Referral and treatment pathways for pseudomyxoma peritonei of appendiceal origin within a national treatment programme

Surveillance of low-grade appendiceal mucinous neoplasms for progression to pseudomyxoma peritonei: Results from a structured surveillance programme

AIM

Low-grade appendiceal mucinous neoplasm (LAMN) of the appendix is a rare tumour that can progress to pseudomyxoma peritonei (PMP). There is a lack of standardization of surveillance following resection of LAMN as the progression rate to PMP is unclear. The aim of this study was to evaluate the rate of progression following resection of LAMN to PMP in a structured surveillance programme.

METHOD

Data for all patients referred for LAMN surveillance from 2013 to 2021 were retrospectively collected. The surveillance regime consisted of annual CT and tumour markers for a 5-year period. Patients who progressed to PMP were identified.

RESULTS

Of the patients enrolled in surveillance following appendicectomy and LAMN diagnosis (65.1% female, median age 56 years), 83 had completed at least 1 year of surveillance (median follow-up 24 months). Of these, 6% (n = 5) showed disease progression during follow-up. The median time to progression was 23 months. Survival analysis revealed no statistically significant difference in progression with regards to T staging (p = 0.39), margin positivity (p = 0.11) or appendiceal perforation (p = 0.26). No patients with Tis disease developed PMP. A statistically significant difference in progression was seen in patients with M1b staging (p = 0.021) and in those with mucin beyond the right iliac fossa at diagnosis (p = 0.04).

CONCLUSION

The observed progression rate justifies the necessity of postappendicectomy surveillance in patients with LAMN, with the risk of progression being highest within the first 3 years of diagnosis. The described surveillance programme allows for early detection of subclinical progression to PMP.

Two-stage cytoreductive surgery for 'extensive' pseudomyxoma peritonei: A legitimate alternative or salvage strategy?

BACKGROUND AND AIM

Two-stage cytoreductive surgery (CRS) has been proposed as an alternative to one-stage surgery in patients who have 'extensive' pseudomyxoma peritonei (PMP) and/or are unfit for very extensive surgery, to reduce morbidity. We review current evidence on two-stage CRS focusing on patient selection, interval between procedures, extent of surgery, use of HIPEC, perioperative and oncological outcomes.

METHODS

This is a narrative review. A literature search on PubMed and Embase was performed using keywords- 'Two-stage cytoreductive surgery', 'pseudomyxoma peritonei', 'high-volume PMP', 'huge PMP', 'cytoreductive surgery', 'HIPEC', 'staged surgery' and 'extensive pseudomyxoma peritonei'.

RESULTS

Five studies reported outcomes in a total of 114 patients. The indications for two-stage CRS were: in two studies, patients undergoing an incomplete cytoreduction due to undue surgical risk were reevaluated for a second surgery during routine surveillance; severe comorbidities in one; extensive disease with PCI>28 in another and in one, only HIPEC was performed as a second procedure due to intraoperative hemodynamic instability (the two-stage procedure was performed in interest of patient's safety). Major morbidity ranged from 0 to 37.5 % (first-stage) and 25%-38.9 % (second-stage). Short term follow-up demonstrated equivalent short-term oncological outcomes compared to historical data. Long term follow-up and quality-of-life data were not available.

CONCLUSIONS

The published studies showed different interpretations and applications of the two-stage CRS concept. The reported morbidity was similar to that after single-stage CRS for extensive PMP. Though short-term survival outcomes are acceptable, long-term follow-up is needed. Planned two-stage CRS should currently be reserved for highly selected clinical situations.

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.

Hyperthermic intraperitoneal chemotherapy in patients with incomplete cytoreduction for appendiceal pseudomyxoma peritonei: a 10-year treatment experience in China

BACKGROUND

To explore the application value of hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with incomplete cytoreduction for appendiceal pseudomyxoma peritonei (PMP).

METHODS

We retrospectively analyzed the clinical data of 526 patients with incomplete cytoreduction for appendiceal PMP to discover its prognostic factors, and the therapeutic value of HIPEC.

RESULTS

The 5-year and 10-year overall survival rates of patients after cytoreductive surgery (CRS) treated with HIPEC were significantly higher than those without HIPEC (5y-OS: 58% vs. 48%, 10y-OS: 37% vs. 16%, P = 0.032). The median progression-free survival (PFS) following CRS was 20 months, with a 20% 3-year PFS. The median PFS following CRS + HIPEC was 33 months, with a 60% 3-year PFS (P = 0.000). Univariate analysis indicated that HIPEC, gender, completeness of cytoreduction (CCR) and pathological grade had statistical difference. Multivariate analysis showed that CRS without HIPEC and high pathological grade were independent risk factors for poor prognosis and rapid tumor progression.

CONCLUSIONS

HIPEC may prolong the survival in patients with incomplete cytoreduction for low-grade appendiceal PMP. High pathological grade indicates poor survival and rapid tumor progression.

'It's just a mucocele': a case report of a massive appendiceal mucocele presenting as a left upper quadrant mass

Tumours of the appendix are very rare tumours that can and often present with a mucocele. This is a case report highlighting the associated pathology of appendix tumours and the management of a large mucocele. Specifically, how a right hemicolectomy is very rarely needed in these cases regardless of size and local anatomical relationships and some important considerations for the practicing surgeon in the non-tertiary centre that encounters a case like this.

Appendiceal collision tumors: case reports, management and literature review

Appendiceal tumors are incidentally detected in 0.5% cases of appendectomy for acute appendicitis and occur in approximately 1% of all appendectomies. Here, we report two cases of appendiceal collision tumors in two asymptomatic women. In both cases, imaging revealed right-lower-quadrant abdominal masses, which were laparoscopically resected. In both cases, histological examinations revealed an appendiceal collision tumor comprising a low-grade appendiceal mucinous neoplasm and well-differentiated neuroendocrine neoplasm (NEN). For complete oncological control, right hemicolectomy was performed in one patient for the aggressive behavior of NEN; however, histology revealed no metastasis. The other patient only underwent appendectomy. No further treatment was recommended. According to the latest guidelines, exact pathology needs to be defined. Proper management indicated by a multidisciplinary team is fundamental.

Incidental Diagnosis of Pseudomyxoma Peritonei After Emergent Splenectomy

Pseudomyxoma peritonei (PMP) is a rare disease associated with mucinous ascites. Pseudomyxoma peritonei has a low incidence and is difficult to diagnose. Pseudomyxoma peritonei usually presents with vague abdominal pain after significant progression. Computed tomography imaging is the most common modality for diagnosis; however, diagnosis as a result of surgical intervention in cases of acute abdomen has become increasingly common. We present a unique case of a 66-year-old man who was incidentally diagnosed with PMP after undergoing an emergent splenectomy for presumed blunt trauma. The patient presented to the emergency room with abdominal pain, shortness of breath, and diaphoresis. Computed tomography imaging revealed a splenic hematoma with suspicion of extravasation and a moderate amount of free intraperitoneal fluid consistent with blood. The patient was taken to the operating room emergently for an emergent splenectomy where splenic laceration was noted, as were multiple areas of nodularity in the omentum and cecum. Histologic evaluation of these lesions led to the diagnosis of PMP. After recovery from his initial splenectomy, the patient underwent exploratory laparotomy, cytoreductive surgery, cholecystectomy, removal of appendiceal mucocele, and hyperthermic intraperitoneal chemotherapy without complication. Final pathology was consistent with PMP and primary mucinous appendiceal adenocarcinoma. This case highlights an unusual presentation of PMP for a patient who was undergoing surgery for presumed splenic trauma. Surgeons must maintain a high index of suspicion and should perform histological evaluation when such unexpected findings are encountered.

Indications and outcomes for repeat cytoreductive surgery and heated intra-peritoneal chemotherapy in peritoneal surface malignancy

INTRODUCTION

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is offered in specialist centres as a treatment for peritoneal surface tumours. Despite its demonstrated efficacy, intra-abdominal recurrence occurs in 31-57% of patients. The aim of this study is to review the early and long-term outcomes in patients who undergo repeat CRS/HIPEC.

MATERIALS AND METHODS

A retrospective review of a prospectively maintained database of patients who had undergone repeat CRS/HIPEC for appendiceal neoplasms and colorectal peritoneal metastases (CRPM) from 2003 to 2019 was performed at a single specialist centre. Data pertaining to both short term outcomes and survival were evaluated.

RESULTS

Of 1259 patients who had undergone CRS/HIPEC, 84(6.7%) underwent repeat surgery: 45(53.6%) had pseudomyxoma peritonei (PMP) secondary to low grade appendiceal mucinous neoplasms (LAMN), 21(25.0%) had appendix carcinoma and 18(21.4%) had CRPM. Demographics, intra-operative findings and short-term outcomes were comparable across tumour types and between procedures. Median (95% CI) interval between procedures was 22.7(18.9-26.6) months and was comparable between tumour types. Median (95%CI) overall survival was not reached for the cohort overall or for those with PMP, but was 61.0(32.6-89.4) months for those with appendix cancer and 76.9(47.4-106.4) months for CRPM (p=<0.001). Survival was favourable in the PMP group (HR [95%CI] 0.044 [0.008-0.262]; p = 0.000) and unfavourable in the CC2-3 at index CRS procedure group (HR [95%CI] 25.612 [2.703-242.703]; p = 0.005).

CONCLUSION

Our findings demonstrate that repeat cytoredutive surgery with HIPEC can result in favourable survival, especially for patients with PMP when complete cytoreduction is achieved at index operation. We recommend that detailed patient assessment is performed through an expert multidisciplinary team meeting (MDT).

A retrospective analysis and literature review of neoplastic appendiceal mucinous lesions

Background

At present, the term mucocele is outdated, and mucinous appendiceal neoplasm is preferred. Mucinous appendiceal neoplasm is an uncommon pathology that occurs predominantly in middle-aged women. Its classification and management have been the subject of debate in recent decades. The aim of this study was to analyse the incidence, clinical management and survival of these tumours diagnosed in our centre in the last 10 years.

Methods

This was a retrospective observational study of patients with a diagnosis of appendiceal neoplasms between 2009 and 2018 in our centre. Variables such as sex, age, tumour type, clinical status, diagnosis, treatment and survival were collected. All data were analysed using the statistical program IBM SPSS Statistic® version 25.

Results

Twenty-nine patients with a diagnosis of appendiceal neoplasm were identified, and 24 corresponded to neoplastic appendiceal mucinous lesions (85.7%). The average age was 59.7 ± 17.6 years. Most patients were women (15 cases; 62.5%). Most of them presented with chronic abdominal pain (37.5%), and the diagnosis was performed by computed tomography (CT) (50%). The treatment was surgical in all cases. The surgical technique depended on the findings and histology of the tumour.

Conclusion

Mucinous appendiceal neoplasms are an uncommon entity, and their pathological classification and management have recently changed.