Beyond boundaries: Feasibility of curved linear array echoendoscope in appendiceal neoplasm detection

We recently read with great interest a study by Zhang et al in the World Journal of Gastroenterology. In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with endoscopic ultrasound (EUS) using different scopes. AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix. Clinically, they can present as nonspecific acute appendicitis. AMNs can turn into a life-threatening condition, termed pseudomyxoma peritonei, in which the ruptured appendix causes accumulation of mucin in the abdomen. Therefore, accurate and rapid diagnosis of AMN is essential. EUS is able to confirm and stage AMNs; although, EUS examination was once limited to the rectal and anal regions due to the conventional oblique-view scopes. With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes, the scope of examination is changing. Herein, we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.

A CT-based radiomics nomogram involving the cystic fluid area for differentiating appendiceal mucinous neoplasms from appendicitis with intraluminal fluid

OBJECTIVE

To develop and validate a radiomics nomogram based on computed tomography (CT) to distinguish appendiceal mucinous neoplasms (AMNs) from appendicitis with intraluminal fluid (AWIF).

METHOD

A total of 211 patients from two medical institutions were retrospectively analysed, of which 109 were pathologically confirmed as having appendicitis with concomitant CT signs of intraluminal fluid and 102 as having AMN. All patients were randomly assigned to a training (147 patients) or validation cohort (64 patients) at a 7:3 ratio. Radiomics features of the cystic fluid area of the appendiceal lesions were extracted from nonenhanced CT images using 3D Slicer software. Minimum redundancy maximum relevance and least absolute shrinkage and selection operator regression methods were employed to screen the radiomics features and develop a radiomics model. Combined radiomics nomogram and clinical-CT models were further developed based on the corresponding features selected after multivariate analysis. Lastly, receiver operating characteristic curves, and decision curve analysis (DCA) were used to assess the models' performances in the training and validation cohorts.

RESULTS

A total of 851 radiomics features were acquired from the nonenhanced CT images. Subsequently, a radiomics model consisting of eight selected features was developed. The combined radiomics nomogram model comprised rad-score, age, and mural calcification, while the clinical-CT model contained age and mural calcification. The combined model achieved area under the curves (AUCs) of 0.945 (95% confidence interval [CI]: 0.895, 0.976) and 0.933 (95% CI: 0.841, 0.980) in the training and validation cohorts, respectively, which were larger than those obtained by the radiomics (training cohort: AUC, 0.915 [95% CI: 0.865, 0.964]; validation cohort: AUC, 0.912 [95% CI: 0.843, 0.981]) and clinical-CT models (training cohort: AUC, 0.884 [95% CI: 0.820, 0.931]; validation cohort: AUC, 0.767 [95% CI: 0.644, 0.863]). Finally, DCA showed that the clinical utility of the combined model was superior to that of the clinical CT and radiomics models.

CONCLUSION

Our combined radiomics nomogram model constituting radiomics, clinical, and CT features exhibited good performance for differentiating AMN from AWIF, indicating its potential application in clinical decision-making.

Incidence of appendiceal neoplasms in appendectomy patients

BACKGROUND

Non-operative management has been suggested as a therapy for uncomplicated appendicitis. Notwithstanding, the risk of missing an appendiceal tumor must be considered, being the surgical piece crucial to rule out neoplasms. Therefore, we aim to determine the incidence of appendiceal neoplasms in patients with acute appendicitis, tumor types and the importance of the anatomopathological study of the surgical piece.

STUDY DESIGN

Retrospective study in which we described patients who underwent emergent appendectomy with histopathological findings of appendiceal neoplasms from January 2012 to September 2018. Descriptive analysis included demographic variables, diagnostic methods, and surgical techniques.

RESULTS

2993 patients diagnosed with acute appendicitis who underwent an emergency appendectomy. 64 neoplasms of the appendix were found with an incidence of 2,14%. 67.2% were women, the mean age was 46,4 years (± 19.5). The most frequent appendiceal neoplasms were neuroendocrine tumors (42,2%), followed by appendiceal mucinous neoplasms (35,9%), sessile serrated adenomas (18,8%), and adenocarcinomas (3,1%). In 89,1% of the cases, acute appendicitis was determined by imaging, and 14% of cases were suspected intraoperatively. Appendectomy was performed in 78,1% without additional procedures.

CONCLUSIONS

Appendiceal tumors are rare and must be ruled out in patients with suspected acute appendicitis. The incidence of incidental neoplasms is higher in this study than in the previously reported series. This information must be included in decision-making when considering treatment options for acute appendicitis.

The genetic profile and molecular subtypes of human pseudomyxoma peritonei and appendiceal mucinous neoplasms: a systematic review

Pseudomyxoma peritonei (PMP) is a rare, progressive, slowly growing neoplastic condition which is poorly understood, with a 5-year progression-free survival rate as low as 48%. PMP is most commonly caused by appendiceal mucinous neoplasms (AMN), and understanding their genetic biology and pathogenicity may allow for the development of better novel systemic treatments to target key deleterious mutations and the implicated pathways. The primary aim of this systematic review was to identify the genetic profile of histologically confirmed human PMP or AMN samples. The secondary aim was to identify whether genetic marks could be used to predict patient survival. Ovid EMBASE, Ovid MEDLINE, PubMed, and Web of Science were searched to identify studies investigating the genetic profile of histologically-confirmed human PMP or AMN samples. We review findings of 46 studies totalling 2181 tumour samples. The most frequently identified somatic gene mutations in patients with PMP included KRAS (38-100%), GNAS (17-100%), and TP53 (5-23%); however, there were conflicting results of their effect on survival. Three studies identified molecular subtypes based on gene expression profiles classifying patients into oncogene-enriched, immune-enriched, and mixed molecular subtypes with prognostic value. This review summarises the current literature surrounding genetic aberrations in PMP and AMNs and their potential utility for targeted therapy. Given the recent advances in clinical trials to directly target KRAS and GNAS mutations in other cancers, we propose a rationale to explore these mutations in future pre-clinical studies in PMP with a view for a future clinical trial.

Two methodologies of the rendezvous procedure to establish ureteral continuity from a delayed ureteral leak following pelvic surgery

BACKGROUND

Ureteral trauma recognized in the operating theater is managed, for the most part, at the same surgical procedure oftentimes with urologic consultation. A delayed urine leak presents unique problems in that direct access to the site of the leak is not possible except by a reoperative procedure.

METHODS

In patients who develop delayed urine leakage following cancer surgery, the leakage may be controlled by the collaborative efforts of a urologist and interventional radiologist. Success depends on placement of a nephroureteral stent by the rendezvous procedure.

RESULTS

The sequence of procedures to reestablish ureteral continuity following a delayed leak are important in the successful placement of a nephroureteral stent. In the first methodology, through a percutaneous nephrostomy, a guidewire is placed in the ureter and down to the ureteral defect. The guidewire is then recovered and advanced into the bladder using a ureteroscope and grasping forceps. A nephroureteral stent is placed over the guidewire to bridge the gap and stent the ureteral defect. In the second methodology, the urologist passed a guidewire into the distal ureter, out of the ureteral defect, and into the free peritoneal space. Under fluoroscopic control, the wire loop must snare the ureteral guidewire and pull it out at the percutaneous nephrostomy. The nephroureteral stent is passed over the ureteral wire into the bladder.

CONCLUSIONS

Two different methodologies were described to complete the rendezvous procedure. It can be successful a large percentage of the time with a delayed ureteral leakage. Success requires a combined interventional radiology and urologic procedure.

Peritonectomy of the colonic mesentery. Case report of a new surgical technology

Introduction and importance

Malignant peritoneal mesothelioma is a local-regional disease process that requires a comprehensive treatment plan including complete cytoreductive surgery and regional chemotherapy.

Case presentation

Treatments used in our patient began with a complete cytoreductive surgery. This required visceral resections, parietal peritonectomy, peritonectomy of the small bowel and its mesentery, and a peritoneal resection of the colonic mesentery with sparing of the major vasculature of the large bowel.

Clinical discussion

Peritoneal resection of the colonic mesentery and other treatments were performed in the absence of major complications. A 20-day hospitalization was required. The patient shows no internal hernias and no evidence of disease by CT follow-up at 4 years postoperatively. Her quality of life is excellent.

Conclusions

Malignant peritoneal mesothelioma was in the past a disease of limited survival without effective treatment options. Peritoneal resection of the colonic mesentery may be required for complete cytoreduction. A sequence of cytoreductive surgical procedures and regional chemotherapy treatments has made long-term survival possible.

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Malignant peritoneal mesothelioma has treatment options that combined surgery and regional chemotherapy.

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A major surgical challenge is complete mesenteric peritonectomy.

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Complete cytoreduction of the large bowel mesentery requires its resection with sparing major vasculature.

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Long-term survival is possible with low perioperative morbidity and mortality.

[Clinicopathologic characteristics of appendiceal mucinous tumor misdiagnosed as gynecological neoplasms]

Objective: To explore the clinicopathologic features and prognosis of female appendiceal mucinous tumor misdiagnosed as gynecological neoplasm. Methods: The clinical data of 12 cases of suspected gynecological neoplasm but confirmed as appendiceal mucinous tumor by operation and pathology in Beijing Obstetrics and Gynecology Hospital hospital from 2010 to 2019 were collected. The clinicopathologic features, treatment and prognosis of these patients were analyzed. Results: The median age of 12 patients was 58 years old and the clinical manifestations were atypical, including 5 cases with gastrointestinal symptoms, 6 cases with touched lesion in the right adnexal area, 3 cases with pseudomyxoma of peritonei, and 4 cases with increased serological tumor markers and ascites. Before operation, ultrasonic diagnosis showed cystic or cystic-solid mass in the right adnexal region in all cases. Pelvic and abdominal enhanced CT and/or enhanced MRI were performed in 5 cases. Two cases indicated possible origin of appendix and 1 case indicated lymphatic cystic tumor. Laparoscopic or laparotomy exploration was performed in all patients, during the operation 7 cases were performed appendectomy, 4 cases were performed tumor cell reduction and 1 case was treated in another hospital after laparotomy exploration. Eleven cases were diagnosed as low-grade appendiceal mucinous tumor and 1 case as appendiceal mucinous adenocarcinoma by postoperative pathology. Among the 11 patients with low-grade appendiceal mucinous tumor, 9 cases had no recurrence, 1 case lost follow-up, 1 case died of breast cancer and 1 case died 18 months after the operation. Conclusions: Gynecologists should improve their ability to differentiate appendiceal mucinous tumor from gynecological neoplasm. They can include ultrasonic diagnosis and CT scanning into their preoperative physical examination to improve their examination ability, and strive for specialist or surgical treatment to achieve the best result.

Clinicopathological Characteristics of Low-Grade Appendiceal Mucinous Neoplasm

INTRODUCTION

Recently, "low-grade appendiceal mucinous neoplasms" (LAMNs) have been proposed as one subtype of appendiceal mucinous neoplasms, characterized by a villous or flat proliferation of mucinous epithelium with low-grade cytologic atypia. The aim of this study was to clarify the clinicopathological characteristics of LAMN.

METHODS

In this multi-institutional cohort study, we retrospectively analyzed the clinicopathological characteristics in appendiceal neoplasms patients who underwent treatment from 2000 to 2017.

RESULTS

In total, 922 patients were enrolled, with 279 (30.3%) cases of LAMN, and 93 (10.1%) cases of non-LAMN disease. In comparison with patients with non-LAMN disease, those with LAMN had significantly lower levels of CA19-9 (p = 0.045), a lower frequency of T4 tumors (p < 0.0001), a lower frequency of lymph node metastasis (p < 0.0001), and a lower frequency of distant metastasis (p < 0.0001). Survival analysis revealed that patients with LAMN had a significantly better prognosis than did those with non-LAMN disease (p < 0.001). Among the patients with distant metastasis, those with LAMN had a significantly better prognosis than did those with non-LAMN disease (p = 0.0020), but among the patients without distant metastasis, the difference between the 2 groups was not significant (p = 0.26). However, among patients who underwent complete resection, the difference in prognosis between the 2 groups was not significant (p = 0.10).

CONCLUSIONS

A multicenter retrospective study revealed that the clinicopathological characteristics of LAMN was different from those of non-LAMN.

Rendezvous procedure to establish ureteral continuity from a delayed ureteral leak following pelvic surgery. A case report

BACKGROUND

Iatrogenic damage to the ureter as a result of an abdominal or pelvic surgical procedure is unusual. However, it does occur and the surgeon must be prepared to deal knowledgeably with the injury. Leaks that are recognized within the operating theater are managed, for the most part, at the same surgical procedure oftentimes with urologic consultation. A delayed leak presents unique problems in that direct access to the site of the leak is not possible except by a reoperative procedure. Delayed leaks present a clinical situation involving the urologist, interventional radiologist, as well as the surgeon.

METHODS

A patient who developed delayed urine leakage following a partial sacrectomy to remove recurrent mucinous appendiceal malignancy was studied. The leakage was controlled using a nephroureteral stent. Placement of the nephroureteral stent was made possible by the rendezvous procedure.

RESULTS

The sequence of procedures to reestablish ureteral continuity following a delayed leak are important in the successful placement of a nephroureteral stent. After establishing the site of the injury a percutaneous nephrostomy must be placed. Then, through the nephrostomy, a guidewire is placed in the ureter to be recovered and advanced into the bladder using a ureteroscope and grasping forceps. A nephroureteral stent is placed over the guidewire to bridge the gap and stent the ureteral defect.

CONCLUSIONS

The rendezvous procedure can be successful a large percentage of the time with a delayed ureteral leakage. Successful recovery of a guidewire in the ureter by ureteroscopy requires a combined interventional radiology and urologic procedure.

Peritoneal Metastases, a Frontier for Progress

The treatments for peritoneal metastases have evolved over 30 years. Now the concepts that guided clinicians are being tested in clinical trials to optimize standardized treatment regimens. The essential features of a successful management plan are cytoreductive surgery combined with cancer chemotherapy in a large volume of intraperitoneal fluid administered into the peritoneal space. The cytotoxicity of the cancer chemotherapy is maximized by moderate hyperthermia. The patients must be carefully selected using well-defined prognostic indicators. The efforts to date are multinational with centers of excellence located throughout the world.

Unusual case of intraluminal cecal recurrence of a low grade appendiceal mucinous neoplasm (LAMN)-Case report and brief literature review

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Penetration of the visceral peritoneum by a mucinous neoplasm consists the cardinal point in the management and prognosis.

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Patients with LAMN confined to the muscularis propria after histologic examination of the entire appendix (pTis) have essentially no risk of recurrence.

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There are no clear guidelines regarding appropriate management of appendiceal LAMNs with positive margins, especially when confined within the serosa.

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A simple cecectomy is traditionally suggested by some authors, but according to more recent data its necessity is debated.

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LAMN may rarely recur in the form of a polypoid protrusion into the cecal lumen and this may originate from the buried stump of the appendix on the ground of a positive margin.

Introduction

Appendiceal mucinous neoplasms exhibit a wide spectrum of clinical behavior, ranging from neoplasms which are relatively slow-growing but with considerable risk for recurrence and eventual death and those neoplasms that are highly aggressive with increased likelihood of early death. Clinical behavior depend mainly on mucinous neoplasms grading and staging.

Presentation of case

We present the incidental finding of a mucinous appendiceal neoplasm in a 52 years old woman during her follow up for an operated breast carcinoma. The patient underwent appendectomy and a low grade appendiceal mucinous neoplasm (LAMN) confined into the appendiceal wall was diagnosed. Resection margin showed fibrous replacement of the appendiceal wall and some acellular intraluminal mucin. Three months later the tumor recurred inside the cecal lumen and a right hemicolectomy was performed showing again a LAMN confined into the bowel wall.

Discussion

According to the latest AJCC eighth edition patients with pTis LAMN, as in our case, (LAMN confined to the muscularis propria after histologic examination of the entire appendix) have essentially no risk of recurrence. Moreover, some authors suggest follow up for LAMN confined into the appendix even with a positive surgical margin.

Conclusion

Rarely, LAMN may recur in the form of a polypoid protrusion into the cecal lumen and this recurrence may originate from the buried stump of the appendix, especially when the surgical margin is positive.

Peritoneal metastases invading the seminal vesicles: Radiologic appearance and outcome of treatment

BACKGROUND

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) may be of greatest benefit if all visible evidence of disease is resected. In some male patients the peritoneal metastases within the pelvis are invasive into the seminal vesicles and complete cytoreduction requires resection of these structures.

PATIENTS AND METHODS

From a prospective database of colorectal and appendiceal cancer patients who had CT evidence of seminal vesicle involvement and then had cytoreduction including resection of the seminal vesicles were reviewed. Their clinical features were tabulated.

RESULTS

Five patients were identified between ages 52 and 60. Three of 5 were appendiceal mucinous neoplasms and 4 of 5 had complete cytoreduction. Two of the patients are long-term survivors of 120 and 28 months. All patients are impotent and reported no return of sexual function over time. All five patients report normal micturition.

CONCLUSIONS

Resection of the seminal vesicles in a patient with invasion of these structures by peritoneal metastases is possible and should be considered in selected patients. This resection causes impotence but normal urination is to be expected.