Duplicated appendix complicated by appendiceal cancer

Case report: Acute appendicitis in appendix duplication

INTRODUCTION

Duplication of the appendix is a very rare presentation. According to the Cave-Wallbridge classification, there are three types of duplicate appendix.

PRESENTATION OF CASE

A 43 year old female presented with classical symptoms of acute appendicitis, with unremarkable inflammatory markers. The diagnosis was confirmed on pre-operative computer tomography (CT). During laparoscopy two tubular structures were identified: one arising from the tenia libera of the caecum adjacent to the terminal ileum and one retrocaecally at the confluence of the teniae. Both structures were excised using a laparoscopic linear stapler. Histopathological analysis demonstrated the accessory structure to be a microscopically unremarkable blind-ended tubular structure. The other specimen demonstrated acute gangrenous inflammation of the appendix. The patient had an uneventful recovery and was discharged home the following day.

DISCUSSION

Appendix duplication is rare; however, failure to recognise it in a patient with acute appendicitis could result in a retained source of sepsis, requiring subsequent re-exploration of the abdomen. The case presented here represents a Type B2 according to the Cave-Wallbridge classification and is the most susceptible to inadvertent error due to having appendixes in both typical and atypical anatomical locations. This case also highlights the probability of this diagnosis being missed on pre-operative CT.

CONCLUSION

This case report presents a unique opportunity for surgical trainees to review intra-operative laparoscopic images of a duplicate appendix, both to allow them to recognise this pathology if encountered in the future, and to embed the importance of ruling it out with thorough intra-operative examination.

Survival and prognostic factors for postoperative primary appendiceal cancer: a retrospective cohort study based on the Surveillance, Epidemiology, and End Results database

BACKGROUND

The factors affecting the postoperative survival of patients with primary appendiceal cancer (PAC) have yet to be fully explored. And there are no clear guidelines for adjuvant treatment after appendectomy. Whether chemotherapy can prolong patient survival after appendectomy, is critical in guiding postoperative medications. The majority of studies on appendiceal cancer are single case reports, and they focused on the incidence of appendiceal cancer. The present study aimed to investigate the survival characteristics of patients with primary appendiceal cancer after surgery using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

The data of 2,891 cases of primary appendiceal cancer between 2004 to 2015 were obtained from the SEER database and subjected to survival analysis using the Kaplan-Meier method and Cox proportional-hazards model. The annual percentage change (APC) was calculated using the weighted least squares method.

RESULTS

The overall age-adjusted incidence rate per 100,000 population steadily increased from 0.58 in 2004 to 1.63 in 2015. For patients who received chemotherapy, the median overall survival (OS) was 65 months and the 5-year OS rate was 51.9%, and for patients who did not receive chemotherapy or whose chemotherapy status was unknown, the median OS was not reached and the 5-year OS rate was 78.9%. Age [35< age <69: hazard radio (HR) =2.147; 95% confidence interval (CI): 1.442-3.197, P<0.001; age >69: HR =5.259; 95% CI: 3.485-7.937, P<0.001], race (White race: HR =0.728; 95% CI: 0.590-0.899, P=0.003), histologic type (mucinous neoplasm: HR =0.690; 95% CI: 0.580-0.821, P<0.001; malignant carcinoid: HR =0.657; 95% CI: 0.536-0.806, P<0.001), grade (II: HR =1.794; 95% CI: 1.471-2.187, P<0.001; III: HR =2.905; 95% CI: 2.318-3.640, P<0.001; IV: HR =3.128; 95% CI: 2.159-4.533, P<0.001), and stage (localized: HR =0.236; 95% CI: 0.194-0.287, P<0.001; regional: HR =0.425; 95% CI: 0.362-0.499, P<0.001) were identified as independent predictors of survival. And after adjusting for known factors (age, sex, race, tumor size, marital status, histologic type, grade, stage), chemotherapy (HR =1.220; 95% CI: 1.050-1.417, P=0.009) was revealed to be an independent indicator of poor prognosis.

CONCLUSIONS

There was an increasing trend in the incidence of appendiceal cancer in the United States between 2004 and 2015. Chemotherapy was revealed to be an independent indicator of poor prognosis, which provide valuable insight into the therapy of primary appendiceal cancer. Large clinical trials of chemotherapy and targeted therapy for appendiceal cancer are urgently needed.

Duplicate appendix complicated by low-grade appendiceal mucinous neoplasm: a rare case report and review of the literature

Low-grade appendiceal mucinous neoplasms (LAMNs) have been a very controversial tumor, and there is a lack of standardization for the optimal surgical procedure due to the infrequency of this disease. This is the first case report of duplicate appendix complicated by LAMN. The preoperative imaging examinations revealed that the mucinous tumor was shrinking spontaneously, allowing for safe laparoscopic resection. The histopathological findings indicated a dilated common base of the duplicated appendix, suggesting that the mucinous content drained spontaneously to the cecum. Further studies of the various complications of LAMNs are needed to establish the optimal surgical approach for LAMNs.

Appendiceal Duplication: A Comprehensive Review of Published Cases and Clinical Recommendations

BACKGROUND

Duplex appendix is very rare (incidence 0.004%) but has clinical relevance given the frequency of appendicectomies performed. Failure to recognise duplication can result in failure of treatment and medico-legal consequences. A review of published cases was undertaken to identify factors that may help in managing this rare condition.

METHODS

All English and non-English publications were identified in PubMed, Embase and Cochrane databases. Patient demographics, intraoperative findings, anatomical details and histopathology were analysed.

RESULTS

A total of 141 cases were identified [male/female ratio 1.4:1, median age 20 years (range foetus to 69 years)]. Duplication of the appendix ranges from branching of the appendix trunk to a fully matured appendix located elsewhere along the colon. Most can be categorised by the Cave-Wallbridge classification. There were 22 Type A, 8 Type B1, 46 Type B2 and 10 Type C cases (Cave-Wallbridge). There were six cases of horseshoe and two cases of triple appendix. Six reports gave anatomical descriptions that could not be classified by Cave-Wallbridge categories and in 11 cases there were no anatomical descriptions.

CONCLUSIONS

An anteriorly placed appendix, away from the convergence of the taenia, or a normal appendix in the presence of convincing clinical or radiological signs of appendicitis should instigate a careful examination of the caecal pole and possible exploration of the retrocaecal space for appendiceal duplication. If the patient had previous surgery for congenital abnormalities, Type B1 or Type C duplication should be considered.

Appendicitis in double cecal appendix: Case report

Double cecal appendix is a rare anatomical variation. Approximately 100 cases have been reported worldwide. It is usually diagnosed incidentally during emergency appendectomies due to inflammatory processes in the cecal appendix. Case presentation: male, white, 36 years old, obese, presenting with pain in the lower abdomen for 24 h followed by nausea, vomiting and mild fever. He was subjected to additional tests, with the leukogram showing leukocytosis and abdominal ultrasonography depicting cecal appendix with thickened wall, locally associated with small quantities of liquid and intestinal loop obstruction. He underwent laparotomy, revealing acute appendicitis. Another intestinal loop obstruction was identified next to the ileum, leading to recognizing another cecal appendix after local dissection. Double appendectomy and segmental iliectomy were performed although not needed. Results of the anatomopathological examination of the surgical samples showed acute inflammation in the two cecal appendices. So, performing a routine retroperitoneal release and a complete cecum evaluation during such surgical procedures is recommended and suggested due to the possibility of not identifying a second cecal appendix.

High-level microsatellite instability in appendiceal carcinomas

High-level microsatellite instability (MSI-high) is found in approximately 15% of all colorectal adenocarcinomas (CRCs) and in at least 20% of right-sided cancers. It is most commonly due to somatic hypermethylation of the MLH1 gene promoter region, with familial cases (Lynch syndrome) representing only 2% to 3% of CRCs overall. In contrast to CRC, MSI-high in appendiceal adenocarcinomas is rare. Only 4 MSI-high appendiceal carcinomas and 1 MSI-high appendiceal serrated adenoma have been previously reported, and the prevalence of MSI in the appendix is unknown. We identified 108 appendiceal carcinomas from MD Anderson Cancer Center in which MSI status had been assessed by immunohistochemistry for the DNA mismatch-repair proteins MLH1, MSH2, MSH6, and PMS2 (n=83), polymerase chain reaction (n=7), or both (n=18). Three cases (2.8%) were MSI-high, and 1 was MSI-low. The 3 MSI-high cases included: (1) a poorly differentiated nonmucinous adenocarcinoma with loss of MLH1/PMS2 expression, lack of MLH1 promoter methylation, and lack of BRAF gene mutation, but no detected germline mutation in MLH1 from a 39-year-old man; (2) an undifferentiated carcinoma with loss of MSH2/MSH6, but no detected germline mutation in MSH2 or TACSTD1, from a 59-year-old woman; and (3) a moderately differentiated mucinous adenocarcinoma arising in a villous adenoma with loss of MSH2/MSH6 expression, in a 38-year-old man with a strong family history of CRC who declined germline testing. When the overall group of appendiceal carcinomas was classified according to histologic features and precursor lesions, the frequencies of MSI-high were: 3 of 108 (2.8%) invasive carcinomas, 3 of 96 (3.1%) invasive carcinomas that did not arise from a background of goblet cell carcinoid tumors, and 0 of 12 (0%) signet ring and mucinous carcinomas arising in goblet cell carcinoid tumors. These findings, in conjunction with the previously reported MSI-high appendiceal carcinomas, highlight the low prevalence of MSI in the appendix as compared with the right colon and suggest that MLH1 promoter methylation is not a mechanism for MSI in this location.

Atresia of the appendix vermiformis: A rare case of developmental abnormality

Acute appendicitis, which requires immediate surgical intervention, is an important diagnosis in patients with acute abdomen. However, developmental abnormalities may interfere with the preoperative diagnosis and surgical treatment in some cases. Agenesis and atresia of the cecal vermiform appendix is an extremely rare clinical diagnosis. In addition, preoperative diagnosis may be difficult in some cases. Thus, diagnosis of the congenital absence of the vermiform appendix requires a thorough exploration of the retrocecal and ileocecal regions. A 59-year-old male was admitted from the emergency services with right lower abdominal pain. A celiotomy was performed with the suspicion of acute appendicitis. However, an atresia of the vermiform appendix was observed. The patient’s appendix was thus removed. Pathological examination confirmed suppurative appendicitis. This case underlines the importance of the clinical entity for surgeons who may deal with a similar case.