ABSTRACT
BACKGROUND: The appendix is a small organ with no particular known function. Primary appendiceal neoplasms (ANs) are rare. While the prevalence is increasing worldwide over the past two decades, no apparent increase in the prevalence of ANs has been reported in the Arabian Gulf States. Recently, a significant decline in the age at diagnosis of some types of ANs has been reported worldwide, with a female predominance. OBJECTIVES: Evaluate the prevalence and clinicopathological characteristics of ANs within our institution in Saudi Arabia and compare them to limited existing studies from different regions as well as the Arabian Gulf States. DESIGN: Retrospective cohort. SETTING: Tertiary care center in Riyadh. PATIENTS AND METHODS: All patients who underwent appendectomy and had the appendix submitted for histopathological evaluation between May 2015 and June 2020 were included to allow for a follow-up of 5 years or more at the time of data collection. MAIN OUTCOME MEASURES: Demographics, clinical presentations, surgical interventions, histopathological findings, complications, and recurrence rates. SAMPLE SIZE: 25 AN patients. RESULTS: Of 1110 patients, 25 had ANs (13 female and 12 male participants) with a mean (standard deviation) age of 54.6 (14.1) years. Only 40% presented with acute appendicitis, 64% had comorbidities, and less than 50% underwent laparoscopic appendectomy. Histopathologically, 72% were low-grade appendiceal mucinous neoplasms (LAMNs). Complications were minimal grades (Clavien-Dindo classification), with 80% experiencing none. The mean hospital stay was 9.96 days. Local recurrence occurred in 8% of cases, and distant metastasis was documented in one adenocarcinoma case. However, the 5-year overall and disease-free survival rates were 88% and 80%, respectively. CONCLUSIONS: The incidence of ANs is increasing in Saudi Arabia with the higher prevalence of LAMNs. The pathological examination of the resected appendix played a pivotal role in the diagnosis of ANs. LIMITATIONS: Data collected retrospectively, a single institution, and a small population.
Subject(s)
Appendectomy , Appendiceal Neoplasms , Humans , Saudi Arabia/epidemiology , Male , Female , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/epidemiology , Appendiceal Neoplasms/surgery , Middle Aged , Retrospective Studies , Prevalence , Adult , Appendectomy/statistics & numerical data , Aged , Appendicitis/epidemiology , Appendicitis/pathology , Appendicitis/surgery , Neoplasm Recurrence, Local/epidemiology , Adenocarcinoma, Mucinous/epidemiology , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/surgeryABSTRACT
Late perforation of the ileum is a rare and potentially life-threatening complication following intestinal resection. We present a unique case of a woman in her 60s with a history of appendiceal carcinoid tumour, who underwent a right hemicolectomy. Positron emission tomography and surveillance CTs showed normal surgical changes and no recurrent malignancy. Three years postoperatively, she presented with severe abdominal pain. CT revealed a perforation along the ileal wall of the ileocolonic anastomosis. She underwent emergent resection and repeat ileocolonic anastomosis. We conclude that the patient had subclinical ischaemia of the anastomosis, which eventually progressed to perforation 3 years later. We discuss a literature review on late small intestinal anastomotic perforations and their associated risk factors. Our case and literature review emphasise the importance of considering delayed anastomotic leak in postoperative patients with a history of intestinal cancer, inflammatory bowel disease, Roux-en-Y enteroenterostomy or side-to-side anastomosis.
Subject(s)
Anastomosis, Surgical , Ileum , Intestinal Perforation , Humans , Female , Intestinal Perforation/etiology , Intestinal Perforation/surgery , Intestinal Perforation/diagnostic imaging , Anastomosis, Surgical/adverse effects , Middle Aged , Ileum/surgery , Colectomy/adverse effects , Carcinoid Tumor/surgery , Appendiceal Neoplasms/surgery , Postoperative Complications/surgery , Postoperative Complications/etiology , Postoperative Complications/diagnostic imaging , Anastomotic Leak/surgery , Anastomotic Leak/etiology , Tomography, X-Ray Computed , Abdominal Pain/etiologyABSTRACT
Low-grade appendiceal mucinous neoplasm (LAMN) is principally characterized by low-grade cytology without evidence of invasion to other organs. We report a LAMN surgical case whose appendiceal tumor penetrated the sigmoid colon wall. An 87-year-old man was referred for endoscopic resection (ER) of a colon polyp. Despite four ERs over 5 years, the polyp recurred at the same site. Laparoscopic surgery revealed a dilated appendix firmly attached to the sigmoid colon. We performed en bloc resection of both the sigmoid colon and appendix without tumor exposure. The histopathological evaluation showed that the LAMN had penetrated the sigmoid colon wall, forming two polyps on the colonic mucosa. In cases where the appendiceal-colonic fistula is suspected, en bloc resection of the appendix and colon wall should be considered.
Subject(s)
Adenocarcinoma, Mucinous , Appendiceal Neoplasms , Humans , Male , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/surgery , Appendiceal Neoplasms/diagnosis , Aged, 80 and over , Adenocarcinoma, Mucinous/surgery , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/diagnosis , Colon, Sigmoid/pathology , Colon, Sigmoid/surgery , Neoplasm InvasivenessABSTRACT
Introduction: Mucocoele of the appendix occurs in 0.2-0.7% of people in the world without any well-defined clinical symptoms. It occurs when there is an accumulation of mucous in the lumen of the appendix. Case Presentation: We present three cases: a 48-year-old male admitted to the emergency room with a one-day history of right iliac fossa pain. Abdominal examination was suggestive of acute appendicitis. The initial abdominal computerised tomography scan was reported as being unremarkable. At surgery, a firm tumour of the appendix was found, and a limited right hemicolectomy was done. Histopathology confirmed a mucocoele of the appendix with borderline mucinous histology.The second case is a 63-year-old man who presented with a one-year history of abdominal distension and weight loss. Previous abdominal ultrasound was suggestive of liver cirrhosis with significant ascitic fluid. Abdominal magnetic resonance imaging found an appendix mucocoele with infiltration of the omentum and scalloping of the liver surface suggestive of pseudomyxoma peritonei. A percutaneous biopsy of the omental mass confirmed metastatic mucinous adenocarcinoma of the appendix.The third case is a 68-year-old man who, during an annual medical check-up, had an incidental finding of a cystic right iliac fossa mass on ultrasound, confirmed on abdominopelvic computerised tomography scan to be an appendix mucocele. He had laparoscopic appendicectomy. The histopathological diagnosis confirmed a mucinous cystadenoma of the appendix. Conclusion: Preoperative diagnosis of appendiceal mucocoele is difficult and commonly discovered intraoperatively. The prognosis is good for the histologically benign type, but it is poor when malignant or peritoneal lesions are present. Funding: None declared.
Subject(s)
Appendix , Mucocele , Humans , Male , Middle Aged , Mucocele/surgery , Mucocele/diagnostic imaging , Mucocele/pathology , Appendix/pathology , Appendix/diagnostic imaging , Appendix/surgery , Aged , Tomography, X-Ray Computed , Appendiceal Neoplasms/surgery , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/diagnostic imaging , Adenocarcinoma, Mucinous/surgery , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/diagnostic imaging , Appendicitis/surgery , Appendicitis/diagnostic imaging , Appendectomy , Magnetic Resonance Imaging , Cecal Diseases/surgery , Cecal Diseases/pathology , Pseudomyxoma Peritonei/pathology , Pseudomyxoma Peritonei/surgeryABSTRACT
OBJECTIVE: To investigate the factors contributing to the blockage of perfusion tubes during hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with appendiceal pseudomyxoma peritonei (PMP) undergoing combined cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy treatment, and to construct a nomogram for predicting the risk of tube occlusion. STUDY DESIGN: Observational study. Place and Duration of the Study: Department of Gastrointestinal Surgery, Central Hospital Affiliated to Shandong First Medical University, Jinan, China, from June 2017 to December 2023. METHODOLOGY: Tube occlusion was defined as the inability to achieve 30 minutes of continuous unobstructed perfusion. Statistical methods such as univariate analysis, multivariate analysis, and Lasso regression were employed for data analysis. RESULTS: The results revealed that 27% of the 383 hyperthermic intraperitoneal chemotherapy perfusion treatments resulted in the tube occlusion events. Multivariate logistic regression analysis identified age, CA-125, CA19-9, and pathological type as the independent risk factors. A nomogram predicting the tube occlusion was constructed and validated for its predictive accuracy and clinical utility. CONCLUSION: This study successfully developed a nomogram to predict the tube occlusion risk during cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy treatment for patients with pseudomyxoma peritonei, providing valuable guidance for clinical practice and aiding in personalised treatment decisions to improve patient prognosis. However, further research is needed to validate the reliability and clinical applicability of the model, as well as to investigate the impact of tube occlusion on treatment outcomes and corresponding management strategies. KEY WORDS: Pseudomyxoma peritonei, Cytoreductive surgery, Hyperthermic intraperitoneal chemotherapy treatment, Tube occlusion, Nomogram.
Subject(s)
Cytoreduction Surgical Procedures , Hyperthermic Intraperitoneal Chemotherapy , Nomograms , Peritoneal Neoplasms , Pseudomyxoma Peritonei , Humans , Pseudomyxoma Peritonei/therapy , Pseudomyxoma Peritonei/drug therapy , Female , Male , Middle Aged , Peritoneal Neoplasms/therapy , Peritoneal Neoplasms/drug therapy , Adult , China , Appendiceal Neoplasms/therapy , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/drug therapy , Aged , Risk FactorsABSTRACT
BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP). AIMS AND OBJECTIVE: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians. RESULTS: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis. CONCLUSION: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm.
Subject(s)
Adenocarcinoma, Mucinous , Appendectomy , Appendiceal Neoplasms , Neoplasm Grading , Pseudomyxoma Peritonei , Tertiary Care Centers , Humans , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/surgery , Male , Female , Retrospective Studies , Middle Aged , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/surgery , Adenocarcinoma, Mucinous/diagnosis , Adult , Pseudomyxoma Peritonei/pathology , Pseudomyxoma Peritonei/surgery , Pseudomyxoma Peritonei/diagnosis , Aged , Appendix/pathology , Appendix/surgery , Mucins/metabolismABSTRACT
A 46-year-old female presented persistent right lower abdominal pain for 4 days. Computed tomography revealed an enlarged appendix with a surrounding low-attenuation mass. The patient was diagnosed with appendiceal abscess-forming appendicitis and initially treated with antibiotics. However, owing to the manifestation of nausea as a side effect, laparoscopic appendectomy was performed 3 days after the initial consultation. Intraoperative examination revealed mucinous material on the surface of the appendix and within the abdominal cavity, leading to the decision to perform an appendectomy with partial cecum resection and excision of the omentum with mucinous deposits. Pathological examination confirmed the diagnosis of a perforating low-grade appendiceal mucinous neoplasm and pseudomyxoma peritonei. The patient was subsequently referred to a specialized center for ongoing management, and at 9 months postoperatively, surveillance is being conducted. Low-grade appendiceal mucinous neoplasms can progress to pseudomyxoma peritonei through perforation; however, an optimal treatment approach has not yet been established. In particular, patients in advanced stages of the disease often require challenging management decisions. This case is reported along with a review of the literature to provide further guidance.
Subject(s)
Appendectomy , Appendiceal Neoplasms , Neoplasm Grading , Humans , Female , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/surgery , Middle Aged , Adenocarcinoma, Mucinous/surgery , Adenocarcinoma, Mucinous/diagnosis , Adenocarcinoma, Mucinous/pathology , Peritoneal Neoplasms/surgery , Peritoneal Neoplasms/pathology , Peritoneal Neoplasms/diagnosis , Tomography, X-Ray Computed , Pseudomyxoma Peritonei/surgery , Pseudomyxoma Peritonei/pathology , Pseudomyxoma Peritonei/diagnosisABSTRACT
Well-differentiated neuroendocrine tumors of the appendix (NETs) are rare in pediatric and adolescent age groups. However, they are the most common gastrointestinal epithelial tumor in this age group and the most common malignancy of the appendix in the general population. The classification of these tumors considers factors such as the proliferation index, size of the neoplasm, and the presence of perineural and/or lymphovascular invasion, which can contribute to distant metastases. Preoperative diagnosis is challenging, except in cases where patients exhibit symptoms of carcinoid syndrome or signs of metastatic disease, which are uncommon in pediatric and adolescent patients. For tumors smaller than 1 cm, appendectomy is usually curative, while larger tumors or those at risk of spreading may require right hemicolectomy with lymphadenectomy. We present a case of an adolescent with NET and provide a literature review on the diagnostic and therapeutic approaches that should be considered for this relatively rare condition.Key words. Adolescent age, appendix, neuroendocrine tumors, pediatric age.
Subject(s)
Appendectomy , Appendiceal Neoplasms , Appendicitis , Neuroendocrine Tumors , Adolescent , Humans , Appendectomy/methods , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/diagnosis , Appendiceal Neoplasms/surgery , Appendicitis/surgery , Appendicitis/diagnosis , Appendicitis/pathology , Colectomy/methods , Neuroendocrine Tumors/pathology , Neuroendocrine Tumors/diagnosis , Neuroendocrine Tumors/surgerySubject(s)
Adenocarcinoma, Mucinous , Appendiceal Neoplasms , Humans , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/mortality , Appendiceal Neoplasms/therapy , Adenocarcinoma, Mucinous/mortality , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/therapy , Survival Rate , PrognosisSubject(s)
Adenocarcinoma, Mucinous , Appendiceal Neoplasms , Humans , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/diagnosis , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/diagnosis , Peritoneal Neoplasms/pathology , Biopsy , Diagnosis, Differential , Biomarkers, Tumor/analysisABSTRACT
Low-grade appendiceal mucinous neoplasm (LAMN) may culminate as a mucin-secreting disease known as pseudomyxoma peritonei (PMP). Once the diagnosis of LAMN and PMP is made, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) are indicated.Herein, we present a female patient in her 50s who was diagnosed with an ovarian mass for which she underwent laparoscopic oophorectomy. As the pathology of the ovary showed a tumour of gastrointestinal origin, she then underwent CRS and HIPEC with a final pathology of LAMN. Six weeks later, a mucinous lesion confined to the abdominal wall was detected on a postoperative CT. Suspected for port-site metastasis at the laparoscopic trocar site, we treated this lesion using the same principles of treatment as the intra-abdominal disease. The abdominal wall mass was surgically resected, and the cavity created was irrigated with mitomycin C. On 30 months of follow-up, the patient had no evidence of disease.
Subject(s)
Appendiceal Neoplasms , Cytoreduction Surgical Procedures , Hyperthermic Intraperitoneal Chemotherapy , Laparoscopy , Ovarian Neoplasms , Ovariectomy , Humans , Female , Ovarian Neoplasms/therapy , Ovarian Neoplasms/pathology , Middle Aged , Ovariectomy/adverse effects , Laparoscopy/adverse effects , Cytoreduction Surgical Procedures/adverse effects , Hyperthermic Intraperitoneal Chemotherapy/adverse effects , Appendiceal Neoplasms/therapy , Appendiceal Neoplasms/pathology , Peritoneal Neoplasms/secondary , Peritoneal Neoplasms/therapy , Adenocarcinoma, Mucinous/therapyABSTRACT
BACKGROUND Fanconi anemia (FA) is a genetic disorder that impairs the function of the bone marrow and predisposes individuals to aplastic anemia. The condition is caused by mutations in genes responsible for DNA repair. People with FA have an increased risk of developing tumors due to DNA damage. Flat-cell carcinomas of the head, neck, esophagus, and genital organs are often observed in individuals with FA. CASE REPORT A 31-year-old man with Fanconi anemia and a history of bone marrow transplantation was admitted to the General Surgery Department due to elevated levels of the CEA marker. Before the transplantation, chromosomal anomalies, bone marrow hypoplasia, kidney agenesis, and bone defects were noted. After the transplantation, he developed a skin rash. He was also diagnosed with squamous cell carcinoma of the lip and chronic conditions, including cholestatic liver damage, hypertension, and hypothyroidism. During the diagnostic process, computed tomography showed signs of Barrett's esophagus, numerous polyps in the stomach and intestines, and a nodular formation measuring 4.5×5×5.5 cm in the right iliac region. Laparoscopy revealed a neoplasm of the appendix with numerous metastases on the inner abdominal wall and omentum. Histological analysis confirmed mucinous appendiceal cancer. The patient was discharged for palliative treatment at the Oncology Center with a final diagnosis of appendiceal cancer, mucinous type, grade G3. This case underscores the importance of early and comprehensive cancer screening in individuals with FA, particularly those with a history of bone marrow transplantation. CONCLUSIONS This clinical case underscores the critical importance of thorough and timely cancer diagnosis in individuals with this genetic pathology.
Subject(s)
Appendiceal Neoplasms , Fanconi Anemia , Humans , Male , Adult , Fanconi Anemia/complications , Appendiceal Neoplasms/complications , Neoplasms, Multiple Primary , Bone Marrow TransplantationABSTRACT
BACKGROUND: There is variation in the probability of nodal metastases from low-grade appendiceal adenocarcinomas, and the role of right colectomy is unclear. We aimed to define the prevalence and utility of lymphovascular invasion in predicting the risk of nodal metastases to help stratify patients who may benefit from right hemicolectomy. METHODS: Patients with nonmetastatic low-grade appendiceal adenocarcinomas were identified from the National Cancer Database (2010-2017). The primary outcome was probability of nodal metastases. Logistic regression was used to identify independent predictors of nodal metastases. A 4-tier risk model-the COH Composite Score-was calculated by assigning 1 point each for a high-risk feature (lymphovascular invasion, T3/T4 T stage, or nonmucinous histology). Survival analysis was performed using the Kaplan-Meier method. Multivariate Cox regression analysis was used to identify independent predictors of survival. RESULTS: A total of 1,303 patients with nonmetastatic low-grade appendiceal adenocarcinomas (64.2% mucinous) were identified. Of the 1,133 patients with known lymphovascular invasion status, 78 (6.9%) were lymphovascular invasion positive. In multivariate analysis, lymphovascular invasion was independently associated with nodal metastases (odds ratio, 8.68; P < .001). Overall accuracy of lymphovascular invasion in predicting nodal metastases was 86%. The COH Composite Score stratified patients in 4 categories with increasing risk of nodal metastases and incrementally worse survival. For patients with the COH Composite Score of 0 (12%), the nodal metastasis rate was 3.1%, and a right hemicolectomy in this group did not improve survival. CONCLUSION: The presence of lymphovascular invasion is strongly predictive of nodal metastases. Lymphovascular invasion as part of the COH Composite Score may help guide the extent of surgery in low-grade appendiceal adenocarcinomas.
Subject(s)
Adenocarcinoma , Appendiceal Neoplasms , Colectomy , Lymphatic Metastasis , Neoplasm Invasiveness , Humans , Colectomy/methods , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/surgery , Appendiceal Neoplasms/mortality , Male , Female , Aged , Middle Aged , Adenocarcinoma/surgery , Adenocarcinoma/pathology , Adenocarcinoma/mortality , Neoplasm Invasiveness/pathology , Retrospective Studies , Neoplasm Staging , Neoplasm Grading , Risk Assessment , Lymph Nodes/pathology , Lymph Nodes/surgerySubject(s)
Adenocarcinoma , Appendiceal Neoplasms , CDX2 Transcription Factor , Ovarian Neoplasms , Humans , Female , Ovarian Neoplasms/pathology , Ovarian Neoplasms/surgery , Ovarian Neoplasms/metabolism , Appendiceal Neoplasms/pathology , Appendiceal Neoplasms/surgery , Aged , Adenocarcinoma/pathology , Adenocarcinoma/secondary , Adenocarcinoma/surgery , Adenocarcinoma/metabolism , CDX2 Transcription Factor/metabolism , ColectomySubject(s)
Diagnostic Errors , Humans , Fecal Impaction/diagnostic imaging , Colonoscopy/methods , Gastrointestinal Stromal Tumors/diagnosis , Gastrointestinal Stromal Tumors/pathology , Cecal Neoplasms/diagnosis , Cecal Neoplasms/pathology , Cecal Neoplasms/surgery , Appendiceal Neoplasms/diagnosis , Appendiceal Neoplasms/pathology , Male , Appendix/pathology , Appendix/diagnostic imaging , Female , Middle AgedABSTRACT
Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by chronic activation of the immune system and a tendency to form tumorous lesions. IgG4-RD is frequently characterized by the presence of tumor-like masses affecting multiple organs and is easily mistaken for a malignant neoplasm. However, IgG4-RD affecting the appendix is extremely rare, with only seven cases reported previously. We report the case of a woman in her early 60s who presented with insidious abdominal pain and radiological findings mimicking appendiceal neoplasms. After diagnosing appendiceal neoplasms, surgery was performed. The patient had a serum IgG4 concentration of <1.35 g/L, which did not satisfy one of the three revised comprehensive diagnostic criteria for IgG4-RD. A pathological examination was conducted, and the patient was diagnosed with appendiceal IgG4-RD. To the best of our knowledge, there have been no previously reported cases of IgG4-RD affecting the appendix in patients with low serum IgG4 concentrations. This report may prove beneficial for the future understanding of IgG4-RD and for the revision of diagnostic and treatment strategies.
Subject(s)
Appendiceal Neoplasms , Immunoglobulin G4-Related Disease , Immunoglobulin G , Humans , Female , Appendiceal Neoplasms/diagnosis , Appendiceal Neoplasms/pathology , Immunoglobulin G4-Related Disease/diagnosis , Diagnosis, Differential , Middle Aged , Immunoglobulin G/blood , Tomography, X-Ray Computed , Appendix/pathology , Appendix/diagnostic imaging , Appendix/surgeryABSTRACT
Appendiceal neuroendocrine tumors (NETs) are common and often are identified as incidental lesions at the time of appendectomy. The guidelines for management are based on tumor size, degree of invasion, and the Ki67 proliferation index. Most small bowel NETs are composed of serotonin-producing EC-cells, but there are multiple other neuroendocrine cell types. In the rectum, there are L-cell tumors that express peptide YY (PYY), glucagon-like peptides (GLPs), and pancreatic polypeptide (PP); they are thought to have a better prognosis than serotonin-producing tumors. We investigated whether the appendix has distinct neuroendocrine tumor types based on cell type and whether that distinction has clinical significance. We collected 135 appendiceal NETs from the pathology archives of UHN Toronto and UHCMC (Cleveland). We analyzed the expression of biomarkers including CDX2, SATB2, PSAP, serotonin, glucagon (that detects GLPs), PYY, and pancreatic polypeptide (PP) and correlated the results with clinicopathologic parameters. Immunohistochemistry identified three types of appendiceal NETs. There were 75 (56%) classified as EC-cell tumors and 37 (27%) classified as L-cell tumors; the remaining 23 (17%) expressed serotonin and one of the L-cell biomarkers and were classified as mixed. EC-cell tumors were significantly larger with more extensive invasion involving the muscularis propria, subserosa, and mesoappendix compared with L-cell tumors. Mixed tumors were intermediate in all of these parameters. Both EC-cell and mixed tumors had lymphatic and/or vascular invasion while L-cell tumors had none. Unlike EC-cell NETs, L-cell tumors were not associated with lymph node metastasis. Tumor type correlated with pT stage and the only patient with distant metastatic disease in this series had an EC-cell tumor. Our study confirms that appendiceal NETs are not a homogeneous tumor population. There are at least three types of appendiceal NET, including EC-cell, L-cell, and mixed tumors. This information is important for surveillance of patients, as monitoring urinary 5HIAA levels is only appropriate for patients with serotonin-producing tumors, whereas measurement of GLPs and/or PP is more appropriate for patients with L-cell tumors. Our data also show that tumor type is of significance with EC-cell tumors exhibiting the most aggressive behavior.
Subject(s)
Appendiceal Neoplasms , Biomarkers, Tumor , Neuroendocrine Tumors , Humans , Appendiceal Neoplasms/pathology , Neuroendocrine Tumors/pathology , Neuroendocrine Tumors/metabolism , Neuroendocrine Tumors/diagnosis , Female , Male , Middle Aged , Adult , Aged , Biomarkers, Tumor/analysis , Aged, 80 and over , Young Adult , ImmunohistochemistryABSTRACT
BACKGROUND: Mucinous adenocarcinoma of the appendix (MACA) follows a complex disease course with variable survival. Large-scale predictive modeling may determine subtle yet important prognostic factors otherwise unseen in smaller cohort analyses. METHODS: Patients with MACA were identified from the Surveillance, Epidemiology, and End Results (SEER) Research Plus database (2005-2019). Primary, secondary, and tertiary outcomes were disease-specific survival (DSS), overall survival (OS), and average annual percent change (AAPC) in incidence. RESULTS: Among 4,258 included patients, MACA was most frequently diagnosed at 50 to 69 years (52.0%), with female preponderance (55.9%). MACA incidence AAPC was 3.8 (95% confidence interval [CI] 1.9-5.9). For patients with exclusive, first-diagnosis MACA included in survival analysis (3,222 patients), median DSS and OS were 118 and 88 months, respectively. In DSS-based multivariable analysis, worse prognosis was associated with non-Hispanic Black background (HR 1.36, 95% CI 1.02-1.82; p = 0.036), high grade (grade 3 HR 3.10, 95% CI 2.44-3.92; p < 0.001), lymphatic spread (HR 2.73, 95% CI 2.26-3.30; p < 0.001), and distant metastasis (HR 5.84, 95% CI 3.86-8.83; p < 0.001). In subcohort analysis of patients with rationale for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC, 2,387 patients), CRS-HIPEC was associated with survival benefit compared with surgery alone but only for moderate-grade tumors (median DSS/OS 138/138 vs. 116/87 months; p < 0.001). CONCLUSIONS: Mucinous adenocarcinoma of the appendix incidence is increasing in the United States. Survival rates are affected by both demographics and classical risk factors, and CRS-HIPEC-associated survival benefit predominantly occurs in moderate-grade tumors. Further exploration of biologic and clinicopathologic features may enhance risk stratification for this disease.