Use of early postoperative intraperitoneal 5-fluorouracil with index cytoreduction improves survival with secondary cytoreductive surgery.

BACKGROUND: In patients with appendiceal mucinous neoplasm with peritoneal dissemination, a cytoreductive surgery (CRS) with perioperative chemotherapy may result in long-term survival. Disease progression may require secondary cytoreductive surgery (SCRS) and other treatments in selected patients to improve survival and preserve an optimal quality of life. METHODS: The clinical- and treatment-related variables associated with the index CRS and SCRS were statistically assessed for impact on survival after SCRS. RESULTS: A total of 186 of 687 complete CRS patients (27.1%) had SCRS. Median follow-up was 10 years and median survival was 12 years. In 95 males (51%) the median age was 45.0 years. Survival benefit with SCRS was observed if early postoperative intraperitoneal chemotherapy (EPIC) with 5-fluorouracil (EPIC 5-FU) or hyperthermic intraperitoneal chemotherapy (HIPEC) plus EPIC 5-FU was used with the index CRS (hazard ratio [HR]: 0.6, p = 0.0360; HR: 0.4, p = 0.0004, respectively). By propensity matching of 51 pairs of patients, EPIC 5-FU used with index CRS caused a survival advantage compared to HIPEC alone (p = 0.0100) with index CRS (p = 0.0100). CONCLUSIONS: Use of EPIC 5-FU at a complete index CRS was a prognostic variable that improved survival in patients requiring SCRS. Further investigations into the benefits of antiadhesion treatments with CRS and HIPEC are warranted.

Occult appendix pathology in patients undergoing colorectal cancer resection and prophylactic appendectomy.

BACKGROUND: The risk-benefit balance of prophylactic appendectomy in patients undergoing left colorectal cancer resection is unclear. The aim of this report is to assess the proportion of histologically abnormal appendices in patients undergoing colorectal cancer resection in a unit where standard of care is appendectomy, with consent, when left-sided resection is performed. METHODS: A retrospective study on a prospectively collected database was conducted in a single tertiary-care center. Overall, 717 consecutive patients undergoing colorectal cancer resection between January 2015 and June 2021 were analyzed. The primary outcome was the proportion of histologically abnormal appendix specimens at prophylactic appendectomy. The secondary outcome was complications from prophylactic appendectomy. RESULTS: Overall, 576/717 (80%) patients had appendectomy at colorectal cancer surgery. In total, 234/576 (41%) had a right-/extended-right hemicolectomy or subtotal colectomy which incorporates appendectomy, and 342/576 (59%) had left-sided resection (left-hemicolectomy, anterior resection or abdominoperineal excision) with prophylactic appendectomy. At definitive histology, 534/576 (92.7%) had a normal appendix. The remaining 42/576 (7.3%) showed abnormal findings, including: 14/576 (2.4%) inflammatory appendix pathology, 2/576 (0.3%) endometriosis, 8/576 (1.4%) hyperplastic polyp, and 18/576 (3.1%) appendix tumors, which encompassed six low-grade appendiceal mucinous neoplasms (LAMNs), three carcinoids, and nine serrated polyps. In the 342 patients who had prophylactic appendectomy, 10 (2.9%) had a neoplasm (two LAMN, three carcinoids, and five serrated polyps). There were no complications attributable to appendectomy. CONCLUSION: Occult appendix pathology in patients undergoing colorectal cancer resection is uncommon when prophylactic appendectomy was performed. However, approximately 3% of patients had a synchronous appendix neoplasm.

Low-grade appendiceal mucinous neoplasm encountered during risk-reducing salpingo-oophorectomy: A case of laparoscopic surgery.

Low-grade appendiceal mucinous neoplasm (LAMN) is a rare epithelial malignancy of the appendix. If it perforates the abdominal cavity, it can cause a serious clinical syndrome called pseudomyxoma peritonei. In the present case, we laparoscopically removed a LAMN encountered during risk-reducing salpingo-oophorectomy (RRSO). The patient was a 53-year-old woman who was diagnosed with hereditary breast and ovarian cancer syndrome. RRSO was planned, and magnetic resonance imaging revealed a large cystic tumor in the right lower abdomen. We expected an ovarian cyst; however, it was a primary tumor of the appendix. Partial cecal resection was performed laparoscopically by a surgical oncologist. The pathological diagnosis was LAMN. Gynecologists may encounter this disease incidentally. Mucinous appendiceal neoplasm (MAN) may be encountered during RRSO. If a right lower abdominal mass is found near a normal ovary preoperatively, gynecologists should consider MAN as well as paraovarian cyst.

Outcomes of laparoscopic single-incision caecal pole resection for low-grade appendiceal mucinous neoplasm.

Introduction: Low-grade appendiceal mucinous neoplasm (LAMN) is a rare disease, and its clinical course varies from an incidental finding without symptoms to pseudomyxoma peritonei. Furthermore, there are few established treatment guidelines. This study was designed to confirm the outcomes in patients diagnosed with LAMN who underwent single-incision laparoscopic caecal pole resection. Patients and Methods: This study was conducted on pathologically confirmed LAMNs from patients who underwent surgery at a single centre, a tertiary institution, from July 2016 to August 2022. Patients diagnosed with LAMN as a result of biopsy were included. All surgeries were performed with single-incision laparoscopic caecal pole resection by a single surgeon. Results: A total of 70 patients were included. The median age was 65.5 years and 36 (51.4%) patients were female. The baseline carcinoembryonic antigen (CEA) was 8.08 ng/mL (0.76-148.11). The mean maximum diameter was 29.4 mm (7-70) and calcification was seen in 22 cases on pre-operative computed tomography (CT). As a result of histological examination, all patients were marginally negative. The larger the tumour size, the higher the CEA was (P = 0.011), and it was often accompanied by calcification (P = 0.021). In addition, tumour size and CEA showed a positive partial correlation with each other (r = 0.318, P = 0.018). The overall median follow-up period was 22.7 months (2-60). One case had suspected of recurrence on CT scan performed at 33 months following the surgery, but there were no related symptoms. Conclusion: Single-port laparoscopic caecal pole resection without margin involvement in LAMN was safe and feasible, and showed a favourable long-term outcome.

Single-incision laparoscopic surgery compared to conventional laparoscopic surgery for appendiceal mucocele: a series of 116 patients.

BACKGROUND: Although the safety and feasibility of conventional laparoscopic surgery (CLS) for appendiceal mucocele (AM) has been reported, studies on single-incision laparoscopic surgery (SILS) for AM have not been reported. Here, we aimed to compare the perioperative and short-term outcomes between SILS and CLS for AM and to evaluate the oncological safety of SILS. METHODS: We retrospectively analyzed the medical records of patients, diagnosed based on computed tomography findings, who underwent laparoscopic surgery for AM between 2010 and 2018 at one institution. We excluded patients strongly suspected of having malignant lesions and those with preoperative appendiceal perforation. Patients were divided into two groups-CLS and SILS. Pathological outcomes and long-term results were investigated. The median follow-up period was 43.7 (range: 12.3-118.5) months. RESULTS: Ultimately, 116 patients (CLS = 68, SILS = 48) were enrolled. Patient demographic characteristics did not differ between the groups. The preoperative mucocele diameter was greater in the CLS than in the SILS group (3.2 ± 2.9 cm vs. 2.3 ± 1.4 cm, P = 0.029). More extensive surgery (right hemicolectomies and ileocecectomies) was performed in the CLS than in the SILS group (P = 0.014). Intraoperative perforation developed in only one patient per group. For appendectomies and cecectomies, the CLS group exhibited a longer operation time than the SILS group (63.3 ± 24.5 min vs. 52.4 ± 17.3 min, P = 0.014); the same was noted for length of postoperative hospital stay (2.9 ± 1.8 days vs. 1.7 ± 0.6 days, P < 0.001). The most common AM etiology was low-grade appendiceal mucinous neoplasm (71/116 [61.2%] patients); none of the patients exhibited mucinous cystadenocarcinoma. Among these 71 patients, there were 8 patients with microscopic appendiceal perforation or positive resection margins. No recurrence was detected. CONCLUSIONS: SILS for AM is feasible and safe perioperatively and in the short-term and yields favorable oncological outcomes. Despite the retrospective nature of the study, SILS may be suitable after careful selection of AM patients.

Recurrence of initially localized appendiceal mucinous neoplasms after radical resection: survey analysis and literature review.

BACKGROUND: Appendiceal mucinous neoplasm (AMN) is a rare tumor that may be successfully treated by appendectomy. However, some patients develop recurrence as pseudomyxoma peritonei. The present study investigated the recurrence rate after radial resection for AMN. METHODS: A survey on AMN was sent to 171 institutions, and 286 cases were analyzed. The risk of recurrence was assessed according to clinical parameters. Recurrence rates were compared with data from the literature. RESULTS: There were 250 cases in the low-grade group and 36 in the high-grade group, with perforation being detected in 50 cases. After a median follow-up period of 30 months, recurrence was detected in 17 cases, including 12 with high-grade histology and 10 with perforation. Two patients with low-grade histology and no perforation developed recurrence. Independent prognostic factors for recurrence were high-grade histology (p = 0.0001, RR = 8.56) and perforation (p = 0.0168, RR = 3.45). Four groups were classified by histology and perforation: group A: high-grade, perforation ( +), group B: high-grade, perforation (-), group C: low-grade, perforation ( +), group D: low-grade, perforation (-). Five-year recurrence rates in groups A, B, C, and D were 46.7, 25.9, 13.3, and 1.5%, respectively. All cases of recurrence were detected within 3 years, except for two in group B. CONCLUSIONS: Recurrence in cases with low-grade histology and no perforation was rare; however, a postoperative survey for at least 3 years is required. In contrast, cases with high-grade histology or perforation need to be monitored using a similar approach to colon cancer. Prophylactic CRS + HIPEC may be considered.

Multiple intestinal hemangioma concurrent with low-grade appendiceal mucinous neoplasm presenting as intussusception-a case report and literature review.

BACKGROUND: Cases with intussusception caused by either intestinal hemangiomas or appendiceal mucinous neoplasms are extremely rare. CASE PRESENTATION: In this study, we reported a 47-year-old male presented with paroxysmal abdominal pain and postprandial bloating for 3 days. CT results indicated a high possibility of secondary intussusception in ascending colon. Histopathology indicated a mixed type of cavernous and capillary hemangioma, combined with low-grade appendiceal mucinous neoplasms (LAMNs) and intestinal obstruction. The patient underwent laparotomy and right hemicolectomy. Finally, the patient was followed up for 4 months with no disease progression. CONCLUSIONS: Rare studies reported the intestine hemangiomas coincided with appendix low-grade mucinous tumor. Its manifestations are not specific, which is a challenge in the preoperative diagnosis. For cases with intussusception that was not observed in time, it may lead to intestinal necrosis and diffuse peritonitis. Additionally, the ruptured mucinous tumor in the appendix may lead to pathogenesis of pseudomyxoma peritonei. Therefore, accurate diagnosis and appropriate surgery-based treatment contribute to the improvement of prognosis and severe outcomes among these patients.

Clinicopathological Characteristics of Low-Grade Appendiceal Mucinous Neoplasm.

INTRODUCTION: Recently, "low-grade appendiceal mucinous neoplasms" (LAMNs) have been proposed as one subtype of appendiceal mucinous neoplasms, characterized by a villous or flat proliferation of mucinous epithelium with low-grade cytologic atypia. The aim of this study was to clarify the clinicopathological characteristics of LAMN. METHODS: In this multi-institutional cohort study, we retrospectively analyzed the clinicopathological characteristics in appendiceal neoplasms patients who underwent treatment from 2000 to 2017. RESULTS: In total, 922 patients were enrolled, with 279 (30.3%) cases of LAMN, and 93 (10.1%) cases of non-LAMN disease. In comparison with patients with non-LAMN disease, those with LAMN had significantly lower levels of CA19-9 (p = 0.045), a lower frequency of T4 tumors (p < 0.0001), a lower frequency of lymph node metastasis (p < 0.0001), and a lower frequency of distant metastasis (p < 0.0001). Survival analysis revealed that patients with LAMN had a significantly better prognosis than did those with non-LAMN disease (p < 0.001). Among the patients with distant metastasis, those with LAMN had a significantly better prognosis than did those with non-LAMN disease (p = 0.0020), but among the patients without distant metastasis, the difference between the 2 groups was not significant (p = 0.26). However, among patients who underwent complete resection, the difference in prognosis between the 2 groups was not significant (p = 0.10). CONCLUSIONS: A multicenter retrospective study revealed that the clinicopathological characteristics of LAMN was different from those of non-LAMN.

Gross mucinous multinodular appearance aids in the identification of ovarian metastases in low-grade appendiceal mucinous neoplasms during intraoperative consultation.

Ovarian metastases of low-grade appendiceal mucinous neoplasms (LAMNs) show grossly abundant nodular mucous cells, with a gross mucinous multinodular appearance and a histological resemblance to primary ovarian mucinous tumors (POMTs). This study aimed to elucidate the utility of gross features including the gross mucinous multinodular appearance and available clinical information at the time of intraoperative consultation, in distinguishing the ovarian metastases of LAMNs from POMTs or the ovarian metastases of colorectal cancer (CRC). In total, 776 patients with primary ovarian tumor and 68 patients with ovarian metastases underwent intraoperative consultation during 1998-2018. Of the total cases, 4 ovarian metastases of LAMNs, 19 ovarian metastases of CRC, and 50 POMTs (36 borderline tumors and 14 carcinomas) were identified. The gross features including the gross mucinous multinodular appearance were analyzed based on the gross photographs obtained before formalin fixation and the available clinical information collected during intraoperative consultation. The analysis indicated that the ovarian metastases of LAMNs significantly presented with gross mucinous multinodular appearance (4/4 vs. 0/50, P < 0.0001), extraovarian disease (4/4 vs. 2/50, P < 0.0001), ovarian surface involvement (3/4 vs. 2/50, P = 0.0016), and abnormal appendix (4/4 vs. 0/50, P < 0.0001) as compared to POMT. Moreover, the gross mucinous multinodular appearance was a distinguishable feature between the ovarian metastases of LAMNs and ovarian metastases of CRC (4/4 vs. 0/19, P = 0.0001). Based on these results, we proposed an algorithm to diagnose ovarian tumors using the gross mucinous multinodular appearance. Thus, recognizing unique gross features including the gross mucinous multinodular appearance would be useful for both pathologists and surgeons to accurately diagnose ovarian metastases of LAMNs during intraoperative consultation.

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.

The inverted appendix - a potentially problematic diagnosis: clinicopathologic analysis of 21 cases.

AIMS: Inverted appendices are rare, but have the potential to cause diagnostic confusion among endoscopists and pathologists. The aim of this study was to describe the clinicopathological features of inverted appendices seen at our institution over the last 30 years. METHODS AND RESULTS: Twenty-one inverted appendices were identified and the clinical and pathological features reviewed. Patients were predominantly middle-aged women. Most cases were detected incidentally on colonoscopy. Endoscopically, inverted appendices appeared polypoid in the proximal caecum. All resections featured associated pathological processes, including endometriosis (n = 3), inflammatory mucocoele (n = 1), low-grade appendiceal mucinous neoplasm (n = 2), traditional serrated adenoma (n = 1) and inflammatory fibroid polyp (n = 1). Five cases were endoscopically mischaracterised as caecal polyps and removed via polypectomy; initial pathological impressions were erroneous in most cases. All polypectomies featured a dome-like configuration covered by mucosa on the convex surface; the majority had aggregates of ganglion cells and neural plexi embedded in muscularis propria. The vast majority of cases, regardless of the procedure, showed lymphoid aggregates. Among post-polypectomy patients with follow-up, none experienced perforation-associated morbidity despite the histological presence of muscularis propria. CONCLUSIONS: The diagnosis of an inverted appendix should be considered in polypectomy specimens from the caecum or appendiceal orifice with (i) dome-like tissue configuration covered by mucosa on the convex surface, (ii) a deep, robust smooth muscle component with ganglion cells (muscularis propria) and (iii) associated lymphoid aggregates. Prompt recognition on H&E will avoid unnecessary time and resource investment.

Complicated appendiceal diverticulosis versus low-grade appendiceal mucinous neoplasms: a major diagnostic dilemma.

AIMS: To research and identify how often complicated diverticular disease of the appendix [appendiceal diverticular disease (ADD)] shows histological mimicry of low-grade appendiceal mucinous neoplasms (LAMNs) and to provide guidance on the useful histopathological features that allow the appropriate diagnosis to be made. METHODS AND RESULTS: Seventy-four cases of complicated appendiceal diverticular disease were identified from two specialist centres. Of the second opinion/consultation cases, 71% of the ADD cases had been diagnosed by referring pathologists as LAMNs. Salient pathological features were identified and agreed upon to reach the applicable diagnosis. For a diagnosis of complicated diverticulosis, particularly when associated with mucus cysts, the following morphological features were regarded as important: relative retention of the normal mucosal architecture with lamina propria and a maintained crypt architecture, crypts arranged in regular array, epithelial hyperplasia and a lack of nuclear abnormalities extending the length of the crypts. In a formal case-control study undertaken on 30 cases with each diagnosis, ADD and LAMN, loss of lamina propria, a filiform architecture and hypermucinosis were significantly associated with low-grade appendiceal mucinous neoplasms. Mucosal neuromas were significantly associated with diverticular disease of the appendix. CONCLUSIONS: To our knowledge, this study represents the largest series in the world literature and serves to highlight the important pathological features to distinguish complicated diverticular disease of the appendix from LAMNs, and emphasises the difficulties experienced by diagnostic pathologists in diagnosing complicated appendiceal diverticulosis. This is important, as LAMNs have a significant risk of transcoelomic spread, while complicated appendiceal diverticulosis has no such risk.

Zap it track it: the application of Lean Six Sigma methods to improve the screening system of low-grade mucinous neoplasms of the appendix in an acute hospital setting.

OBJECTIVE: To improve the number of patients receiving annual computed tomography (CT) scan and tumour markers, who are diagnosed with low-grade mucinous neoplasms (LAMN). DESIGN: A pre-/post-intervention design was employed using Lean Six Sigma methods to identify gaps in the screening system and to develop and implement solutions for a more robust, auditable screening programme. SETTING: The patients diagnosed with LAMN of the appendix referred to the acute hospital and are enrolled in the screening service. PARTICIPANTS: Consultant colorectal surgeons, cancer nurse specialist, colorectal medical team and quality improvement staff. INTERVENTIONS: Diagnostic tools identified gaps in the current process. A set of improvements were implemented to standardize the pathway for referral and surveillance of patients, provide information on the condition and treatment and standardize and track information received by patients and their referring hospital. MAIN OUTCOME MEASURE(S): Pre and post-intervention outcome measures were taken for the number of patients who receive an annual CT of thoracic, abdomen and peritoneum and tumour markers and number of patients who receive information and contact details. RESULTS: At baseline, of the 28 patients that met the inclusion criteria only 61% had a correct follow-up. Following the implementation of improvements, 78% of patients had correct follow-up and 90% had received information. CONCLUSIONS: Gaps in the current cancer screening system were identified and improvements implemented a reduced number of patients having an incorrect follow-up. Findings are applicable across all precancerous screening systems irrespective of the type of malignancy. The methods used empowered patients and fostered an interdisciplinary team approach to care.

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

AIM: Pseudomyxoma peritonei (PMP) is a rare neoplasm of the appendix, which if untreated disseminates throughout the abdominal cavity and generates considerable morbidity. Since 2002 in the UK, patients with PMP have been managed via two nationally commissioned centres. We evaluated referrals and treatment pathways over time at the Manchester centre. METHOD: Data from all patients referred with suspected PMP were prospectively collected (2002-2015). Definitive treatment was cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy. Disease burden was quantified using the Peritoneal Cancer Index (PCI) (score 0-39) and complete cytoreduction (CC) defined by scores of 0/1. Novel treatment algorithms were developed for patients with low grade appendiceal mucinous neoplasm (LAMN) localized to the peri-appendiceal tissue. RESULTS: In all, 817 patients with confirmed PMP were referred increasing from 11 in 2002 to 103 in 2015. Disease burden was high with a mean PCI of 31 in the first quartile (Q1), levelling off to 15, 15, 17 thereafter (P = 0.002). The proportion of CC0/1 increased from 67% in Q1 to 77% Q2 and 74% Q3/4. Where complete cytoreduction was achieved, 5- and 10-year overall survival was 77% and 66%. The proportion of patients referred with localized LAMN increased over time reaching 25% each year since 2010 (Ptrend  < 0.0001). Two-thirds of localized LAMN now undergo laparoscopically assisted risk-reducing CRS. CONCLUSION: The establishment of a national treatment centre was associated with an initial presentation of patients with advanced disease. The programme has demonstrated a clear trend over time towards earlier referral and adoption of minimally invasive techniques for localized disease.

Low-grade appendiceal mucinous neoplasm and endometriosis of the appendix.

BACKGROUND: A distended, mucous-filled appendix is known as an appendiceal mucocele. They are a rare form of an appendiceal mass and develop from both benign and malignant processes. Mucoceles can develop secondarily to an obstruction, such as from a fecalith, scarring or, rarely, endometriosis. Only 12 cases of non-neoplastic appendiceal mucoceles caused by endometriosis have been previously described. The association between neoplastic appendiceal mucoceles in the presence of endometriosis is described for the first time in this report. CASE PRESENTATION: A 57-year-old woman presented with a chief complaint of worsening abdominal pain over the past 3 months. Imaging studies revealed an appendiceal mass. Laparoscopic evaluation confirmed an appendiceal mucocele, and the patient underwent complete appendectomy. No evidence of mucinous or endometrial deposits were present within the abdominal cavity. Pathological diagnosis revealed low-grade appendiceal mucinous neoplasm (LAMN) with evidence of endometriosis within the muscularis propria of the appendix. The patient recovered without complications and her abdominal pain completely resolved. CONCLUSIONS: Endometriosis of the appendix is a rare manifestation and is most often identified as an incidental finding. Endometriosis leading to an obstructive mucocele of the appendix is an exceedingly rare finding, having only been described 12 times in the medical literature. LAMN in the presence of endometriosis of the appendix is described for the first time in this report. The association between appendiceal neoplasms in the presence of endometriosis requires further research in order to optimize operative treatment.

Immunohistochemical characterization of appendiceal mucinous neoplasms and the value of special AT-rich sequence-binding protein 2 in their distinction from primary ovarian mucinous tumours.

AIMS: The distinction between primary ovarian mucinous tumours and appendiceal mucinous neoplasms metastatic to the ovary can be challenging, given the overlap of morphological features and immunohistochemical expression of traditional markers. Special AT-rich sequence-binding protein 2 (SATB2) has recently been described as a sensitive and specific marker of colorectal epithelium. This study was to determine its expression in appendiceal mucinous tumours and its role in their distinction from ovarian neoplasms. METHODS AND RESULTS: Immunohistochemistry was performed in tissue microarrays from 32 primary appendiceal mucinous tumours (25 low-grade appendiceal mucinous neoplasms and seven adenocarcinomas) and 40 ovarian mucinous neoplasms (20 borderline tumours and 20 adenocarcinomas). Stains were interpreted as positive or negative by scoring intensity and distribution. SATB2 was positive in 93.8% of appendiceal tumours and in only one ovarian tumour; SATB2 was 97.5% specific for appendiceal origin. CK20, CDX2 and MUC2 were strongly and diffusely positive in appendiceal tumours; ovarian tumours were also positive, but with a patchy distribution and mild intensity. CK7 was expressed in 97.5% of ovarian tumours and in 31.2% of appendiceal tumours. PAX8 was positive in 70% of ovarian tumours, and negative in all appendiceal lesions. CONCLUSIONS: SATB2 is frequently expressed in appendiceal mucinous neoplasms. In the context of a mucinous neoplasm involving the ovary, any SATB2 positivity should raise the possibility of appendiceal origin. Expression of CK20, CDX2 and MUC2 supports appendiceal origin only when diffuse and strong. These and other markers, such as CK7 and PAX8, are recommended in the work-up of ovarian mucinous tumours with any clinical or pathological features suggestive of secondary origin.

Appendiceal neoplasms derived from appendiceal tip remnants following appendectomy: a report of two cases.

BACKGROUND: Neoplasms derived from remnant appendix are rarely described, with most cases arising from the appendiceal "stump". Here, we present two surgical cases of appendiceal neoplasms derived from appendiceal "tip" remnants. CASE PRESENTATION: The first patient was a 71-year-old man who had undergone laparoscopic appendectomy for acute appendicitis 12 years prior. During appendectomy, the appendiceal root was ligated, but the appendix was not completely removed due to severe inflammation. At the most recent presentation, computed tomography (CT) was performed to examine choledocholithiasis, which incidentally revealed a cystic lesion of approximately 90 mm adjacent to the cecum. A retrospective review revealed that the cystic lesion had increased in size over time, and laparoscopic ileocecal resection was performed. Pathology revealed no continuity from the appendiceal orifice to the cyst, and a diagnosis of low-grade appendiceal mucinous neoplasm (LAMN) was made from the appendiceal tip remnant. The patient was discharged without complications. The second patient was a 65-year-old man who had undergone surgery for peritonitis due to severe appendicitis 21 years prior. During this operation, the appendix could not be clearly identified due to severe inflammation; consequently, cecal resection was performed. He was referred to our department with a chief complaint of general fatigue and loss of appetite and a cystic lesion of approximately 85 mm close to the cecum that had increased over time. CT showed irregular wall thickening, and malignancy could not be ruled out; therefore, laparoscopic ileocecal resection with D3 lymph node dissection was performed. The pathological diagnosis revealed mucinous adenocarcinoma (TXN0M0) arising from the remnant appendiceal tip. The patient is undergoing follow-up without postoperative adjuvant chemotherapy, with no evidence of pseudomyxoma peritonei or cancer recurrence for 32 months postoperatively. CONCLUSIONS: If appendicitis-associated inflammation is sufficiently severe that accurate identification of the appendix is difficult, it may remain on the apical side of the appendix, even if the root of the appendix is ligated and removed. If the appendectomy is terminated incompletely, it is necessary to check for the presence of a residual appendix postoperatively and provide appropriate follow-up.

Asymptomatic low-grade appendiceal mucinous neoplasm: A case report.

BACKGROUND: Low-grade appendiceal neoplasms (LAMN) are characterized by low incidence and atypical clinical presentations, often leading to misdiagnosis as acute or chronic appendicitis before surgery. The primary diagnostic tool for LAMN is abdominal computed tomography (CT) imaging. Surgical resection remains the cornerstone of LAMN management, necessitating en bloc tumor excision to minimize the risk of iatrogenic rupture. Laparoscopy, known for its minimal invasiveness, reduced postoperative discomfort, and expedited recovery, is a safe and reliable approach for LAMN treatment. Despite the possibility of pseudomyxoma peritonei development, appendectomy and partial appendectomy generally result in negative tumor margins and favorable outcomes, which can be attributed to the disease's slow growth and lower malignancy. CASE SUMMARY: A 71-year-old male patient was admitted to our hospital with a pelvic space-occupying lesion detected 1 mo prior. Physical examination showed a soft abdomen without tenderness or rebound and no palpable masses. No shifting dullness was noted, and digital rectal examination revealed no palpable mass. Enteroscopy revealed a raised, smooth-surfaced mass measuring 3.0 cm in the cecum. Abdominal contrast-enhanced CT showed a markedly thickened and dilated appendix with visible cystic shadows. Laparoscopic surgery was performed and revealed a significantly dilated appendix, leading to laparoscopic resection of the appendix and part of the cecum. Post-surgical pathologic analysis confirmed LAMN. The patient received symptomatic and supportive post-operative care and was discharged on postoperative day 4 without complications such as abdominal bleeding, intestinal obstruction, or incision infection. No tumor recurrence was observed during a 7-mo follow-up period. CONCLUSION: LAMN is a rare disease that lacks specific clinical manifestations. Abdominal CT plays a crucial role in diagnosing LAMN, and laparoscopic surgery is a safe and effective diagnostic and therapeutic approach.

An Incidental Finding of Low-Grade Appendiceal Mucinous Neoplasm in a Case of Borderline Brenner Tumor of the Ovary.

The concurrent presentation of a low-grade appendiceal mucinous neoplasm (LAMN) and a borderline Brenner tumor (BT) of the ovary are exceedingly rare. Brenner tumors stand out as a particularly uncommon form, making up only around 5% of all benign epithelial tumors of the ovary. Among the ovarian Brenner, the borderline subtype is even rarer. Appendiceal neoplasm (LAMN) and right ovarian BT cannot be distinguished due to their anatomical position. LAMN is often an incidental finding and at later stages when left undiagnosed may lead to pseudomyxoma peritonei (PMP). This case describes a postmenopausal woman in her 50s experiencing abdominal pain and bloating for a week. Elevated carcinoembryonic antigen (CEA) levels and imaging suggested a potential right ovarian tumor. Interestingly, it revealed a unique combination of borderline Brenner tumor of the right ovary and low-grade appendiceal mucinous neoplasm.

Mucinous neoplasm of the appendix: A case report and review of literature.

BACKGROUND: Appendiceal mucinous neoplasms (AMNs), although not classified as rare, are relatively uncommon tumors most often discovered incidentally during colorectal surgery. Accurate identification of AMNs is difficult due to non-specific symptoms, overlapping tumor markers with other conditions, and the potential for misdiagnosis. This underscores the urgent need for precision in diagnosis to prevent severe complications. CASE SUMMARY: This case report describes the unexpected discovery and treatment of a low-grade AMN (LAMN) in a 74-year-old man undergoing laparoscopic hemicolectomy for transverse colon adenocarcinoma (AC). Preoperatively, non-specific gastrointestinal symptoms and elevated tumor markers masked the presence of AMN. The tumor, presumed to be an AMN peritoneal cyst intraoperatively, was confirmed as LAMN through histopathological examination. The neoplasm exhibited mucin accumulation and a distinct immunohistochemical profile: Positive for Homeobox protein CDX-2, Cytokeratin 20, special AT-rich sequence-binding protein 2, and Mucin 2 but negative for cytokeratin 7 and Paired box gene 8. This profile aids in distinguishing appendiceal and ovarian mucinous tumors. Postoperative recovery was uncomplicated, and the patient initiated adjuvant chemotherapy for the colon AC. CONCLUSION: This case highlights the diagnostic complexity of AMNs, emphasizing the need for vigilant identification to avert potential complications, such as pseudomyxoma peritonei.