Adenocarcinoma of the appendix is rarely detected by colonoscopy

Survival outcomes used to validate version 9 of the American Joint Committee on Cancer staging system for appendiceal cancer

The standard for cancer staging in the United States for all cancer sites, including primary carcinomas of the appendix, is the American Joint Committee on Cancer (AJCC) staging system. AJCC staging criteria undergo periodic revisions, led by a panel of site-specific experts, to maintain contemporary staging definitions through the evaluation of new evidence. Since its last revision, the AJCC has restructured its processes to include prospectively collected data because large data sets have become increasingly robust and available over time. Thus survival analyses using AJCC eighth edition staging criteria were used to inform stage group revisions in the version 9 AJCC staging system, including appendiceal cancer. Although the current AJCC staging definitions were maintained for appendiceal cancer, incorporating survival analysis into the version 9 staging system provided unique insight into the clinical challenges in staging rare malignancies. This article highlights the critical clinical components of the now published version 9 AJCC staging system for appendix cancer, which (1) justified the separation of three different histologies (non-mucinous, mucinous, signet-ring cell) in terms of prognostic variance, (2) demonstrated the clinical implications and challenges in staging heterogeneous and rare tumors, and (3) emphasized the influence of data limitations on survival analysis for low-grade appendiceal mucinous neoplasms.

Duplication of the appendix masquerading as appendiceal tumor: a case report

BACKGROUND

This case report highlights the exceptional rarity of appendix duplication in adults, a condition that closely mimics appendiceal tumors, posing diagnostic challenges. The novelty of this case lies in its presentation of a Type A duplication, emphasizing the diagnostic intricacies involved in distinguishing it from other pathologies.

CASE PRESENTATION

We present the case of a 69-year-old male with a history of hypertension, hyperuricemia, and duodenal gastric ulcer, who presented with a positive occult blood test. Lower gastrointestinal endoscopy revealed an appendiceal orifice with atypical hyperemia and edema. Subsequent imaging and biopsy results suggested an appendiceal tumor, prompting laparoscopic ileocecal resection. Intraoperative findings revealed an unremarkable appendix, but histopathological analysis unveiled appendiceal duplication, characterized by bifurcation into two lumens within a thick serosal wall. The patient was discharged without complications.

CONCLUSIONS

This case underscores the importance of recognizing appendix duplication as a rare differential diagnosis for appendiceal tumors. Surgeons should remain vigilant, especially in cases of Type A duplication, where preoperative diagnosis remains challenging. Early identification can avert potential complications and missed congenital anomalies.

Mucinous appendiceal adenocarcinoma invading the bladder: not always an easy diagnosis. A case report

Appendiceal neoplasms account for less than 1% of intestinal cancers and their clinical manifestation is typically, nonspecific and ambiguous. Appendiceal tumor infiltrating the urinary tract is extremely rare and few cases are mentioned in literature. A 72-year-old woman presented gross hematuria and right colic pain. No prior urologic disease was reported. Cystoscopic examination showed a large lesion on the right side of posterior bladder wall, with multiple ulcerated areas and microscopical examination of the specimen revealed a mucinous adenocarcinoma infiltrating urinary bladder. Contrast-enhanced computed tomography (CT) scan identified focal thickening of bladder dome 21 × 7 cm with a possible origin from the appendix and with an unclear relationship with the uterus and the right fallopian tube. These findings were discussed with the local gastrointestinal multidisciplinary team, where a decision to perform upfront surgery was made. Explorative laparotomy confirmed a tumor of the appendix invading the urinary bladder. We performed an en-bloc resection including right colon, 40 cm of terminal ileum with a partial cystectomy removing the infiltrated area of the right bladder wall, and an omentectomy. Reconstruction was made first with a full-thickness suture of the bladder, then with an ileo-colon stapled anastomosis. The postoperative course was uneventful and the CT scan at 9 months from surgery did not show any recurrence. Right hemicolectomy is considered the gold standard for all lesions with invasion beyond the mucosa, and, appendicectomy alone seems to be the ideal treatment for in situ and localized cases.

Autoimmune encephalitis after surgery for appendiceal cancer: A case report

BACKGROUND

Primary cancer of the appendix is rare and often difficult to diagnose preoperatively due to the lack of specific clinical symptoms. Autoimmune encephalitis (AIE) is the most common cause of non-infectious encephalitis. The etiologies of AIE include tumors (paraneoplastic), infections (parainfections), or recessive infections. The tumors that have been reported to cause AIE include thymomas, ovarian teratomas, lung cancers, and breast cancers. However, there are no reports of AIE occurring after surgery for appendiceal cancer. This report describes the diagnosis and treatment of a patient with an appendiceal cancer and postoperative AIE.

CASE SUMMARY

We report the case of a 47-year-old man who was transferred to our hospital due to a recurrent low intestinal obstruction. Abdominal enhanced computed tomography was used to consider the possibility of a terminal ileal tumor with serous infiltration and lymph node metastasis. A right hemi-colectomy was performed under general anesthesia with an ileo-transcolon anastomosis and laparoscopic exploration. The postoperative pathologic evaluation revealed a high-grade goblet cell carcinoma of the appendix, accompanied by mesangial and abdominal lymph node metastases, and neural tube and vascular infiltration. The operation was completed without complication. The patient developed restlessness on postoperative day 4, and gradually developed a disturbance of consciousness on postoperative day 6. He was transferred to West China Hospital of Sichuan University and diagnosed with AIE.

CONCLUSION

Albeit rare, the occurrence of neurologic and psychiatric symptoms in patients with an appendiceal cancer postoperatively suggests the possibility of AIE.

Mutational profiles and prognostic impact in colorectal and high-grade appendiceal adenocarcinoma with peritoneal metastases

BACKGROUND

Next-generation sequencing (NGS) personalizes cancer treatments. In this study, we analyze outcomes based on NGS testing for colorectal cancer (CRC) and high-grade appendiceal adenocarcinoma (HGA) with peritoneal metastases.

METHODS

Retrospective review of genomic analyses and outcomes in patients with CRC or HGA with peritoneal metastases at a high-volume center from 2012 to 2019.

RESULTS

Ninety-two patients (57 CRC, 35 HGA) were identified. Overall survival was longer for CRC (52.8 vs. 30.5 months, p = 0.03), though rates of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) were similar. Multiple genes were more frequently mutated in CRC, including KRAS (51% vs. 29%, p = 0.04), TP53 (47% vs. 20%, p < 0.01), and APC (46% vs. 6%, p < 0.01). For CRC, multivariate regression showed an increased hazard ratio (HR) with increasing peritoneal cancer index (1.06 [1.01-1.11], p = 0.02) and a decreased HR following CRS/HIPEC (0.30 [0.11-0.80], p = 0.02). PIK3CA mutation associated with significantly increased HR (3.62 [1.06-12.41], p = 0.04), though only in non-CRS/HIPEC patients. Multivariate analysis in the HGA group showed a benefit following CRS/HIPEC (0.18 [0.06-0.61], p = 0.01) and for mucinous disease (0.38 [0.15-0.96], p = 0.04), while there was an increased HR with TP53 mutation (6.89 [2.12-22.44], p < 0.01).

CONCLUSION

CRC and HGA with peritoneal spread have distinct mutational profiles. PIK3CA and TP53 mutations are associated with survival for CRC or HGA with peritoneal metastases, respectively.

Preoperative prediction of malignancy and surgical treatment strategy in appendiceal tumors: multicenter review of 51 consecutive cases

PURPOSE

A diagnostic and treatment strategy for appendiceal tumors (ATs) has not been established. We aimed to evaluate our treatment strategy in ATs, including laparoscopic surgery (LS), and to identify preoperative malignancy predictors.

METHODS

A total of 51 patients between 2011 and 2021 were retrospectively reviewed. Data, including tumor markers and imaging findings, were compared between carcinoma and non-carcinoma patients. Validity of planned operation was evaluated based on pathological diagnosis.

RESULTS

Twenty-five patients were diagnosed with carcinoma, 13 with low-grade mucinous neoplasm, and 13 with other diseases. Symptoms were more commonly present in carcinoma patients than in non-carcinoma patients (68.0% vs. 23.1%, p = 0.001). Elevated CEA and CA19-9 were more frequently observed in carcinoma patients than in non-carcinoma patients (p < 0.01 and p = 0.04, respectively). Five carcinoma patients had malignancy on biopsy, compared with zero non-carcinoma patients. Significant differences were noted in the percentages of carcinoma and non-carcinoma patients with solid enhanced mass (41.7% vs. 0%, p < 0.001) and tumor wall irregularity (16.7% vs. 0%, p = 0.03) on imaging. Although the sensitivity was not high, the specificity and positive predictive value of these findings were 100%. Forty-two patients (82.4%) underwent LS as minimally invasive exploratory and/or radical operation, of whom 2 were converted to open surgery for invasion of adjacent organ. No patients had intraoperative complications or postoperative mortality.

CONCLUSION

Clinical symptoms, elevated tumor markers, and worrisome features of solid enhanced mass and tumor wall irregularity on imaging can be malignancy predictors. For management of ATs, LS is feasible and useful for diagnosis and treatment.

Misdiagnosed appendiceal mucinous neoplasms and primary ovarian mucinous tumors present with different pre- and intraoperative characteristics

Objective

To identify the differences between the pre- and intraoperative characteristics in misdiagnosed appendiceal mucinous neoplasms (AMNs) and those in primary ovarian mucinous tumors (POMTs) and to establish an effective model for differentiating AMNs from pelvic mucinous tumors.

Methods

This study enrolled 70 AMN patients who were misdiagnosed with ovarian tumors and 140 POMT patients who were treated from November 1998 to April 2021 at Peking Union Medical College Hospital. The clinical features and operative findings of the two groups of patients were collected and compared.

Results

There were significant differences in age and menopausal status, but no difference in the patients’ clinical manifestations between the two groups. The preoperative serum CA125 and CA199 levels were not different between the two groups. The CEA level (31.04 ± 42.7 vs. 7.11 ± 24.2 ng/ml) was higher in the misdiagnosed AMN group (P < 0.001). The AMNs were smaller than the POMTs that were measured preoperatively by ultrasonography (US) (P<0.05) and measured at surgery (P<0.05). Furthermore, the patients with AMNs more commonly had multinodularity and ascites noted on the preoperative US (P<0.001), on CT (P<0.001), and at surgery (P< 0.001). The two groups also differed in the presence of bilateral disease, in the appendiceal appearance and peritoneal dissemination. Subsequently, a prediction model was developed using multivariable logistic regression, which was evaluated through internal validation.

Conclusions

The suspicion of a nongenital organs originated tumor especially origing from appendiceal should be considered in a patient who is older, tumor size less than 12cm, multinodular, presence of mucinous ascites, and elevated serum CEA levels. Bilateral ovarian involvement, peritoneal dissemination, and an abnormal appendiceal appearance found during surgery were the typical features associated with AMNs.

Accidental discovery of appendiceal carcinoma during gynecological surgery: A case report

BACKGROUND

Malignant tumors of the appendix are extremely rare, constituting about 1% of all gastrointestinal tumors. Generally, pathology identifies these tumors during or after appendectomy because they are difficult to detect at the preoperative stage. This case report aims to introduce the definitive diagnosis and treatment of mucinous adenocarcinoma of the appendix.

CASE SUMMARY

A 49-year-old female patient came to our hospital with right lower abdominal pain, nausea, and vomiting for three days. There was no change in the menstrual cycle. Gynecological ultrasound showed a cystic, solid mass in the right adnexa. Abdominal enhanced computed tomography showed a thick appendix. Cancer was found on exploration of the appendix during gynecological surgery. The right colon was removed. After surgery, the patient received chemotherapy and is recovering well.

CONCLUSION

Appendiceal carcinoma is frequently found during or after surgery, and both preoperative examination and early evaluation of clinical manifestations are extremely important.

Demographic trends in the incidence of malignant appendiceal tumours in England between 1995 and 2016: Population-based analysis

AIMS

Recent data suggest that the incidence of malignant appendiceal tumours is increasing. This study aimed to determine temporal trends in the incidence of malignant appendiceal tumours within England and a possible influence by demographic factors.

METHODS

All incident cases of appendiceal tumours in patients aged 20 years and above were identified from the National Cancer Registration and Analysis Service database between 1995 and 2016 using ICD-9/10 codes. Cancers were categorized according to histology. Joinpoint regression analysis was used to investigate changes in age-standardized incidence rates by age, sex, histological subtype and index of multiple deprivation quintiles, based on socioeconomic domains (income, employment, education, health, crime, barriers to housing and services and living environment). Average annual per cent changes (AAPCs) were estimated by performing Monte-Carlo permutation analysis.

RESULTS

A total of 7333 tumours were diagnosed and 7056 patients were analysed, comprising 3850 (54.6 per cent) neuroendocrine tumours (NETs), 1892 (26.8 per cent) mucinous adenocarcinomas and 1314 (18.6 per cent) adenocarcinoma (not otherwise specified). The overall incidence of appendiceal tumours increased from 0.3 per 100 000 to 1.6 per 100 000 over the study interval. Incidence rate increases of comparable magnitude were observed across all age groups, but the AAPC was highest among patients aged 20-29 years (15.6 per cent, 95 per cent c.i 12.7-18.6 per cent) and 30-39 years (14.2 per cent, 12.2-16.2 per cent) and lowest among those aged 70-79 years (6.8 per cent, 5.7-8.0 per cent). Similar incidence rate increases were reported across all socioeconomic deprivation quintiles and in both sexes. Analysis by grade of NET showed that grade 1 tumours accounted for 63 per cent between 2010 and 2013, compared with 2 per cent between 2000 and 2003.

CONCLUSIONS

The incidence rate of malignant appendiceal tumours has increased significantly since 1995 and is mainly attributed to an increase in NETs. The increased diagnosis of low-grade NETs may in part be due to changes in pathological classification systems.

A proposal for changing nomenclature from pseudomyxoma peritonei (PMP) to abdomino-peritoneal mucinous carcinoma (APM) based on its long journey and experience from tertiary oncology center in India

Introduction

Pseudomyxoma peritonei (PMP) is a generalized term, usually known as “jelly belly” since 1884. Incidence is very low, 1–3 per million people per year. Because of its indolent nature, it is usually diagnosed at an advanced stage, thereby impacting the quality of life. The 5-year survival rate varies from 23 to 86% in world literature. Even 10 years and 20 years of survival have been described. With our experience, we like to propose rename of PMP as abdomino-peritoneal mucinous carcinoma (APM) as we strongly feel the time has come to specify the term and standardize the management strategy.

Methodology

In the premier institute of India and as a tertiary referral center, we experienced the maximum number of advanced cases of APM. From 2012 to 2021, we analyzed all the APM patients based on a prospectively maintained computerized database in the department of surgical oncology and found the reasons for renaming from this traditional one.

Results

We included a total of 87 patients who underwent surgical intervention. Thirty-five patients underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), and 52 patients underwent debulking. In CRS-HIPEC patients, CC-0 was achieved in 28 patients (80%), CC-1 in 4 patients (11.4%), and CC-2 in 3 patients (8.6%). Palliative intent HIPEC was done in 3 patients (8.6%). Clavien-Dindo grade III and IV morbidity was observed in 18.8% of patients with 90 days mortality of 5.7%.

Conclusion

With our long-term experience and advancement of scientific evidence, we like to propose a new name for PMP as APM. We strongly believe this paper will give a clear picture of this rare disease and standard management outlines.

Appendiceal Cancer in the National Cancer Database: Increasing Frequency, Decreasing Age, and Shifting Histology

BACKGROUND

Nonoperative management of acute appendicitis is increasingly common. However, small studies have demonstrated high rates of appendiceal cancer in interval appendectomy specimens. Therefore, we sought to identify national trends in appendiceal cancer incidence and histology.

STUDY DESIGN

The National Cancer Database was queried for patients 18 years or older, diagnosed with a right-sided colon cancer (including appendiceal) from 2004 to 2017 who had undergone surgery. Outcomes included trends in appendiceal cancer compared with right-sided colon cancers and trends in appendiceal cancer histology. Logistic regression was used to assess trends over time while adjusting for patient age, insurance, income, area of residence, and comorbidity. Predicted probabilities of the outcomes were derived from the logistic regression models.

RESULTS

Of 387,867 patients with right-sided colon cancer, 19,570 had appendiceal cancer and of those 5,628 had a carcinoid tumor. Odds of appendiceal cancer, relative to other right-sided colon cancers, increased from 2004 to 2017 (odds ratio [OR] 2.56, 95% CI 2.35-2.79). The increase occurred in all age groups; however, it was more markedly increased in patients 40-49 years old (2004: 10%, 95% CI 9-12 to 2017: 18%, 95% CI 16-20; pairwise comparisons p < 0.001). Odds of appendiceal carcinoid, relative to other appendiceal histologies, increased from 2004 to 2017 (OR 1.70, 95% CI 1.40-2.07) with the greatest increase in probability of a carcinoid in patients younger than 40 years old (2004: 24%, 95% CI 15-34 to 2017: 45%, 95% CI 37-53; pairwise comparisons p < 0.001).

CONCLUSION

Appendiceal cancer has increased over time, and the increase appears to be driven by a rise in carcinoids, most prevalent in patients 49 years of age or younger. When nonoperative management of acute appendicitis is undertaken, close follow-up may be appropriate given these findings.

Appendiceal tumors and pseudomyxoma peritonei: French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (RENAPE, RENAPATH, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of appendicular epithelial tumors (AT) and pseudomyxoma peritonei (PMP) published in March 2020, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org).

METHODS

All French medical societies specialized in the management of AT and PMP collaboratively established these recommendations based on literature until December 2019 and the results of a Delphi vote carried out by the Peritoneal Surface Oncology Group International experts, and graded into 4 categories (A, B, C, Expert Agreement) according to their level of evidence.

RESULTS

AT and PMP are rare but represent a wide range of clinico-pathological entities with several pathological classification systems and different biological behaviors. Their treatment modalities may vary accordingly and range from simple surveillance or laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) and / or systemic chemotherapy. The prognosis of these neoplasms may also largely vary according to their pathological grade and spreading at diagnosis or during the follow-up. Given the rarity of certain situations, the therapeutic strategy adapted to each patient, must be discussed in a specialized multidisciplinary meeting after a specialized pathological and radiological pre-therapeutic assessment and a clinical examination by a surgeon specializing in the management of rare peritoneal malignancies.

CONCLUSION

These recommendations are proposed to achieve the most beneficial strategy in a daily practice as the wide range and the rareness of these entities renders their management challenging. These guidelines are permanently being reviewed.

Mucinous adenocarcinoma of the appendix with inguinal node metastases

Mucinous adenocarcinoma of the appendix is a rare neoplasm with a low propensity for lymph node metastasis. The present case refers to an appendicular mucinous adenocarcinoma with inguinal lymph node metastasis. A 71-year-old woman underwent an appendectomy due to a clinical presentation of acute appendicitis. However, the histological examination of the surgical specimen revealed a mucinous adenocarcinoma of the appendix. After staging, the patient underwent a right hemicolectomy and was proposed for adjuvant chemotherapy. At the 3rd year of follow-up, inguinal lymphadenopathy was diagnosed, which biopsy confirmed inguinal node metastases from primary colorectal cancer, with areas of extracellular mucin. Restaging revealed liver and peritoneal metastasis, and the patient was proposed for palliative chemotherapy. Appendicular neoplasms, due to their rarity, represent a diagnostic and therapeutic challenge. This clinical case depicts an unusual metastasis pathway for an unusual neoplasm.

A rare case of synchronous appendiceal and cecal cancer

Primary appendiceal cancer is rare, and difficult to diagnose pre-operatively because lack of specific symptoms. This report presents a rare case of synchronous colon and appendiceal cancer. A 50-year-old man was referred to our hospital due to endoscopic submucosal resection (ESD) for early cecal cancer. ESD was performed, and the pathological examination revealed tubular adenocarcinoma with deep submucosal invasion. Laparoscopic ileocecal resection was performed as additional resection after ESD of cecal cancer. There were no obvious abnormalities around the ileocecal region in the preoperative examination. Postoperative pathological examination incidentally revealed a mucosal papillary adenocarcinoma of the appendix, with no residual lesion in the ESD scar. The patient was discharged on the seventh postoperative day. Synchronous appendiceal and colon cancer is extremely rare in past reports. Here, we report the case details and review previous case reports.

Lymph node positivity and association with long-term survival for different histologies of appendiceal cancer

BACKGROUND

Appendiceal cancers represent a diverse group of malignancies with varying biological behavior. The significance of lymph node metastases in relation to long-term survival and chemotherapy response is poorly defined.

METHODS

The National Cancer Database was queried to find patients diagnosed with appendiceal cancer from 1998 to 2012. Kaplan-Meier curves and multivariable Cox regression analyses were used to study the association between lymph node status and overall survival. Stage IV patients were excluded.

RESULTS

The rate of nodal positivity of the 9841 patients with known node status was: signet ring 47.4%, carcinoid 42.3%, nonmucinous adenocarcinoma 28.8%, goblet cell 21.9%, and mucinous adenocarcinoma 20.4%. Node-positive patients had worse long-term survival for all subtypes with the exception of carcinoid tumors (p < 0.001). The strongest association was for signet cell and goblet cell. Adjuvant chemotherapy in node-positive patients improved survival for mucinous, nonmucinous, and signet ring cell histology (p < 0.01), but not for goblet cell.

CONCLUSIONS

Nodal involvement in patients with appendiceal cancer varies in incidence, association with adverse survival, and response to systemic therapy. Individualized treatment algorithms for the management of the subtypes of appendiceal cancer are needed.

Risk of appendiceal neoplasm after interval appendectomy for complicated appendicitis: A systematic review and meta-analysis

BACKGROUND

Non-operative management is often the treatment of choice in cases of complicated appendicitis and routine interval appendectomy is not usually recommended. Actually, recent studies show an alarming number of appendiceal neoplasms following interval appendectomy. The aim of this study is to evaluate the prevalence of appendiceal neoplasms and their histological types after interval appendectomy for complicated appendicitis in adults.

METHODS

A comprehensive literature search of the PubMed, Scopus and Web of Science databases was conducted according to the PRISMA statement. Studies reporting appendiceal neoplasm rates after interval appendectomy and histopathological characteristics were included. The most recent World Health Organization (WHO) classification of malignant tumours was considered. A pooled prevalence analysis for both prevalence and pathology was performed.

RESULTS

A total of eight studies was included: seven retrospective series and one randomized controlled trial. The pooled prevalence of neoplasms after interval appendectomy was 11% (95% CI 7-15; I² = 37.5%, p = 0.13). Appendiceal mucinous neoplasms occurred in 43% (95% CI 19-68), adenocarcinoma in 29% (95% CI 6-51), appendiceal neuroendocrine neoplasm in 21% (95% CI 6-36), globet cell carcinoma in 13% (95% CI -2-28), adenoma or serrated lesions in 20% (95% CI -0-41) of cases.

CONCLUSION

The risk of appendiceal neoplasm in patients treated with interval appendectomy for complicated appendicitis is 11%; mucinous neoplasm is the most common histopathological type. Further studies should investigate this association in order to clarify the biological pathway and clinical implications.

A general overview of mucocele of appendix

Mucocele of the appendix is a very rare disease entity that often discovered incidentally during surgery. It can result from both non-neoplastic and neoplastic lesions and histopathological examination is needed for confirmation. Failure to make an early preoperative diagnosis may results in its rapture and spillage of mucin contents into the peritoneal cavity leading to a disastrous complication of pseudomyxoma peritonei (PMP) that has a very bad prognosis. A clear pathological terminology and management strategies of appendiceal mucocele (AM) is lacking. This literature review aims to derive detailed information related to clinical significance of AM to avoid complication of PMP and plan appropriately during surgery according to the current evidence. The relevant articles from scientific databases such as Medline, PubMed, Google Scholar were searched and extracted using the keywords “mucocele appendix” “cystadenoma%”. Data based on epidemiology, clinical manifestations, complications, pathology, diagnostic work up and management were analyzed and summarized. A meticulous surgical excision is the mainstay of treatment and open surgical approach is still preferred over laparoscopy. Preoperative diagnosis of AM is very imperative as it may harbour neoplasm and can be made utilising the imaging tools like computed tomography and ultrasonography. Primary care physicians can have a crucial role in making early detection and timely referral for appropriate management in order to avoid complications. After appendectomy, 5-year survival rate for the simple AM is 91%-100% but it reduces to 25% for the malignant AM.

Very rare presentation of perforated appendiceal adenocarcinoma within a prolapsed colostomy

Appendiceal adenocarcinoma is rare with variable presentations. Perforation of the appendix within prolapsed ostomy can have peritoneal spread for which intraperitoneal chemotherapy should be considered. Surveillance is essential for these patients.

Quality analysis of operative reports and referral data for appendiceal neoplasms with peritoneal dissemination

BACKGROUND

Peritoneal metastasis from appendiceal neoplasms is a rare disease usually found unexpectedly and is associated with deficits in quality reporting of findings.

METHODS

Retrospective review of our appendiceal peritoneal metastases carcinomatosis database evaluating quality of index operative and pathology reports. Operative report quality was graded by 2 standards; general quality, based on Royal College of Surgeons quality metrics and peritoneal metastases assessment. Pathology report quality was assessed by the accuracy of diagnosis.

RESULTS

Three hundred and seventy-five index operative reports and 490 outside pathology reports were reviewed. General quality of the index operative reports was excellent, with nearly 80% of reports encompassing all the Royal College of Surgeons quality metrics. Peritoneal metastases assessment was poor. Forty-four percent of the reports performed no peritoneal evaluation, while 48.3% only involved partial peritoneal evaluation. Only 7.7% of the reports performed a complete evaluation. Of the pathology reports, 48.4% had discrepancies with final pathologic findings. Low-grade disease and high-grade disease were misdiagnosed 36.06% and 62.7% of the time, respectively. Discordant treatment occurred in 15.3% and 30.0% of cases for misdiagnosed low-grade and high-grade disease, respectively. Incomplete cytoreduction was attempted in nearly a third of referral cases, which was associated with a significantly increased risk for ultimate incomplete cytoreduction with an odds ratio of 4.72.

CONCLUSION

This review finds that referral operative reports' descriptions of the technical aspects of a procedure is usually complete. However, oncologic parameters and descriptions of peritoneal metastases are frequently incomplete. Further, pathology reports from outside institutions can lead to inappropriate clinical management decisions. We propose a simplified algorithm to assist nonperitoneal surface malignancy surgeons.

Primary Appendiceal Adenocarcinoma Presenting with Hematochezia due to the Invading Tumor in the Sigmoid Colon

Primary appendiceal tumors are rare malignancies; some cases have been described to invade other organs, and this represents a very rare clinical condition. We report a case of appendiceal adenocarcinoma invading the sigmoid colon and a review of similar cases. A 69-year-old woman with complaints of hematochezia was admitted to the hospital. Colonoscopy revealed a tumor in the sigmoid colon, which was a well-differentiated tubular adenocarcinoma. A computed tomography scan showed an appendiceal mass that involved the sigmoid colon, suggesting an appendiceal cancer invading the sigmoid colon. Ileocecal resection with extended lymphadenectomy and en bloc resection of the sigmoid colon was performed. The appendiceal tumor involved the sigmoid colon and the terminal ileum. The ileocecal part which included the tumor and the involved sigmoid colon was resected in total. Macroscopic findings showed that the appendiceal tumor made a fistula with the sigmoid colon. Pathological examination revealed that the tumor was a well-differentiated tubular adenocarcinoma that invaded the sigmoid colon. The final pathological stage was T4bN0M0, stage IIC. The patient was discharged from the hospital uneventfully. She was alive without relapse after a 20-month follow-up. Although an appendiceal tumor invading the rectosigmoid region is rare, a preoperative diagnosis can be obtained that facilitates the planning of a suitable surgical procedure: en bloc resection of the ileocecal part and the rectosigmoid part.

Prognostic Molecular Classification of Appendiceal Mucinous Neoplasms Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Appendiceal mucinous neoplasm (AMN) with peritoneal metastasis is a rare but deadly disease with few prognostic or therapy-predictive biomarkers to guide treatment decisions. Here, we investigated the prognostic and biological attributes of gene expression-based AMN molecular subtypes.

METHODS

AMN specimens (n = 138) derived from a population-based subseries of patients treated at our institution with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) between 05/2000 and 05/2013 were analyzed for gene expression using a custom-designed NanoString 148-gene panel. Signed non-negative matrix factorization (sNMF) was used to define a gene signature capable of delineating robustly-classified AMN molecular subtypes. The sNMF class assignments were evaluated by topology learning, reverse-graph embedding and cross-cohort performance analysis.

RESULTS

Three molecular subtypes of AMN were discerned by the expression patterns of 17 genes with roles in cancer progression or anti-tumor immunity. Tumor subtype assignments were confirmed by topology learning. AMN subtypes were termed immune-enriched (IE), oncogene-enriched (OE) and mixed (M) as evidenced by their gene expression patterns, and exhibited significantly different post-treatment survival outcomes. Genes with specialized immune functions, including markers of T-cells, natural killer cells, B-cells, and cytolytic activity showed increased expression in the low-risk IE subtype, while genes implicated in the promotion of cancer growth and progression were more highly expressed in the high-risk OE subtype. In multivariate analysis, the subtypes demonstrated independent prediction power for post-treatment survival.

CONCLUSIONS

Our findings suggest a greater role for the immune system in AMN than previously recognized. AMN subtypes may have clinical utility for predicting CRS/HIPEC treatment outcomes.

Tubulo-villous adenoma of the appendix: A case report and review of the literature

•

Tubulo-villous adenoma is a rare benign appendiceal neoplasm.

•

This neoplasm is often asymptomatic and occasionally discovered at surgery.

•

Acute appendicitis is the most common clinical presentation.

•

Pre-operative diagnosis, even with the help of radiological imaging, is difficult.

•

Appendectomy is considered the correct treatment.

Introduction

Tubulo-villous adenoma is a rare benign appendiceal neoplasm often asymptomatic with the most clinical manifestation that resembles acute appendicitis. Pre-operative diagnosis is difficult by its rarity and the absence of typical symptoms. Adequate treatment is surgical resection.

Presentation of case

A 69-year-old male was admitted to the Emergency Department with a two-day history of abdominal pain associated with constipation. Abdominal examination revealed abdominal pain localized, at deep palpation, in the right iliac fossa and in hypogastrium without obvious muscle guarding or rebound tenderness. Laboratory tests showed a normal white blood cell count with 82.3% neutrophils and high C-reactive protein level. After a negative abdominal ecography, the patient was evaluated by abdominal computed tomography, which revealed acute appendicitis. The patient was submitted to surgery and open appendectomy was performed. The post-operative course was uneventful and the patient was discharged on the 5^th post-operative day.

Discussion

Acute appendicitis may be a clinical manifestation of a benign appendiceal neoplasm. Pre-operative radiological investigations not always are useful for an early diagnosis that is mandatory because of the potential risk of malignant degeneration. Appropriate treatment of acute appendicitis is debated: some surgeons suggest operative treatment, but others advocate for non-operative management. In our case the patient was submitted to surgery avoiding the risk of diagnostic delay of neoplasm.

Conclusion

Appendiceal tubulo-villous adenoma is a rare neoplasm difficult to diagnose and suspect because of lack of pathognomonic symptoms and specific diagnostic signs. Acute appendicitis is the most common clinical presentation. Appendectomy is the appropriate treatment.

Peritoneal Metastases from Appendiceal Cancer

The early symptoms of appendiceal cancer may mimic the clinical picture of appendicitis. Most patients are diagnosed incidentally during surgical exploration or late when peritoneal or systemic dissemination has already occurred, as colonoscopy rarely will diagnose an appendiceal cancer. Systemic/extraperitoneal metastases are distinctly unusual for appendiceal mucinous lesions.

The Role of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Appendiceal Tumors and Colorectal Adenocarcinomas

Peritoneal surface disease (PSD) has historically been used interchangeably with the term peritoneal carcinomatosis (PC) and has a dismal natural history. A variety of malignant pathologies, including colorectal and appendiceal primary tumors, can disseminate throughout the peritoneal cavity, leading to bowel obstruction and death. In general, peritoneal spread from high-grade appendiceal and colorectal primaries has the potential of hepatic and distant spread and best classified as PC. Low-grade appendiceal tumors are better categorized as PSD, due to low cellularity, high mucin production, and lack of potential spread outside the peritoneal cavity. Growing international experience with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) over the past 30 years has presented a therapeutic option to patients with PSD from colorectal and appendiceal tumors that can provide significant disease control, as well as potential for previously unattainable long-term survival. The proliferation of HIPEC centers and ongoing prospective trials are helping to standardize HIPEC techniques and patient selection.

Appendiceal Neoplasms

Appendiceal neoplasms are identified in 0.9 to 1.4% of appendiceal specimens, and the incidence is increasing. It has long been professed that neuroendocrine tumors (formerly carcinoids) are the most common neoplastic process of the appendix; recent data, however, has suggested a shift in epidemiology. Our intent is to distill the complex into an algorithm, and, in doing so, enable the surgeon to seamlessly maneuver through operative decisions, treatment strategies, and patient counseling. The algorithm for evaluation and treatment is complex, often starts from the nonspecific presenting complaint of appendicitis, and relies heavily on often subtle histopathologic differences.

A Multicenter Randomized Trial to Evaluate Hematologic Toxicities after Hyperthermic Intraperitoneal Chemotherapy with Oxaliplatin or Mitomycin in Patients with Appendiceal Tumors

BACKGROUND

Appendiceal cancer is a rare disease that has proven difficult to study in prospective trials. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is an established therapy for peritoneal dissemination from appendiceal cancer. The optimal chemotherapeutic agent to use in the HIPEC is not clear. Mitomycin has long been used, however, our previous phase I experience and European retrospective studies suggest oxaliplatin as an alternative. Therefore, we initiated a multicenter randomized trial to compare mitomycin with oxaliplatin HIPEC for appendiceal cancer.

STUDY DESIGN

Patients with mucinous appendiceal neoplasms with evidence of peritoneal dissemination underwent cytoreductive surgery and HIPEC using a closed technique for 120 minutes. Patients were randomized intraoperatively to HIPEC using mitomycin (40 mg) or oxaliplatin (200 mg/M²). Follow-up included daily blood counts and toxicity assessments.

RESULTS

One hundred and twenty-one analytic patients were accrued to the trial during 6 years at 3 sites. The patients were 57% female, with a mean age of 55.3 years (range 22 to 82 years). The disease was low grade in 77% and high grade in 23%. There were no significant differences in hemoglobin or platelet counts. The WBC was significantly lower in the mitomycin group between postoperative days 5 and 10. Overall and disease-free survival rates at 3 years were similar at 83.7% and 66.8% for mitomycin and 86.9% and 64.8% for oxaliplatin.

CONCLUSIONS

This represents the first completed prospective randomized trial for cancer of the appendix, and shows that multicenter trials for this disease are feasible. Both mitomycin and oxaliplatin are associated with minor hematologic toxicity. However, mitomycin has slightly higher hematologic toxicity and lower quality of life than oxaliplatin in HIPEC. Consequently, oxaliplatin might be preferred in patients with leukopenia and mitomycin preferred in patients with thrombocytopenia due to earlier chemotherapy.

Neoplasms of the Appendix: Pictorial Review with Clinical and Pathologic Correlation

Appendiceal neoplasms are uncommon tumors of the gastrointestinal tract that may manifest with symptoms of appendicitis, right lower quadrant pain, or palpable mass, leading to imaging or surgical intervention. The majority of appendiceal masses consist of primary epithelial neoplasms and neuroendocrine tumors (NETs). Epithelial neoplasms-mucinous and nonmucinous types-are more often detected at imaging than NETs due to their larger size and propensity for peritoneal spread and metastatic disease. Epithelial mucinous neoplasms are defined by the presence of mucin, detected at radiologic and pathologic examination. A mucocele or pseudomyxoma peritonei from epithelial mucinous tumors are the two most common cross-sectional imaging findings of appendiceal mucinous neoplasms. Nonmucinous epithelial tumors are less common and manifest as masses similar to colonic-type malignancies. NETs are often discovered incidentally at appendectomy due to their small size and nonaggressive behavior. Imaging findings of primary appendiceal tumors may overlap with those of acute appendicitis. Additionally, an appendiceal mass may cause acute appendicitis, obscuring the underlying mass. Other neoplasms including lymphoma, sarcoma, mesenchymal and nerve sheath tumors, or secondary malignant involvement of the appendix are rare. Treatment depends on the histologic subtype and extent of disease. Detailed description of organ, nodal, and peritoneal involvement informs surgical management with the goal of complete cytoreduction. Novel treatments such as hyperthermic intraperitoneal chemotherapy have increased survival for patients with mucinous tumors. ^©RSNA, 2017.

Limited, local, extracolonic spread of mucinous appendiceal adenocarcinoma after perforation with formation of a malignant appendix-to-sigmoid fistula: Case report and literature review

A 68-year-old man presented with progressive right lower quadrant abdominal pain and tenderness without rebound tenderness, and with constipation during the prior 9 mo. Abdomino-pelvic computed tomography and magnetic resonance imaging demonstrated a dilated appendix forming a fistula to the sigmoid colon. Open laparotomy revealed a bulky abdominal tumor involving appendix, cecum, and sigmoid, and extending up to adjacent viscera, without ascites or peritoneal implants. The abdominal mass was removed en bloc, including resection of sigmoid colon, cecum (with preservation of ileocecal valve), appendix, right vas deferens, testicular vessels, and minimal amounts of anterior abdominal wall; and shaving off of small parts of the walls of the urinary bladder and small bowel. Gross and microscopic pathologic examination revealed an appendix-to-sigmoid malignant fistula secondary to perforation of mucinous adenocarcinoma of the appendix with minimal local spread (stage T4). However, the surgical margins were clear, all 13 resected lymph nodes were cancer-free, and pseudomyxoma peritonei or peritoneal implants were not present. The patient did well during 1 year of follow-up with no clinical or radiologic evidence of local recurrence, metastases, or pseudomyxoma peritonei despite presenting with extensive stage T4 cancer that was debulked without administering chemotherapy, and despite presenting with malignant appendiceal perforation. This case illustrates the non-aggressive biologic behavior of this low-grade malignancy. The fistula may have prevented free spillage of cancerous cells and consequent distant metastases by containing the appendiceal contents largely within the colon.

Prognostic Molecular Subtypes of Low-Grade Cancer of the Appendix

BACKGROUND

Appendiceal cancer (AC) patients treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) often demonstrate an unpredictable variability in their survival outcomes. Biomarkers predictive of CRS/HIPEC efficacy could better guide treatment decisions. We hypothesized that variation in the transcriptional programming of AC tumors might distinguish molecular subtypes with differential outcomes after CRS/HIPEC.

STUDY DESIGN

Gene expression profiles of 2 AC cohorts were analyzed using Affymetrix whole-genome expression microarrays. Hierarchical clustering methods, Kaplan-Meier analysis, and Cox regression models were used to discover and validate prognostic molecular subtypes of AC. Gene set enrichment analysis was used to infer pathologic attributes of the molecular subtypes.

RESULTS

Unsupervised hierarchical clustering analysis of tumor expression profiles revealed a 139-gene cassette that distinguished 2 molecular subtypes (based on low vs high expression of the gene cassette) with statistically significant survival differences (disease-specific survival, p = 0.0075; progression-free survival, p = 0.0072). In a second AC cohort, the 139-gene cassette reproducibly partitioned tumors into subtypes with significant survival differences. Tumors showing high relative expression of the genes comprising the cassette associated with poor survival outcomes (disease-specific survival, p = 0.047; progression-free survival, p = 0.0079), and exhibited gene expression patterns enriched for oncogenic processes and pathways. The prognostic value of the molecular subtypes was specific for low-grade appendiceal tumors (disease-specific survival, p = 0.028; progression-free survival, p = 0.0016), and remained significant in the presence of conventional prognostic markers, including grade, surgical resection score, Eastern Cooperative Oncology Group status, and age.

CONCLUSIONS

The 139-gene cassette can have actionable clinical utility for identifying low-grade appendiceal tumor molecular subtypes predictive of therapeutic efficacy of CRS/HIPEC.

Persistent Coughing as the First Symptom of Primary Mucinous Appendiceal Adenocarcinoma

Primary appendiceal adenocarcinomas are extremely rare entities. Preoperative diagnosis is very difficult and is mainly based on computed tomography (CT) scan findings. Furthermore, in many cases, difficulties in establishing an accurate intraoperative diagnosis have resulted in a two-stage surgical intervention. We herein report a case of a primary appendiceal mucinous adenocarcinoma in a 67-year-old Caucasian man who presented with atypical symptoms of persistent coughing and weight loss. The chest CT showed lesions with features favorable of malignancy. Further investigation with abdominal CT and colonoscopy revealed a large tumor of the cecum expanding to the ascending colon. Typical right hemicolectomy was performed and the histopathological examination confirmed mucinous adenocarcinoma of the appendix. As some cases are accidentally discovered, the presented case describes an extremely rare first presentation of this tumor and emphasizes that the preoperative diagnosis of appendiceal cancer is challenging due to the lack of specific symptoms and signs.

Intramucosal carcinoma of the appendix arising from traditional serrated adenoma

Introduction. Serrated adenomas of the appendix are rare and usually found during appendectomy or autopsies. The preoperative diagnosis of these tumors is uncommon. This report describes a case of a sessile serrated adenoma located in the appendix diagnosed by a screening colonoscopy and successfully treated by laparoscopic removal. Presentation of Case. An 86-year-old woman underwent colonoscopy to investigate the cause of her diarrhea, weight loss, and anemia. During the colonoscopy, an expansive and vegetating mass of 1.5 cm in diameter was identified, protruding through the appendicular ostium with slightly lateral growth to the cecum. The patient was referred for laparoscopic surgical resection due to the location of the lesion, which did not allow its removal by colonoscopy. She underwent wedge removal of the cecum without complications and was discharged on the 4th postoperative day. Histopathological examination showed the presence of a sessile serrated adenoma with an intramucosal adenocarcinoma. The patient is currently well one year after surgery, without endoscopic signs of relapse. Conclusion. Despite serrated adenomas being a possibility rarely described in appendix it should be recognized and properly treated because it is presenting a higher risk of cancer.

The rise in appendiceal cancer incidence: 2000-2009

PURPOSE

Appendiceal cancer is a rare and potentially aggressive malignancy. The objectives of this study were to characterize secular demographic patterns of disease and to determine survival by using a population-based data source.

METHODS

Using the Surveillance, Epidemiology, and End Results database, we conducted a retrospective cohort analysis of patients treated from 2000-2009.

RESULTS

We identified 4765 patients with appendiceal cancer. The incidence of appendiceal cancer increased by 54% from 2000 (0.63 per 100,000) to 2009 (0.97 per 100,000 population). Incidence rates increased across all tumor types, stages, age groups, and gender. The most common malignancies were mucinous adenocarcinoma (38%), followed by carcinoids (28%), adenocarcinoma-not otherwise specified (NOS) (27%), and signet ring cell adenocarcinoma (7%). Larger tumor size and older patient age were significantly associated with higher relative odds of distant disease at diagnosis (P < 0.0001). Patient and demographic characteristics were significantly associated with higher relative hazard of death (P < 0.0001).

CONCLUSIONS

Although appendiceal cancer is rare, the incidence increased significantly in the USA from 2000 to 2009. The cause of this trend is not obvious. We did not observe increases differentially associated with stage, histology, or demographic characteristics. Further investigation is needed to examine factors underlying this increase.

The incidence of mucinous appendiceal malignancies: a population-based study

PURPOSE

Mucinous appendiceal tumours were described already 180 years ago, but reliable data on the incidence of these tumours are sparse. The clinical importance of these tumours is increasing since they are now identified as the most common site of origin for pseudomyxoma peritonei (PMP), which is currently recognised as a treatable condition.

METHODS

Data on the incidence of mucinous appendiceal tumours were retrieved from the Eindhoven Cancer Registry, which collects data on all patients with newly diagnosed cancer in a large part of the southern Netherlands that comprises about 2.3 million inhabitants. From 1980 to 2010, all cases of primary adenocarcinomas of the appendix were included.

RESULTS

From 1980 to 2010, a mucinous adenocarcinoma was diagnosed in 78 patients being 48 % of all cases of appendiceal adenocarcinoma diagnosed during this period (n = 164). The incidence increased during the study period from 0.6 to 1.9 per 1,000,000 person-years for women and from 0.4 to 1.0 per 1,000,000 person-years for men.

CONCLUSION

The reported incidence of mucinous adenocarcinomas of the appendix shows an increasing trend. This is probably mainly explained by the increased awareness of this tumour and its relation with PMP, and better registration of this specific diagnosis.

Mucinous adenocarcinona of the appendix

Diagnosis of malignancy in the vermiform appendix is quite rare. The most common histological malignant neoplasia found in this tiny portion of the gastrointestinal tract is represented by the mucinous adenocarcinoma. This entity predominates in males around 50 years of age, and clinical presentation usually mimics or occurs along with an acute appendicitis. Early diagnosis is outside the rule since most cases at this stage are symptomless. The authors present the case of a 59-year-old female patient who looked for medical attention complaining of abdominal pain. Physical examination and laboratory workup were poor in diagnostic findings. The computed tomography images were compatible with the diagnosis of appendicitis and/or appendiceal neoplasia. The patient underwent a laparotomy and right hemicolectomy. The histological examination disclosed a moderately differentiated mucinous adenocarcinoma of the appendix stage T4a, N0, M0. The patient outcome was uneventful and was referred to an oncological center.

Incidentally Discovered Adenocarcinoma in situ of the Appendix in a Young Woman

Primary appendiceal adenocarcinoma is an infrequent disease. This report presents a rare case of incidentally discovered carcinoma in situ of the appendix. A 35-year-old parturient female simultaneously underwent appendectomy and oophorectomy due to an ovarian abscess that adhered to the appendix during cesarean section. Although her excised appendix showed no apparent tumorous lesion, histopathological examination revealed carcinoma in situ in the excised appendix. She underwent additional right hemicolectomy a few days later due to the possibility of a positive surgical margin. Histopathological examination detected no malignant cells in the resected specimen. She was discharged without any complications and has since remained healthy. Appendiceal adenocarcinoma is generally considered to be difficult to diagnose during the early stage because it seldom shows any specific findings. This results in a poor prognosis. Histopathological examination is not always conducted for appendices resected during other surgery. However, the current study suggests that a careful routine histopathological examination of excised appendix, as well as careful preoperative examination and detailed intraperitoneal inspection during surgery, is indeed important to detect occult appendiceal tumors.

Cerebral metastasis from a previously undiagnosed appendiceal adenocarcinoma

Brain metastases arise in 10%–40% of all cancer patients. Up to one third of the patients do not have previous cancer history. We report a case of a 67-years-old male patient who presented with confusion, tremor, and apraxia. A brain MRI revealed an isolated right temporal lobe lesion. A thorax-abdomen-pelvis CT scan showed no primary lesion. The patient underwent a craniotomy with gross-total resection. Histopathology revealed an intestinal-type adenocarcinoma. A colonoscopy found no primary lesion, but a PET-CT scan showed elevated FDG uptake in the appendiceal nodule. A right hemicolectomy was performed, and the specimen showed a moderately differentiated mucinous appendiceal adenocarcinoma. Whole brain radiotherapy was administrated. A subsequent thorax-abdomen CT scan revealed multiple lung and hepatic metastasis. Seven months later, the patient died of disease progression. In cases of undiagnosed primary lesions, patients present in better general condition, but overall survival does not change. Eventual identification of the primary tumor does not affect survival. PET/CT might be a helpful tool in detecting lesions of the appendiceal region. To the best of our knowledge, such a case was never reported in the literature, and an appendiceal malignancy should be suspected in patients with brain metastasis from an undiagnosed primary tumor.

Periappendiceal abscess mimicking appendiceal cancer

Appendiceal cancer was strongly suspected in this case because of its unique colonoscopic, radiologic, and intraoperative presentation. Hence, laparoscopic enbloc right hemicolectomy and peritonectomy were performed. The diagnosis of periappendiceal abscess was confirmed later after the operation. Appendiceal disease is hard to differentiate because of the wide spectrum of differential diagnosis. So, when there is a strong suspicion of appendiceal cancer, laparoscopic right colectomy, which is minimally invasive and potentially curative can be the treatment of choice.