Appendiceal Adenocarcinoma Research Articles

Trends in the Incidence, Prevalence, and Survival Outcomes of Appendiceal Adenocarcinoma

Background: Appendiceal carcinoma is a rare malignant tumor with aggressive potentials. Appendiceal adenocarcinoma (AA) accounts for approximately two thirds of it. Aim: This study aimed to explore the epidemiologic changes of AA and reveal the possible influences of therapeutic advances on survival of patients with AA. Methods: We retrospectively identified 6066 patients with AA treated between 2000 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) program. Pertinent data were analyzed for incidence and prevalence. Survival analysis was made by the actuarial or Kaplan-Meier and compared by log-rank test. Cox proportional hazards model was adopted for prognostic variable evaluation. Results: We identified 6066 cases with AA. Its annual age-adjusted incidence was 0.47 per 100,000 in 2000 and increased to 1.11 per 100,000 by 2014. The incidence increased the steepest in patients under 50 years old, with a threefold escalation to 0.60 per 100,000 in 2014. The elevation of the incidence was noted in all the histologic types, stages and grades. The 20-year limited-duration prevalence of AA was 6 per 100,000 on January 1, 2014. The multivariable analysis showed the median survival time was statistically different in gender, year of diagnosis, grade, stage, type of surgery performed and histologic subtype. The median survival time was prolonged from 2000-2006 to 2007-2014 (hazard ratio (HR) 0.87; 95% CI, 0.80-0.94). Conclusion: These results showed an elevation in the incidence, prevalence of AA, which may be interpreted by the advancement of examining techniques. The improvement in survival may result from the development of therapies. Furthermore, these results suggested clinicians pay more attention to AA and indicated some potential research directions.

Mucinous Adenocarcinoma of the Appendix: A Deep-Seated Tumor

Primary tumors of the appendix are rare and approximately 85% are carcinoids. Primary adenocarcinoma of the appendix accounts for about 0.2% of all gastrointestinal neoplasms, only 6% of appendiceal cancers, 0.05%-0.2% of all appendectomy specimens, and have an age-adjusted incidence of 0.12 cases per 1,000,000 patients per year. Appendiceal adenocarcinoma is categorized into colonic, mucinous, goblet cell, and signet ring cell subtypes. We present a 72-year-old male with a past medical history of diabetes mellitus and benign prostatic hyperplasia with complaints of abdominal pain for two days. The pain was located in the left upper and lower quadrants, characterized as spastic and lasting for a few minutes at a time. An abdominal computed tomography (CT) scan showed severe loss of serosal margins about the cecum extending posteriorly through the peritoneal lining of the right paracolic gutter. A mass with a diameter of 3.8 x 3.3 cm was identified along the base of the cecum extending cephalic to the inferior edge of the ileocecal junction. The appendix was not identifiable. Diagnostic colonoscopy failed to identify any cecal mass and the appendiceal orifice appeared normal. Biopsies from the cecum were unremarkable. The patient was referred for surgical consultation with subsequent exploratory laparoscopy identifying a large hard fixed appendiceal mass measuring 5.5 x 3.5 x 3.5 cm. The mass was resected and a right hemicolectomy with side-to-side anastomosis performed. Surgical pathology revealed moderately differentiated mucinous adenocarcinoma of the appendix extending to the cecal subserosal fat; TNM staging T3N0M0, Grade 2, Stage IIa. Mucinous adenocarcinoma (MA) usually presents with nonspecific findings. Abdominal pain is the most frequently cited symptom, resembling acute appendicitis. However, MA can present as an abdominal mass detected by palpation or abdominal imaging, and rarely with nausea, vomiting, ascites, or unintentional weight loss. As a result of its nonspecific presentation, it is rarely diagnosed preoperatively. Furthermore, appendiceal cancers are commonly missed during colonoscopy as the cancer is located deep in the appendix and not visible from the cecal lumen. These tumors are found during exploratory surgery, similar to our case. Although rare, appendiceal tumors should be part of the differential diagnosis when a history of abdominal pain and a cecal or appendiceal mass is seen on CT scan despite a negative colonoscopy.1467 Figure 1. (Above) Abdominal computed tomography (CT) scan showed severe loss of serosal margins about the cecum, extending posteriorly through the peritoneal lining of the right paracolic gutter. A mass was identified along the base of the cecum, with a diameter of 3.8 x 3.3 cm, extending cephalic to the inferior edge of the ileocecal junction. The appendix was not identifiable as a discrete structure. (Below) Diagnostic colonoscopy was unable to identify any intestinal masses extending into the lumen.

Primary adenocarcinoma of the appendix in a child: A case report

BackgroundPrimary adenocarcinoma of the appendix is a rare disease in clinical practice. Moreover, primary adenocarcinoma of the appendix in the pediatric age group is even rarer with very little cases being published. Here, we report a case of primary adenocarcinoma of the appendix with local invasion into adjacent organs in a child who was initially diagnosed as having an acute appendicitis.Case presentationA 13-year-old girl presented with abdominal pain of 3-month duration. Imaging study showed a mass including the fecalith that occupied her pelvic and right lower abdominal cavity. Drainage of the abscess and appendectomy were performed by the preoperative diagnosis of an acute appendicitis with an appendiceal mass. Postoperative histopathological examinations revealed the appendiceal adenocarcinoma. She then received the whole mass resection, ileocecal resection with lymph node dissection. The masses were tightly adherent with infiltration into the sigmoid colon, uterus, and right ovary. These organs were all dissected, and subsequent sigmoid colostomy was performed. We preserved the left ovary for her fertility. The pathological findings demonstrated negative margins and no lymph node invasions, and final pathological stage was pT4(SI)N0M0, stage II. After the operation, she received the chemotherapy with 6 cycles of 5-fluorouracil (5-FU), leucovorin (LV), and oxaliplatin (mFOLFOX6) and subsequent 6 cycles of simplified LV and 5-FU (sLV5FU2). The patient is doing well till today on follow-up without progression of the disease 5 years after the operation.ConclusionPrimary adenocarcinoma of the appendix is exceedingly rare in children. In this report, we described one of the youngest primary adenocarcinomas of an appendix case ever reported. When encountering atypical cases of the appendicitis, we should consider the possibility of primary adenocarcinoma of the appendix as it has an extremely poor prognosis and is usually diagnosed in advanced stages.

Biological mesh is a safe and effective method of abdominal wall reconstruction in cytoreductive surgery for peritoneal malignancy.

BackgroundPatients with peritoneal malignancy often have multiple laparotomies before referral for cytoreductive surgery (CRS). Some have substantial abdominal wall herniation and tumour infiltration of abdominal incisions. CRS involves complete macroscopic tumour removal and hyperthermic intraperitoneal chemotherapy (HIPEC). Abdominal wall reconstruction is problematic in these patients. The aim of this study was to establish immediate and long‐term outcomes of abdominal wall reconstruction with biological mesh in a single centre.MethodsA dedicated peritoneal malignancy database was searched for all patients who had biological mesh abdominal wall reconstruction between 2004 and 2015. Short‐ and long‐term outcomes were reviewed. All patients had annual abdominal CT as routine peritoneal malignancy follow‐up.ResultsSome 33 patients (22 women) with a mean age of 53·4 (range 19–82) years underwent abdominal wall reconstruction with biological mesh. The majority (23) had CRS for pseudomyxoma (19 low grade), six for colorectal peritoneal metastasis and four for appendiceal adenocarcinoma; 18 had undergone CRS and HIPEC previously. Twenty‐five of the 33 patients had abdominal wall tumour involvement and eight had concurrent hernias. The mean duration of surgery was 486 (range 120–795) min and the mean mesh size used was 345 (50–654) cm2. Ten patients developed wound infections and four had a seroma. Two developed early enterocutaneous fistulas. Mean follow‐up was 48 months. Five patients developed an incisional hernia. Four died from progressive malignancy. A further 15 patients had disease recurrence, but only one had isolated abdominal wall recurrence.ConclusionBiological mesh was safe and effective for abdominal wall reconstruction in peritoneal malignancy. Postoperative wound infections were frequent but nevertheless incisional hernia rates were low with no instances of mesh‐related bowel erosion or fistulation.

Analysis of Appendiceal Neoplasms on 3544 Appendectomy Specimens for Acute Appendicitis: Retrospective Cohort Study of a Single Institution.

BackgroundAppendiceal neoplasms are rare and generally determined in appendectomy specimens for acute appendicitis. Depending on a tumor’s histopathology and size, appendectomy or right hemicolectomy are the surgical treatment options. Adenocarcinomas, mucinous neoplasms, goblet cell carcinoids and neuroendocrine tumors are the types of the primary appendiceal neoplasm histopathology. In this study, we aimed to determine the incidence of appendiceal neoplasms in an acute appendicitis cohort. Also, histopathological distributions, demographic data, preoperative radiological diagnosis, and intraoperative findings were revealed for analysis, retrospectively.Material/MethodsBetween October 2011 and September 2017, 3554 appendectomies were performed for acute appendicitis in Bezmialem University Hospital, Istanbul Turkey. The medical records of these consecutive 3554 patients were evaluated retrospectively. After the histopathological analysis of the appendectomy specimens, a total of 28 patients were detected as having appendiceal neoplasm including appendiceal adenocarcinoma, low grade mucinous neoplasia, and appendiceal neuroendocrine tumors.ResultsAppendiceal neoplasms were determined in 28 out of 3554 acute appendicitis patients with an incidence of 0.78%. According to the histopathological types, 3 of the cases (10.7%) were appendiceal adenocarcinoma, 8 of the cases (28.5%) were low grade mucinous neoplasia, and 17 of the cases (60.8%) were neuroendocrine tumors. The overall incidence of the appendiceal neuroendocrine tumors was 0.48%.ConclusionsThe information obtained from our study suggests that pathological examination of the specimen may not be necessary if there is no doubt according to preoperative radiological diagnosis and/or intraoperative findings of the surgeon.

Molecular characterization of appendiceal cancer and comparison with right-sided (R-CRC) and left-sided colorectal cancer (L-CRC).

3611Background: The natural history and prognosis of appendiceal adenocarcinomas (AA) differ from that of adenocarcinomas arising in other large bowel sites. Compared to CRC, AA has more peritoneal...

Impact of adjuvant chemotherapy in appendiceal adenocarcinoma.

e16193Background: The impact of using adjuvant chemotherapy following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with appendiceal adenocarcinoma i...

Appendiceal goblet cell carcinoids and adenocarcinomas ex-goblet cell carcinoid are genetically distinct from primary colorectal-type adenocarcinoma of the appendix

AbstractThe appendix gives rise to goblet cell carcinoids, which represent special carcinomas with distinct biological and histological features. Their genetic background and molecular relationship to colorectal adenocarcinoma is largely unknown. We therefore performed a next-generation sequencing analysis of 25 appendiceal carcinomas including 11 goblet cell carcinoids, 7 adenocarcinomas ex-goblet cell carcinoid, and 7 primary colorectal-type adenocarcinomas, using a modified Colorectal Cancer specific Panel comprising 32 genes linked to colorectal and neuroendocrine tumorigenesis. The mutational profiles of these neoplasms were compared with those of conventional adenocarcinomas, mixed adenoneuroendocrine carcinomas, and neuroendocrine carcinomas of the colorectum. In addition, a large-scale pan-cancer sequencing panel covering 409 genes was applied to selected cases of goblet cell carcinoid/adenocarcinoma ex-goblet cell carcinoid (n=2, respectively). Mutations in colorectal cancer-related genes (eg, TP53, KRAS, APC) were rare to absent in both, goblet cell carcinoids and adenocarcinomas ex-goblet cell carcinoid, but frequent in primary colorectal-type adenocarcinomas of the appendix. Additional large-scale sequencing of selected goblet cell carcinoids and adenocarcinomas ex-goblet cell carcinoid revealed mutations in Wnt-signaling-associated genes (USP9X, NOTCH1, CTNNA1, CTNNB1, TRRAP). These data suggest that appendiceal goblet cell carcinoids and adenocarcinomas ex-goblet cell carcinoid constitute a morphomolecular entity, histologically and genetically distinct from appendiceal colorectal-type adenocarcinomas and its colorectal counterparts. Altered Wnt-signaling associated genes, apart from APC, may act as potential drivers of these neoplasms. The absence of KRAS/NRAS mutations might render some of these tumors eligible for anti-EGFR directed therapy regimens.

Appendiceal carcinoma associated with microsatellite instability.

Approximately 15% of colorectal cancer (CRC) cases exhibit microsatellite instability (MSI), which appears to be associated with unique biological behavior. The present study presents a case of appendiceal carcinoma associated with MSI that responded well to adjuvant chemotherapy. Clinical, pathological and immunohistochemical (IHC) characteristics have been described. The 60-year-old male patient had suffered from recurrent lower abdominal pain associated with abdominal distention for 6 months; then, following an acute attack, he was subjected to laparoscopic appendectomy. The histopathological examination revealed moderately differentiated appendiceal adenocarcinoma with mucinous areas, without lymphovascular or perineural invasion. The IHC examination was positive for keratin-20 and caudal type homeobox 2, and negative for MutL Homolog 1, MutS Homolog (MSH) 2 and MSH-6. A postoperative colonoscopy revealed diverticulosis, without the presence of polyps or tumors. However, an abdominal axial computerized tomography scan revealed thickening of the distal portion of the appendix, increased density of the greater omentum, and metastases to the liver capsule, spleen and peritoneum. The treatment of choice was right hemicolectomy with peritoneal debulking, followed by 10 cycles of chemotherapy with 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX regimen). After 5 years of follow-up, the patient remains in good condition, without clinical or radiological signs of recurrence. The good response to chemotherapy corresponds with the observations made in other colon cancers with MSI. Therefore, testing for MSI in appendiceal carcinomas may provide useful information on prognosis and predict response to chemotherapy.

MR Imaging of Secondary Massive Ovarian Edema Caused by Ovarian Metastasis from Appendiceal Adenocarcinoma.

MR Imaging of Secondary Massive Ovarian Edema Caused by Ovarian Metastasis from Appendiceal Adenocarcinoma.

Nationwide overview of survival and management of appendiceal tumors in children

IntroductionThere remains a paucity of literature on survival related to pediatric appendiceal tumors. The purpose of this study was to determine the incidence, surgical management, and survival outcomes of appendiceal tumors in pediatric patients. MethodsThe Surveillance, Epidemiology, and End Results (SEER) Registry was analyzed for pediatric appendiceal tumors from 1973 to 2011. Parameters analyzed were: tumor type, surgical management (appendectomy vs. extensive resection), tumor size, and lymph node sampling. Chi-square analysis for categorical and Student's t test for continuous data were used. ResultsOverall, 209 patients had an appendiceal tumor, including carcinoid (72%), appendiceal adenocarcinoma (16%), and lymphoma (12%). Patients undergoing appendectomy vs. extensive resection had similar 15-year survival rates (98% vs. 97%; p=0.875). Appendectomy vs. extensive resection conferred no 15-year survival advantage when patients were stratified by tumor type, including adenocarcinoma (87% vs. 89%; p=0.791), carcinoid (100% vs. 100%; p=0.863), and lymphoma (94% vs. 100%; p=0.639). There was no significant difference in 15-year survival between tumor size groups ≥2 and <2cm (both 100%) and presence or absence of lymph node sampling (96% and 97%; p=0.833) for all patients with a carcinoid tumor. ConclusionAppendectomy may be adequate for pediatric appendiceal tumors. Extensive resection may be of limited utility for optimizing patient survival, placing patient at greater operative risk. Type of StudyRetrospective Prognostic Study. Level of EvidenceIII

Development of Bone Metastasis Secondary to Appendiceal Adenocarcinoma with Signet Ring Cells

Development of Bone Metastasis Secondary to Appendiceal Adenocarcinoma with Signet Ring Cells

Interplay of grade and stage on survival outcomes in appendiceal adenocarcinoma: Corroboration of the AJCC (8th edition) Cancer Staging Classification.

773 Background: Histological grade is a key prognostic factor in appendiceal adenocarcinomas (AAs) and has been incorporated in classification of stage IV AAs (IVA – Grade 1: Well; IVB – Grade 2/3: Moderately/Poorly differentiated) in AJCC Cancer Staging (8th edition). The purpose of the study was to corroborate the prognostic impact of this staging classifier. Methods: We performed a retrospective review of 98 AA patients (pts) at UTMDACC (2013 - 2017). Kaplan-Meier method was used to estimate median overall survival (mOS), compared with log-rank tests with emphasis on stage and grade. Results: The cohort included 18, 8, 14, 47 and 11 cases of stage II, III, IVA, IVB and IVC AAs. Histologically, 75 were mucinous (21 non mucinous) and 19, 35 and 42 were grade 1, 2 and 3 respectively. Median age of cohort was 54 years. Median follow-up was 46 months (m). The mOS of stage II, III, IVA, IVB and IVC was 136, 106, 140, 48, 23 m, respectively (P &lt; 0.0001). The mOS of grade 1, 2 and 3 was 160, 75 and 33 m, respectively (P &lt; 0.0001). In univariate analysis (restricted to stage IV pts), grade, AJCC stage, and cytoreductive surgery (CRS) were found to be associated with OS. In multivariate analyses (restricted to stage IV pts), only AJCC stage (HR 3.9, 95% CI: 1.5 - 10.6, P = 0.005) and CRS (HR 3.4, 95% CI: 1.4 – 8.3, P = 0.009) were found to be independently associated with poor OS. In subgroup of mucinous AAs, mOS of grade 3 (32 m) was significantly shorter than grade 2 (54 m) (P = 0.02). In non-mucinous AAs, mOS of grade 3 and grade 2 pts was 38 and 29 m, respectively (P = 0.97). Conclusions: AJCC staging classification has a strong prognostic value in AAs. Beyond the well differentiated AAs which are regarded as a distinct entity in stage IV disease, moderate and poor differentiation also has strong and dissimilar prognostic impact which appears to be dependent on mucinous or non-mucinous subtype in stage IV AAs. Further efforts are needed to incorporate the complex interplay of all grades and mucinous characteristics within the staging system for better prognostication and management.

Comprehensive genomic profiling of appendiceal adenocarcinoma.

298 Background: Appendiceal adenocarcinomas (AAs) are orphan tumors. Little is known about their molecular profile limiting understanding of their biology and development of novel targeted therapies. The purpose of this study was to delineate the molecular landscape of AAs. Methods: We performed a retrospective review of AAs patients (pts) who were evaluated at MD Anderson Cancer Center between October 2012 and April 2017 and underwent next-generation sequencing (NGS) with internal or external assays (at least 45 genes) using either tumor tissue specimens or peripheral blood for circulating cell-free DNA (cfDNA). The primary outcome was to assess the prevalence of genomic alterations (GAs) in AAs. We then performed comparative exploratory analyses of GAs using TCGA colorectal cancer (CRC) sequencing. Results: A total of 78 patients were identified of which 57 (73%) and 18 (23%) underwent tissue based and ctDNA based sequencing, respectively (3 cases had both). At least 1 GA was found in 61 (78%) of AA specimens, with a mean (SD) of 2.8 (1.6) GAs per case. Of these 44 (72%) had ≥ 2 GAs and 31 (51%) had ≥ 3 GAs. The most frequent GAs were KRAS (38 [62%]), TP53 (22 [36%]), GNAS (17 [28%]), SMAD4 (11 [18%]), PIK3CA (10 [16%]), APC (9 [15%]), ATM (8 [13%]), BRAF (5 [8%]), KIT (5 [8%]), NRAS (3 [5%]) and MET (3 [5%]). GNAS mutations frequently co-occurred with KRAS mutations (42% v 5%, OR 14.3, P &lt; 0.001). No GA was associated with grade, mucinous histology or overall survival (OS). Besides these mutations, we also found unusual cases with targetable mutations such as ALK, EGFR, MET, IDH1 and ERBB2. In our comparative analyses, mutations in KRAS (p = 0.009), TP53 (p = 0.020), GNAS (p &lt; 0.001) and APC (p &lt; 0.001) genes were significantly different from CRC whereas there was no difference in prevalence of PIK3CA, SMAD4 and ATM genes. Conclusions: To date, our analysis of one of the largest cohorts of AAs, demonstrate a majority of AAs harbor at least 1 GAs. Although treatment paradigms in AAs are extrapolated from CRC, the molecular profile of these tumors differs significantly. Molecular characterization of these rare tumors is a necessary first step towards discovery of opportunities for use of targeted therapies in these patients.

Somatic mutation landscape of appendiceal cancer.

671 Background: Appendiceal cancers are rare, comprising just 0.5% of all intestinal neoplasia, which has prevented the systematic study of these tumors in randomized clinical trials. Given this absence of clinical data, no evidence-based guidelines exist regarding the best management of this disease. Standard treatment generally follows consensus guidelines for colorectal cancer; however, there are currently no standards to guide chemotherapy selection in the adjuvant or metastatic setting. Methods: Somatic mutation profiles covering ~300 frequently mutated genes were obtained for 385 primary appendiceal tumors (Foundation Medicine). A retrospective review was performed to gather clinico-pathologic data. The primary objective was to assess the somatic mutation profile of each subtype of appendiceal cancer and to compare these to colorectal cancer. Colorectal data was obtained from TCGA cohort via cBioPortal. Results: Appendiceal adenocarcinoma (non-mucinous) and mucinous adenocarcinoma had shared somatic mutations albeit with differing frequencies. The most common mutations were KRAS (60.1% and 80.5%, respectively), GNAS (32.4%, 58.5%), TP53 (42.8%, 19.5%), and SMAD4 (14.8%, 14.6%). Tumors with goblet cell (adenocarcinoid) histology had lower prevalence of KRAS (16.0%) and GNAS mutations (8.0%), but similar prevalence of TP53 mutation (24.0%) and a greater prevalence of ARID1A mutation (20.0%). The mutation profiles of all appendiceal histologies differed from colorectal adenocarcinoma with markedly lower prevalence of ATM (7.9% vs. 71.0%). Chemotherapy data was available for 30 metastatic patients; these patients received an average of 1.76 lines of therapy (range 1-4). All 30 were treated with either 5-FU or capecitabine, 11 (36.7%) with oxaliplatin, 23 (76.7%) with irinotecan and 19 (63.3%) with bevacizumab. Analysis of survival data and correlation with molecular and histologic features is ongoing. Conclusions: Despite clear molecular differences between appendiceal and colorectal tumors, appendiceal tumors are primarily treated with colorectal chemotherapy regimens. There remains a pressing need for both pre-clinical and clinical investigation to develop treatment regimens specific to appendix cancer.

Mucinous Neoplasm of the Appendix and Pseudomyxoma Peritonei

This image shows a mucinous neoplasm replacing the appendix, extending through the wall of the appendix, causing mucin accumulation in the peritoneum with extensive involvement of the serosa and omentum. Which of the following statements is true about appendiceal tumors?a.Appendiceal mucinous tumors are the only tumors associated with pseudomyxoma peritoneib.Pseudomyxoma peritonei may be caused by mucinous tumors of various sites, including the appendix, ovary, colon, pancreas, and gallbladder, but appendiceal tumors are the most common causec.Well-differentiated neuroendocrine tumors (carcinoid tumors) are the most aggressive tumors of the appendixd.Pseudomyxoma peritonei occurs only with high-grade tumors Answer: b. Pseudomyxoma peritonei may be caused by mucinous tumors of various sites, including the appendix, ovary, colon, pancreas, and gallbladder, but appendiceal tumors are the most common cause Mucinous tumors of various sites, including the appendix, ovary, colon, pancreas, and gallbladder, have been associated with pseudomyxoma peritonei. But the most common cause of pseudomyxoma peritonei is peritoneal spread of a mucinous appendiceal neoplasm. The term “pseudomyxoma peritonei” is a clinical term used to describe the accumulation of extensive mucin in the peritoneal cavity.1Carr N.J. Bibeau F. Bradley R.F. et al.The histopathological classification, diagnosis and differential diagnosis of mucinous appendiceal neoplasms, appendiceal adenocarcinomas and pseudomyxoma peritonei.Histopathology. 2017; 71: 847-858Crossref PubMed Scopus (122) Google Scholar

SATB2 Shows Different Profiles Between Appendiceal Adenocarcinomas Ex Goblet Cell Carcinoids and Appendiceal/Colorectal Conventional Adenocarcinomas: An Immunohistochemical Study With Comparison to CDX2.

BackgroundSpecial AT-rich sequence-binding protein 2 (SATB2) is a novel marker for colorectal adenocarcinomas but little is known about its expression in appendiceal adenocarcinomas. We aim to investigate SATB2 in these tumors and colorectal adenocarcinomas with comparison to CDX2.MethodsImmunohistochemical stains for SATB2 and CDX2 were performed in 49 appendiceal adenocarcinomas (23 conventional, 26 adenocarcinoma ex goblet cell carcinoids (AdexGCCs)) and 57 colorectal adenocarcinomas. Their expression was correlated with tumor differentiation and growth patterns.ResultsSATB2 staining was positive in 26/26 (100%) appendiceal AdexGCCs and 15/23 (65%) appendiceal conventional adenocarcinomas (P = 0.001). Their mean percentage of SATB2-positive cells was 93% and 34%, respectively (P < 0.0001). CDX2 staining was seen in 26/26 (100%) AdexGCCs and 22/23 (96%) appendiceal conventional adenocarcinomas (P = 0.4694). SATB2 and CDX2 showed similar staining in AdexGCCs but CDX2 labeled more tumor cells than SATB2 in conventional adenocarcinomas (mean 84% vs. 34%, P < 0.0001). SATB2 and CDX2 staining was seen in 82% (47/57) and 96% (55/57) colorectal adenocarcinomas, respectively (P = 0.01). The mean percentage of cells positive for SATB2 and CDX2 was 48% and 91%, respectively (P < 0.00001). Decreased SATB2 immunoreactivity was associated with non-glandular differentiation particularly signet ring cells in colorectal (P = 0.001) and appendiceal conventional adenocarcinomas (P = 0.04) but not in appendiceal AdexGCCs.ConclusionsSATB2 is a highly sensitive marker for appendiceal AdexGCCs with similar sensitivity as CDX2. In colorectal and appendiceal conventional adenocarcinomas, SATB2 is not as sensitive as CDX2 and its immunoreactivity is dependent on tumor differentiation.

Adenocarcinoma of the appendix mimicking complicated appendicitis in the elderly: A report of two cases

Introduction. Primary appendiceal adenocarcinoma is a very rare malignancy which accounts for 0.1% of all appendectomy specimens. In both patients presented in this paper, appendectomy was performed due to suspected acute complicated appendicitis. Case Reports. The first patient, a 77-year-old man, presented with a low grade colonic-type pT3 adenocarcinoma of the appendix, diagnosed by histopathological examination of the resected appendix delivered in a fixative. A month after appendectomy, the patient underwent right hemicolectomy of a tumor at the edge of the resection. Due to a cardiovascular disease, adjuvant chemotherapy was not indicated. The second patient, a 74-year-old female, presented with a low grade mucinous adenocarcinoma of the appendix with subserous infiltration, diagnosed by histopathological analysis of the resected appendix. Eight months after appendectomy, the patient developed a recurrent tumor in the cecal area. After radical surgical excision of the recurrent tumor, the patient received adjuvant chemotherapy. Both patients had a 5-year survival without relapse. Conclusion. Preoperative diagnosis of appendiceal adenocarcinoma is a challenge due to overlapping symptoms of complicated acute appendicitis. Our results suggest that in elderly patients with symptoms of complicated acute appendicitis, appendectomy should be done with intraoperative histopathological frozen section consultation. In advanced stages of adenocarcinoma, right hemicolectomy is a better choice than appendectomy.

A rare case of locally advanced mucinous adenocarcinoma of the appendix confined in the inguinal canal: Clinical presentation, operative management.

Background: An Amyand’s hernia is a right inguinal hernia that contains the appendix in the hernia sac. Mucinous adenocarcinoma of the vermiform appendix is a rare neoplasm commonly discovered through the histology report of a presumed appendicitis specimen or as the cause of pseudomyxoma peritonei. It is very rare for the two entities to co-exist and present as an incarcerated right inguinal hernia. Case Summary: We report a rare case of a mucinous appendiceal adenocarcinoma that ruptured towards the confided anatomical space of the inguinal canal. Initial presentation of the patient was with small bowel obstruction and clinical examination revealed a co-existing right inguinal hernia. Exploratory laparotomy findings revealed an appendiceal mucinous adenocarcinoma invading the adjacent bowel loops and identified an encapsulated collection of mucinous material extended into the inguinal canal and lateral abdominal wall. He underwent a right hemicolectomy with excision of the adjacent small bowel loops and the affected abdominal wall. Conclusion: As the patient presented with a long-standing history of inconsistent symptoms, he underwent thorough preoperative investigations which revealed the true extend of the underlying disease and led to appropriate surgical intervention. The fact that the tumour extended towards the confided space of the inguinal canal prevented the development of pseudomyxoma peritonei. It remains to be examined if such cases, where the mucinous material is contained bare a favourable prognosis.

Long-Term Outcomes after Surgery for Appendiceal Mucinous Tumours

Background: Appendiceal mucinous tumour (AMT) is a very uncommon disease. We aimed to evaluate preoperative and postoperative characteristics as well as long-term outcomes of patients with appendiceal mucinous adenomas and peritoneal pseudomyxoma (PMP). Methods: A consecutive cohort of patients diagnosed with AMT were included in the study. Tumour recurrence and the development of PMP was diagnosed based on the patients' complaints, physical examination, imaging studies, and biopsy results. The calculation of survival rates was performed using the Kaplan-Meier method. Results: Between January 2003 and February 2013, 25 patients had AMT. 15 patients underwent appendectomy only (60%), 5 patients (20%) right hemicolectomy, 4 patients (16%) cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC), and 1 patient (4%) appendectomy with caecal resection. Another 2 patients underwent CRS and HIPEC 4 days and 3 years, respectively, following initial appendectomy. In the histopathologic examination, adenoma was diagnosed in 12 patients (48%); among these, low-grade PMP was found in 1 patient (4%). Low-grade appendiceal mucinous adenocarcinoma (AMCa) was diagnosed in 11 patients (44%); among these, low-grade PMP was found in seven cases (28%) and high-grade AMCa was diagnosed in 2 patients (8%). 2 of 8 PMP patients did not undergo CRS ± HIPEC because of comorbidities. The 5-year overall survival was 100% for the adenomas and 62% for PMP patients. Conclusion: AMT is a very rare entity with a considerably good outcome even in disseminated disease. CRS and HIPEC is a gold standard treatment for PMP with excellent prognosis. However, our results could still be improved in the future.