rectal L-cell tumors which may be chromogranin negative and prostatic marker positive.
Topics: Appendix; Carcinoma, Neuroendocrine; Colon; Humans; Infant, Newborn; Neoplasm Recurrence, Local; Neuroendocrine Tumors; Rectum
PubMed: 33686307
DOI: 10.32074/1591-951X-230 -
Nature Reviews. Gastroenterology &... Sep 2023The appendix is thought to have a role in the pathogenesis of ulcerative colitis, but the nature and basis of this association remains unclear. In this Perspective, we... (Review)
Review
The appendix is thought to have a role in the pathogenesis of ulcerative colitis, but the nature and basis of this association remains unclear. In this Perspective, we consider the biology of the appendix with respect to its immunological function and the microbiome, and how this relates to evidence that supports the involvement of the appendix in ulcerative colitis. In experimental models, removal of the inflamed appendix prevents colitis, and in human observational studies, appendectomy is associated with protection against ulcerative colitis. Further, among people who develop ulcerative colitis, appendectomy before diagnosis might influence the course and outcomes of the disease - some evidence suggests that it protects against colectomy but could increase the risk of colorectal cancer. Appendectomy after onset of ulcerative colitis seems to have disparate consequences. Clinical trials to understand whether appendectomy has a role in the treatment of ulcerative colitis are ongoing. Major questions about the role of the appendix in the pathogenesis of ulcerative colitis remain unanswered, and further research is needed to establish whether the connection is clinically relevant.
Topics: Humans; Colitis, Ulcerative; Appendix; Appendectomy; Colitis
PubMed: 37081213
DOI: 10.1038/s41575-023-00774-3 -
Human Pathology Feb 2023Low-grade appendiceal mucinous neoplasms are unique tumors of the appendix, characterized by low-grade mucinous epithelium with villiform, undulating, or flat... (Review)
Review
Low-grade appendiceal mucinous neoplasms are unique tumors of the appendix, characterized by low-grade mucinous epithelium with villiform, undulating, or flat architecture. These tumors lack infiltrative growth or destructive invasion, but can extend into the appendiceal wall by a "pushing" pattern of invasion, with a broad front that can mimic a diverticulum. These neoplasms have a propensity for peritoneal dissemination, resulting in the clinical presentation of pseudomyxoma peritonei. The pathologic staging of these neoplasms is challenging and fraught with confusing terminology and numerous classification systems. This review focuses on the AJCC pathologic staging of these tumors with a focus on challenging situations.
Topics: Humans; Peritoneal Neoplasms; Pseudomyxoma Peritonei; Appendiceal Neoplasms; Appendix; Neoplasms, Glandular and Epithelial
PubMed: 35843338
DOI: 10.1016/j.humpath.2022.07.004 -
Archives of Pathology & Laboratory... Jun 2021The 5th edition of the World Health Organization classification of digestive system tumors discusses several advancements and developments in understanding the etiology,... (Review)
Review
What is New in the 2019 World Health Organization (WHO) Classification of Tumors of the Digestive System: Review of Selected Updates on Neuroendocrine Neoplasms, Appendiceal Tumors, and Molecular Testing.
CONTEXT.—
The 5th edition of the World Health Organization classification of digestive system tumors discusses several advancements and developments in understanding the etiology, pathogenesis, and diagnosis of several digestive tract tumors.
OBJECTIVE.—
To provide a summary of the updates with a focus on neuroendocrine neoplasms, appendiceal tumors, and the molecular advances in tumors of the digestive system.
DATA SOURCES.—
English literature and personal experiences.
CONCLUSIONS.—
Some of the particularly important updates in the 5th edition are the alterations made in the classification of neuroendocrine neoplasms, understanding of pathogenesis of appendiceal tumors and their precursor lesions, and the expanded role of molecular pathology in establishing an accurate diagnosis or predicting prognosis and response to treatment.
Topics: Appendiceal Neoplasms; Appendix; Digestive System; Digestive System Neoplasms; Gastrointestinal Neoplasms; Genomics; Humans; Molecular Diagnostic Techniques; Neuroendocrine Tumors; World Health Organization
PubMed: 32233993
DOI: 10.5858/arpa.2019-0665-RA -
World Journal of Surgery Apr 2023Save for the contribution of Charles McBurney, who described his eponymous point and the appendicectomy incision, the history of appendicectomy is largely unknown among... (Review)
Review
BACKGROUND
Save for the contribution of Charles McBurney, who described his eponymous point and the appendicectomy incision, the history of appendicectomy is largely unknown among the medical profession. This review traces the history from the first anatomical depiction of the appendix to the development of open appendicectomy and the recent minimally invasive and non-operative methods.
METHODS
Historical articles, monographs and books containing anatomical descriptions of the vermiform appendix and reports of appendicitis and its surgical treatment were retrieved after searching the PubMed, Google Scholar and Embase databases from their inception to 31 March 2022.
RESULTS
The first inadvertent appendicectomy was performed during an operation for a groin hernia by Cookesley in 1731, and Mestivier was the first to drain a right iliac fossa abscess, due to appendicitis, in 1757. Krönlein performed the first appendicectomy for acute appendicitis in 1884 but his patient died. The first successful appendicectomy for acute appendicitis leading to patient survival was by Morton in 1887. In 1976, Wirschafter and Kaufman performed an inadvertent colonoscopic appendicectomy and, in 1980, Semm carried out the first laparoscopic appendicectomy. The first appendicectomy via a natural orifice (transgastric) appendicectomy was by Rao and Reddy in 2004.
CONCLUSION
This historical review charts the development of surgical knowledge concerning the management of appendicitis, from the first anatomical drawings of the appendix and descriptions of appendicitis to the development of surgical and conservative treatments up to the present day. It also corrects some inaccuracies of attribution in previous historical reviews.
Topics: Humans; Appendicitis; Appendectomy; Appendix; Acute Disease; Abscess; Laparoscopy
PubMed: 36581691
DOI: 10.1007/s00268-022-06874-6 -
JAMA Surgery Mar 2022Use of antibiotics for the treatment of appendicitis is safe and has been found to be noninferior to appendectomy based on self-reported health status at 30 days.... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
Use of antibiotics for the treatment of appendicitis is safe and has been found to be noninferior to appendectomy based on self-reported health status at 30 days. Identifying patient characteristics associated with a greater likelihood of appendectomy within 30 days in those who initiate antibiotics could support more individualized decision-making.
OBJECTIVE
To assess patient factors associated with undergoing appendectomy within 30 days of initiating antibiotics for appendicitis.
DESIGN, SETTING, AND PARTICIPANTS
In this cohort study using data from the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial, characteristics among patients who initiated antibiotics were compared between those who did and did not undergo appendectomy within 30 days. The study was conducted at 25 US medical centers; participants were enrolled between May 3, 2016, and February 5, 2020. A total of 1552 participants with acute appendicitis were randomized to antibiotics (776 participants) or appendectomy (776 participants). Data were analyzed from September 2020 to July 2021.
EXPOSURES
Appendectomy vs antibiotics.
MAIN OUTCOMES AND MEASURES
Conditional logistic regression models were fit to estimate associations between specific patient factors and the odds of undergoing appendectomy within 30 days after initiating antibiotics. A sensitivity analysis was performed excluding participants who underwent appendectomy within 30 days for nonclinical reasons.
RESULTS
Of 776 participants initiating antibiotics (mean [SD] age, 38.3 [13.4] years; 286 [37%] women and 490 [63%] men), 735 participants had 30-day outcomes, including 154 participants (21%) who underwent appendectomy within 30 days. After adjustment for other factors, female sex (odds ratio [OR], 1.53; 95% CI, 1.01-2.31), radiographic finding of wider appendiceal diameter (OR per 1-mm increase, 1.09; 95% CI, 1.00-1.18), and presence of appendicolith (OR, 1.99; 95% CI, 1.28-3.10) were associated with increased odds of undergoing appendectomy within 30 days. Characteristics that are often associated with increased risk of complications (eg, advanced age, comorbid conditions) and those clinicians often use to describe appendicitis severity (eg, fever: OR, 1.28; 95% CI, 0.82-1.98) were not associated with odds of 30-day appendectomy. The sensitivity analysis limited to appendectomies performed for clinical reasons provided similar results regarding appendicolith (adjusted OR, 2.41; 95% CI, 1.49-3.91).
CONCLUSIONS AND RELEVANCE
This cohort study found that presence of an appendicolith was associated with a nearly 2-fold increased risk of undergoing appendectomy within 30 days of initiating antibiotics. Clinical characteristics often used to describe severity of appendicitis were not associated with odds of 30-day appendectomy. This information may help guide more individualized decision-making for people with appendicitis.
Topics: Adult; Anti-Bacterial Agents; Appendectomy; Appendicitis; Appendix; Cohort Studies; Female; Humans; Male; Treatment Outcome
PubMed: 35019975
DOI: 10.1001/jamasurg.2021.6900 -
Cancers Jul 2023The vermiform appendix is a muscular cylindrical structure originating near the junction of the cecum and ileum, averaging 9 cm (5-35 cm) in size. As the most mobile... (Review)
Review
The vermiform appendix is a muscular cylindrical structure originating near the junction of the cecum and ileum, averaging 9 cm (5-35 cm) in size. As the most mobile viscera, it can adopt several positions, the most common being the retrocecal position. Perceived as an atavistic organ lacking physiological relevance, the vermiform appendix appears to be involved in immune function, serving in the maturation of B lymphocytes and the production of immunoglobulin A, in endocrine function, excreting amines and hormones in the 2-3 mL of mucus secreted daily, and in digestive function, by storing beneficial bacteria from where they can recolonize the colon. With a lumen of about 6 mm, the vermiform appendix has a reduced storage capacity, so any blockage of the appendix with fecoliths (fecaliths), seeds derailed from the colon, or enlarged lymph nodes prevents drainage and intraluminal accumulation of secreted mucus. Unable to relax, the appendix wall severely limits its intraluminal volume, so mucus accumulation leads to inflammation of the appendix, known generically as appendicitis. In addition, the vermiform appendix may be the site of the development of neoplastic processes, which may or may not involve mucus production, some of which can significantly affect the standard of living and ultimately lead to death. In general, mucinous tumors may have a better prognosis than non-mucinous tumors. This review takes a comprehensive path, starting by describing the anatomy and embryology of the vermiform appendix and further detailing its inflammatory pathologies, pathologies related to congenital anomalies, and appendix tumors, thus creating an up-to-date framework for better understanding, diagnosis, and treatment of these health problems.
PubMed: 37568688
DOI: 10.3390/cancers15153872 -
VideoGIE : An Official Video Journal of... Jul 2022Video 1Submucosal nodule in the cecum. After submucosal injection, a circumferential incision of the mucosa surrounding the lesion is performed with DualKnife (Olympus...
Video 1Submucosal nodule in the cecum. After submucosal injection, a circumferential incision of the mucosa surrounding the lesion is performed with DualKnife (Olympus America, Center Valley, Pa, USA). The fore-balloon of the double-balloon endoluminal interventional platform (DBEIP) is deployed and the edges of the circumferential incision are attached with 2 endoscopic clips to the long suture-loop mounted on the fore-balloon of the DBEIP. The fore-balloon is retracted in anal direction, pulling the lesion into the cecum. Careful endoscopic submucosal dissection is performed with DualKnife and HookKnife (Olympus America). Dissection is markedly facilitated by traction and continued until the entire appendix is pulled into the cecum. The tip of the appendix is separated from surrounding tissues, resulting in a full-thickness cecal wall defect. The suture-loop holding the resected appendix is cut with LoopCutter (Olympus America). The resected appendix is removed through DBEIP and the Overstitch endoscopic suturing device (Apollo Endosurgery, Austin, Tex, USA) is advanced into the cecum. The full-thickness defect in the cecal wall is completely closed with 2 continuous sutures. The final view demonstrates the entire resected appendix.
PubMed: 35815161
DOI: 10.1016/j.vgie.2022.03.010