Mucinous appendiceal neoplasms: pathologic classification, clinical implications, imaging spectrum and mimics

Factors Predicting Incidentally Found Appendiceal Tumors Following Appendectomy: Propensity Score Matching Analysis

PurposeThe factors that predict coincidental appendiceal neoplasms in patients who underwent appendectomy due to appendicitis were investigated.Methods5829 patients diagnosed with appendicitis and underwent appendectomy in the department of surgery were examined. Among these patients, patients with appendiceal neoplasia and benign pathology were selected by propensity score matching analysis in a ratio of 1:4. As a result of analysis, 74 and 274 patients were grouped as appendiceal neoplasia and benign pathology, respectively.ResultsThe mean age of the 348 appendiceal neoplasia and benign pathology groups included in the study was 45.6 and 46.4, respectively. Appendiceal diameter, contrast enhancement in the appendix wall, and neutrophil count were independent parameters for appendiceal neoplasia pathology. The AUC value of the combination of appendix diameter, lack of enhancement in the appendix wall, and neutrophil count in distinguishing appendiceal neoplasia pathology was 0.787.ConclusionAppendix diameter, lack of wall enhancement, and neutrophil count are the three predictive indicators useful in helping clinicians suspect appendiceal neoplasms.

Low grade appendiceal mucinous neoplasm mimicking malignant ovarian tumor: A case report

INTRODUCTION

Mucinous appendiceal neoplasms are unique tumors in which >50 % of the tumor volume is composed of extracellular mucin. They may present as an unruptured mucin-filled appendix or, more commonly, with peritoneal metastases after rupture or transmural invasion of the primary tumor. This case report describes a case of presumed ovarian malignancy with final pathologic diagnosis of low grade appendiceal mucinous neoplasm. Due to its rarity, we decided to report it.

CASE PRESENTATION

A 37-year-old patient presented with a compliant of abdominal swelling. Abdominopelvic ultrasound was done and showed huge right and left complex cystic ovarian masses having thick septa. For this, she underwent total abdominal hysterectomy, omentectomy and bilateral salpingo-oophorectomy. On laparotomy there was also incidental finding of ruptured mucin-filled appendix for which appendectomy was done. Histopathology examinations from all resected specimens revealed the diagnosed LAMN. Two weeks after surgical resection, she was started on FOLFOX chemotherapy regimen.

DISCUSSION

Incidence of low grade appendiceal mucinous neoplasm is increasing. In addition to the increasing incidence, lack of early detection and impeded access to optimal multi-disciplinary treatment may worsen survival outcomes. Developing quality diagnostic services in the proper health context is crucial for early diagnosis and successful therapy of LAMN patients, and applying a resource-sensitive approach to prioritize essential treatments based on effectiveness and cost-effectiveness is key to overcoming barriers in low- and middle-income countries.

CONCLUSION

A recognition of mucinous material and abnormal appearing appendix should prompt the surgeon to consider performing an appendectomy to obtain primary pathologic diagnosis.

Low-grade appendiceal mucinous neoplasm: A case report

RATIONALE

Low-grade appendiceal mucinous neoplasm (LAMN) is a clinically rare tumor that predominantly occurs in females and presents with nonspecific symptoms, often resulting in misdiagnosis. While postoperative pathology remains the gold standard for diagnosis, accurate preoperative identification through various diagnostic methods is essential for effective treatment planning. To raise awareness of this condition, we present a case of a middle-aged male diagnosed with LAMN.

PATIENT CONCERNS

A 52-year-old male presented to outpatient clinic with right lower abdominal pain lasting 1 day. He described the pain as continuous cramping, exacerbated by movement and coughing, with associated nausea.

DIAGNOSIS

Physical examination revealed tenderness in the right lower quadrant and a palpable mass measuring approximately 6.5 cm × 5.0 cm, with poor definition and limited mobility. An elevated white blood cell count (16.2 × 109/L) and a mixed cystic and solid mass were noted, prompting admission for further evaluation. Further, abdominal enhanced computed tomography revealed a mixed-density lesion in the right ileocecal region, measuring approximately 6.5 cm × 5.0 cm. This finding was suggestive of an appendiceal mucinous neoplasm, with mucinous adenocarcinoma remaining a possibility that could not be excluded.

INTERVENTIONS

The patient underwent a laparoscopic right hemicolectomy on June 5, 2024, and the gross specimen showed: a 6.5 cm × 5.0 cm mass was found in the appendix area on the surface of the intestinal tube, a large amount of jelly was found after incision, and the mass was connected to the intestinal cavity.

OUTCOMES

The patient recovered well after surgery, the abdominal drainage tube was pulled out on the 8th day after surgery, and the patient was discharged on the 13th day after surgery. Postoperative examination showed LAMN and mucus accumulation in the wall of the appendix with a foreign body giant cell reaction, acute attack of chronic appendicitis, and suppurative inflammation with peripheral inflammation. Postoperative diagnosis: LAMN; acute chronic appendicitis attack.

LESSONS

As a rare clinical gastrointestinal tumor, LAMN lacks specific clinical manifestations, and its diagnosis depends on postoperative examination; however, the indications for surgery are clear and the clinical prognosis is good. The key to surgery is to protect the tumor body to avoid rupture and cause the development of peritoneal pseudomyxoma (PMP).

Silent but Significant: A Case Report of Appendiceal Mucocele

Appendiceal mucocele is a rare disease that can sometimes mimic acute appendicitis or be discovered accidentally during surgeries. The clinical presentation of appendiceal mucocele is observed as lumen distension due to mucin accumulation. This condition has both benign and malignant underlying etiologies, which can be confirmed by histopathological examination. Acute presentation of appendiceal mucocele is rare and mostly resembles the symptoms of acute appendicitis. The treatment of appendiceal mucocele is crucial due to the risk of pseudomyxoma peritonei caused by the spread of mucus, mucocele perforation, or the presence of malignancy such as mucinous carcinoma. Surgical resection, either appendicectomy, typhlectomy, or sometimes right hemicolectomy, is the recommended management approach. This is a case of a 74-year-old male with pain in the abdomen as the major presenting complaint. He had a palpable right iliac fossa mass. The diagnosis of appendiceal mucocele was made by contrast-enhanced computed tomography, which was later confirmed by histopathology. The patient underwent surgical resection and was doing well at the three-month follow-up.

The 'onion skin' sign of a low-grade appendiceal mucinous neoplasm: An incidental finding during early pregnancy assessment

A low-grade appendiceal mucinous neoplasm (LAMN) is a cystic dilatation of the appendix resulting from the accumulation of mucinous secretions caused by a luminal obstruction. Although usually benign, pseudomyxoma peritonei may occur in the event of rupture, and 10% of cases may be secondary to appendiceal cystadenocarcinoma. A LAMN is both more common and more likely to have a malignant association in women, making it an entity with which practitioners of gynaecological ultrasound should be familiar. Although not the primary aim, early pregnancy ultrasound assessments can offer the diagnostic opportunity to identify pelvic pathology. A LAMN can be identified on ultrasonography by visualisation of an adnexal mass separate to the ovary, which due to the layers of secretions has a distinctive appearance previously likened to 'onion-skin' or 'whipped-cream'. Here, we describe an incidental finding of a LAMN during an early pregnancy assessment. Practitioners of early pregnancy ultrasound should be familiar with the characteristic morphology of this rare but important finding.

Lower Gastrointestinal Bleeding Secondary to Appendiceal Mucinous Neoplasm: A Report of Two Cases and a Review of the Literature

Appendicular mucinous neoplasms, constituting less than 1% of gastrointestinal tract neoplasms, are heterogeneous entities. They may be asymptomatic, discovered incidentally, or present as large tumors due to mucin accumulation. The lack of standardized treatment complicates management. Imaging studies, particularly CT scans, are crucial for diagnosis and follow-up. This case report presents two clinical cases of women in their sixth and seventh decades of life with a history of lower gastrointestinal bleeding, mild anemia in laboratory studies, and incomplete colonoscopies. The diagnosis, confirmed through CT scans, led to the decision for surgical intervention in both cases, involving laparoscopic right hemicolectomy with ileotransverse anastomosis. Subsequently, histopathological reports confirmed the diagnosis of high-grade appendicular mucinous neoplasms, and a follow-up plan was established with imaging studies every six months with no recurrence at two years. Over 50% of appendicular tumors are mucinous neoplasms originating from low-grade mucinous neoplasms. Given the low lymph node invasion (2%), appendectomy may suffice if the entire tumor is excised. Extensive resections or right hemicolectomy are reserved for larger tumors or high-grade neoplasms to minimize local recurrence risk. Mucinous neoplasms with acellular mucin and peritoneal invasion may require cytoreduction or right hemicolectomy, while those with mucinous epithelium may need hyperthermic intraperitoneal chemotherapy (HIPEC) due to the risk of local recurrence, worsened by the presence of extra appendiceal epithelial cells. Disease-free and overall survival depend on treatment and initial lesion characterization. A five-year survival rate of 86% is reported for low-grade mucinous neoplasms. Follow-up approaches lack an ideal standard, generally involving physical examinations and imaging studies every six months to one year during the first six years.

Manifestations of Ovarian Cancer in Relation to Other Pelvic Diseases by MRI

Imaging plays a pivotal role in the diagnostic approach of women with suspected ovarian cancer. MRI is widely used for preoperative characterization and risk stratification of adnexal masses. While epithelial ovarian cancer (EOC) has typical findings on MRI; there are several benign and malignant pelvic conditions that may mimic its appearance on imaging. Knowledge of the origin and imaging characteristics of a pelvic mass will help radiologists diagnose ovarian cancer promptly and accurately. Finally, in special subgroups, including adolescents and gravid population, the prevalence of various ovarian tumors differs from that of the general population and there are conditions which uniquely manifest during these periods of life.

Retroperitoneal mass, a rare manifestation of mucinous adenocarcinoma of appendix: A case report

The retroperitoneum (RP) might be affected by a variety of infections, inflammations, and tumors, including benign and malignant ones. Although primary malignant tumors are the most prevalent ones in this anatomic area, metastatic and invasive tumors rarely involve the retroperitoneum. Gastrointestinal stromal tumors (GISTs) are considered as the most common tumors that invade the retroperitoneum, but, to the best of our knowledge, it is the first time a surgery team has encountered the appendiceal tumor as a huge retroperitoneal mass. A 68-year-old man was referred to the emergency department with abdominal distension and weight loss. In his course of hospitalization, a huge right retroperitoneal mass was detected by a computed tomography (CT) scan; after that, the patient underwent laparotomy, evacuation of massive mucinous tissue located in the right retroperitoneum, and right hemicolectomy due to appendiceal tumor. The histopathological examination showed "mucinous appendiceal neoplasm." This is the first case study showing the invasion of an appendiceal tumor through the visceral peritoneum into the retroperitoneum, so an invasion of the peritoneal tumor to the retroperitoneum should be considered when a urologist approaches retroperitoneal masses.

Comparison of the risk of appendiceal tumors in uncomplicated and complicated appendicitis

BACKGROUND

Interval appendectomy or non-operative management is commonly performed for complicated appendicitis in adult patients. However, these treatments are still controversial because the incidence rate of appendiceal tumors recognized after interval appendectomy is reportedly higher than that after emergency appendectomy. Thus, this study aimed to compare the appendiceal tumor rates between uncomplicated and complicated appendicitis.

METHODS

This study was a retrospective review of patients with appendicitis who underwent surgical removal at a single institution over 7.5 years. The primary objective was the comparison of the incidence rate of appendiceal tumors using propensity score matching, and the secondary objective was the same comparison among older patients, defined as patients aged ≥ 60 years.

RESULTS

A total of 1277 patients were included. Of these patients, 297 (23.3%) were preoperatively diagnosed with complicated appendicitis. Moreover, 22 (1.7%) patients, including 14 cases of complicated appendicitis and 8 cases of uncomplicated appendicitis, were diagnosed with appendiceal tumors based on pathological examination. No significant difference was found in the incidence rate of appendiceal tumors between the two groups after matching for patients' background, including age, sex, and history of appendicitis by propensity score matching (P = 0.073). However, among patients aged ≥ 60 years, the incidence of appendiceal tumors was significantly higher in complicated than in uncomplicated appendicitis (P = 0.006).

CONCLUSIONS

Although the overall risk of appendiceal tumors did not differ between complicated and uncomplicated appendicitis when analyzed by the propensity score matching, in older patients aged ≥ 60 years, the risk increased among those with complicated appendicitis. Therefore, although the incidence is low, complicated appendicitis, particularly, among older patients, should be examined carefully and be performed IA when unusual findings exist.

MRI of Borderline Epithelial Ovarian Tumors: Pathologic Correlation and Diagnostic Challenges

Borderline epithelial ovarian tumors are a distinct pathologic entity characterized by increased epithelial proliferation and nuclear atypia, but without frank stromal invasion. Borderline tumor (BT) is now considered to represent an intermediate phase in the stepwise progression from benign to malignant ovarian epithelial tumor. Since BTs commonly manifest at early stages in women of reproductive age and are associated with a good prognosis, making the correct diagnosis is important in determining whether a patient is a candidate for fertility-sparing surgery. There are six histologic BT subtypes (serous, mucinous, seromucinous, endometrioid, clear cell, and Brenner), and each has different MRI features, reflecting their unique histologic architectures. Radiologists should be aware of the MRI features that can suggest BTs. These features include a hyperintense papillary architecture with hypointense internal branching, which can be observed with serous and seromucinous BTs on T2-weighted images; aggregates of microcysts that have hypointensity on T2-weighted images and reticular enhancement on contrast-enhanced T2-weighted images, which can be seen with mucinous BTs; and moderately high signal intensity on diffusion-weighted images along with relatively high apparent diffusion coefficient values, which can be observed regardless of the histologic subtype. Nevertheless, because the imaging features of BTs overlap with those of many benign lesions (eg, cystadenoma and cystadenofibroma, decidualized endometriosis, and polypoid endometriosis) and malignant tumors (ovarian cancers and metastases), histologic confirmation is required for the final diagnosis. Special emphasis is placed on the MRI features of BTs, pathologic correlation, and the challenges related to diagnosis. ^©RSNA, 2022.

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.

Mucocele of the appendix: what to expect

Mucoceles of the appendix are rare and can have quite variable imaging and clinical presentations, sometimes mimicking an adnexal mass. The underlying cause can be neoplastic or non-neoplastic. The typical imaging appearance of a mucocele of the appendix is that of a cystic structure with a tubular morphology. This structure is defined by having a blind-ending and being contiguous with the cecum. Radiologists should be familiar with key anatomical landmarks and with the various imaging features of mucoceles of the appendix, in order to provide a meaningful differential diagnosis of a lesion in the right lower abdominal quadrant. In addition, a neoplastic mucocele can rupture, resulting in pseudomyxoma peritonei, which will change the prognosis dramatically. Therefore, prompt diagnostic imaging is crucial.

Repeated cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy in patients with peritoneal carcinomatosis: A retrospective cohort study

Introduction

The prognosis of abdominal cancer with peritoneal carcinomatosis (PC) is poor. In literature, some authors described a repeated Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in patients with recurrent PC as feasible for overall survival improvement. Hence, we implemented this approach at our hospital and analyzed our cases.

Methods

A unicentric retrospective observational study took place at the Helios hospital Berlin-Buch in 2020. The data of individuals who received a HIPEC in the time of 2007-2019 were extracted. The data were entered in the HIPEC database of the German Society of General and Visceral Surgery (StuDoQ|HIPEC, German society for general and visceral surgery). The primary objective was the overall survival after first HIPEC procedure.

Results

A total of 292 data files from were extracted and 14 patients were identified as eligible for further analysis (7× colorectal, 3x gastric, 1× appendix cancer, 1× cancer of unknown primary, 1× Mesothelioma, 1× Pseudomyxoma peritonei). The mean age was 57 (8) years. The BMI was on average 23.5 (3.5) kg/m². A total of 8 individuals were female and 6 male (6xASA-Score I, 8xASA-Score II). The initial Peritoneal Cancer Index (PCI) was on average 11.5 (9.1). The average overall survival after 1. HIPEC for colonic cancer was 74 months (n = 3; 43, 70 and 90 month), for gastric cancer 29 months (n = 2; 19 and 39 month) and for mesothelioma 44 months (n = 1).

Conclusions

Based on our findings Repeated Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy may improve overall survival of selected patients suffering from peritoneal carcinomatosis.

Necessity of posttreatment surveillance for low-grade appendiceal mucinous neoplasms

BACKGROUND AND OBJECTIVES

Low-grade appendiceal mucinous neoplasms (LAMNs) are generally treated by surgical resection, but posttreatment surveillance protocols are not well-established. The objectives of this study were to characterize posttreatment surveillance and determine the risk of recurrence following surgical resection of LAMN.

METHODS

Patients who underwent surgical resection of localized LAMNs in an 11-hospital regional healthcare system from 2000 to 2019 were identified. Posttreatment surveillance regimens were characterized, and rates of disease recurrence were evaluated.

RESULTS

A total of 114 patients with LAMNs were identified. T-category was pTis for 92 patients (80.7%), pT3 for 7 (6.1%), pT4a for 14 (12.3%), and pT4b for 1 (0.9%). Two patients (1.8%) had a positive resection margin. Posttreatment surveillance was performed for 39 (34.2%) patients and consisted of office visits for 32 (82%) patients, computerized tomography imaging for 30 (77%), magnetic resonance imaging for 5 (13%), colonoscopy for 15 (38%), and serum tumor marker measurement for 12 (31%). After a mean follow-up duration of 4.7 years, no patients experienced tumor recurrence.

CONCLUSIONS

Posttreatment surveillance is common among patients with LAMNs. However, no patients experienced tumor recurrence, regardless of T-category or margin status, suggesting that routine surveillance following surgical resection of LAMN may be unnecessary.

Surveillance Colonoscopy Revealing Asymptomatic Low-Grade Appendiceal Mucinous Neoplasm

Appendicular mucinous neoplasms are a collection of rare tumors with diverse clinical presentations and pathologic potential, which can cause diagnostic and therapeutic challenges. Traditionally, they are diagnosed by radiologic imaging or identified intraoperatively; however, rarely, they may be diagnosed during an endoscopic procedure. In this unusual case, we present the case of a 62-year-old Caucasian male undergoing routine surveillance colonoscopy due to a history of colonic neoplasia. During the colonoscopy, a submucosal, non-bleeding 1cm mass of benign appearance was found in the appendix. Further workup determined the mass was likely a mucocele, and surgical consultation was recommended. The patient denied any symptoms suggestive of a mucinous neoplasm prior to and during evaluation. A laparoscopic appendectomy was subsequently performed, and the histopathology report confirmed the diagnosis of a low-grade appendiceal mucinous neoplasm. The patient recovered without complications and continued to deny any symptoms during his postoperative course and follow-up care. Given their rare incidence and unpredictable nature, appendiceal mucinous neoplasms remain difficult to identify. Discovering a low-grade mucinous neoplasm in an asymptomatic patient via colonoscopy illustrates the spectrum of unique presentations and modalities for diagnosis.

Endoscopic diagnosis and treatment of an appendiceal mucocele: A case report

BACKGROUND

Appendiceal mucocele is a rare disease that causes obstructive dilatation of the appendix due to the intraluminal accumulation of mucin. We report a case of endoscopic diagnosis and treatment of an appendiceal mucocele.

CASE SUMMARY

A 47-year-old man presented with a protrusion around the orifice of the appendix discovered by colonoscopy incidentally. He was admitted to our hospital for a routine checkup without any symptoms. Abdominal computed tomography showed a cystic mass approximately 3 cm in diameter with fat stranding. The preoperative diagnosis was non-neoplastic appendiceal mucocele, and endoscopic treatment was performed. The endoscopic findings and pathological results supported our preoperative diagnosis. The endoscopic treatment of appendiceal mucocele was feasible and effective, which was confirmed by repeated endoscopy and post-operative computed tomography after 7 mo.

CONCLUSION

Endoscopic therapy provides a new method for the treatment of appendiceal mucocele.

Surgical Outcomes of Single-Port Laparoscopic Surgery Compared With Conventional Laparoscopic Surgery for Appendiceal Mucinous Neoplasm

PURPOSE

This study aimed to evaluate the safety and feasibility of single-port laparoscopic surgery (SLS) for appendiceal mucinous neoplasm (AMN) when compared with conventional laparoscopic surgery (CLS).

METHODS

This retrospective study enrolled patients who underwent surgery for AMN between July 2014 and June 2020 at Seoul National University Bundang Hospital. Patient demographics, surgical data, pathology, hospital stay, postoperative morbidity, and follow-up data were extracted from electronic records for analysis.

RESULTS

We enrolled 18 patients who underwent SLS and 22 who underwent CLS. The SLS group included patients who underwent partial cecectomy (14 patients), ileocecectomy (3 patients), and right hemicolectomy (1 patient). The CLS group included patients who underwent appendectomy (4 patients), partial cecectomy (11 patients), ileocecectomy (5 patients), and right hemicolectomy (2 patients). Operation type was not significantly different between groups (P = 0.213). No patient required open surgery in the SLS group in contrast to the CLS group (13.6%; P = 0.238). The operative time tended to be shorter in the SLS group than the CLS group (median [interquartile range]: 52.5 minutes [40-65.2 minutes] and 60 minutes [40-120 minutes], respectively; P = 0.251). Morbidity was 5.5% in the SLS group and 9.0% in the CLS group (P = 0.692). Surgical margins were clear in all cases. The median duration of postoperative hospital stay was 2.0 and 4.0 days in the SLS and CLS groups, respectively (P = 0.013). No recurrence occurred in either group during follow-up.

CONCLUSION

This study indicates that SLS is a safe and feasible surgical approach for AMN.

Utility of computed tomography and 18 F-fluorodeoxyglucose with positron emission tomography/computed tomography for distinguishing appendiceal mucocele caused by mucinous adenocarcinoma from other pathologies

AIM

Differentiating appendiceal mucocele with mucinous adenocarcinoma from other pathologies before surgery is difficult. The objective of this study was to evaluate the utility of CT and ¹⁸ F-fluorodeoxyglucose (FDG) with positron emission tomography (PET)/CT for differentiating mucinous adenocarcinoma of appendiceal mucocele from other pathologies.

METHOD

The study included 25 patients who underwent surgery for clinically diagnosed appendiceal mucoceles detected on CT at the University of Tokyo Hospital. Among these patients, 19 underwent FDG-PET/CT preoperatively. We compared features of the CT imaging findings and maximum standard uptake values (SUV_max ) detected by FDG-PET/CT between mucocele with mucinous adenocarcinoma and other pathologies.

RESULTS

A total of 13 men (52%) and 12 women (48%) were included in this study, with a median age of 65 years (range 34-83). There were six patients (24%) with pathologically confirmed mucinous adenocarcinoma, 15 patients (60%) with appendiceal mucinous neoplasm and four patients (16%) with simple mucocele caused by chronic inflammation. On the CT findings, wall irregularity was the only significant feature for the two groups in this study (83.3% vs 0.0%, P < 0.01). There was a significant difference in the SUV_max levels on PET/CT between the two groups (100.0% vs 20.0%, P < 0.01).

CONCLUSION

Distinguishing between mucocele with mucinous adenocarcinoma and other pathologies using imaging modalities is challenging. Our results suggest that wall irregularity on CT and elevated SUV_max on PET/CT are useful factors that can be employed for such discrimination.

Appendicitis mimicking the CT appearance of an appendiceal mucinous neoplasm

Occasionally, radiologically diagnosed acute appendicitis is found to harbour underlying appendiceal neoplasm on post-surgical histopathology. Conversely, a situation in which radiologically, the appendix demonstrates features consistent with an underlying tumour but post-operative pathology finds no evidence of neoplastic change is rare. We describe a case of a 50-year-old man who presented with a markedly dilated "mass-like" appendix with minimal inflammatory changes on a computed tomography scan. Radiological findings were suspicious for an appendiceal neoplasm/mucocele (i.e. low-grade mucinous neoplasm). However, the post-surgical histopathological diagnosis did not concur with the radiological diagnosis and instead demonstrated findings compatible with acute appendicitis without neoplastic change. In this case report we provide a histopathological correlation and an explanation as to how this may have happened with the hope of helping radiologists avoid this pitfall in the future.

CT diagnosis of appendiceal intussusception in a middle-aged female

Appendiceal intussusception is rare with an estimated incidence of 0.01%. Although it is infrequently encountered, the few documented cases of this entity have shown it may mimic or indicate an underlying neoplasm when evaluated with colonoscopy. With the abundant use of multi-detector CT and increased utility of CT colonography, awareness of the radiologic findings of this condition has become increasingly important. Appendiceal intussusception, while potentially pathologic in its own right, may mimic or even coexist with other pathologies, both malignant and benign. We present a case of adult appendiceal intussusception without a "lead point" that was successfully diagnosed by CT imaging.

Late stage diagnosis of mucinous adenocarcinoma of the appendix: a case report of an unusual tumor with a rare presentation

BACKGROUND

The incidence of mucinous appendiceal adenocarcinomas (MAA) has increased over the past three decades. Advanced stage tumor diagnosis is likely attributable to non-specific findings. Here we describe advanced stage appendiceal MAA presenting as inguinal ulcers, scrotal abscesses, and other nonspecific symptoms. To our knowledge, this is the first report of MAA presenting as inguinal pain with inflamed phlegmonous tissue and scrotal abscess.

CASE PRESENTATION

A 67-year-old male presented to a rural facility complaining of weight-loss, fatigue, hematuria, dysuria, painful right inguinal ulceration, and right scrotal abscess drainage. Computed tomography of the abdomen and pelvis revealed a distended appendix (> 1.3 cm) and a fistula between the appendix, urinary bladder, right scrotum, and right groin. Laparoscopic appendectomy was performed and diagnosed as MAA. After a right hemicolectomy, the MAA was staged as pT3b pN0 M0 G2.

CONCLUSION

This case highlights a unique presentation of late stage appendiceal MAA. Due to the increased incidence of appendiceal MAAs, reports of unique clinical features are needed to facilitate early diagnosis and intervention, especially in rural settings with limited access to specialists.

A prospective study of discrepancy between clinical and pathological diagnosis of appendiceal mucinous neoplasm

Purpose

Appendiceal tumoral lesions can occur as benign, malignant, or borderline disease. Determination of the extent of surgery through accurate diagnosis is important in these tumoral lesions. In this study, we assessed the accuracy of preoperative CT and identified the factors affecting diagnosis.

Methods

Patients diagnosed or strongly suspected from July 2016 to June 2019 with appendiceal mucocele or mucinous neoplasm using abdominal CT were included in the study. All the patients underwent single-incision laparoscopic cecectomy with the margin of cecum secured at least 2 cm from the appendiceal base. To compare blood test results and CT findings, the patients were divided into a mucinous and a nonmucinous group according to pathology.

Results

The total number of patients included in this study was 54 and biopsy confirmed appendiceal mucinous neoplasms in 39 of them. With CT, the accuracy of diagnosis was 89.7%. The mean age of the mucinous group was greater than that of the nonmucinous group (P = 0.035). CT showed that the maximum diameter of appendiceal tumor in the mucinous group was greater than that in the nonmucinous group (P < 0.001). Calcification was found only in the appendix of patients in the mucinous group (P = 0.012). Multivariate analysis revealed that lager tumor diameter was a factor of diagnosis for appendiceal mucinous neoplasm.

Conclusion

The accuracy of preoperative diagnosis of appendiceal mucinous neoplasms in this study was 89.7%. Blood test results did not provide differential diagnosis, and the larger the diameter of appendiceal tumor on CT, the more accurate the diagnosis.

Imaging findings for mucinous tumors of the abdomen and pelvis

This article aims to describe the imaging findings for mucinous tumors of the abdomen and pelvis, which have a similar appearance on imaging tests regardless of the organ in which they develop. Due to the high water content of mucus, the appearance of these tumors is generally similar to that of water on ultrasonography, computed tomography, and magnetic resonance imaging. Another common feature of mucin-producing tumors is that calcifications are often present. The rupture of these lesions and accumulation of mucinous material in the peritoneal cavity gives rise to pseudomyxoma peritonei. It is important to identify mucinous tumors because they have a different prognosis and clinical course than non-mucinous tumors and require different management. Depending on their anatomic location and their imaging characteristics, the treatment approach varies from follow-up to radical surgery together with chemotherapy or radiotherapy or both.

Dilated Appendix: Is There More to It? Case Report and Brief Review of Literature with Radiologic-Pathological Correlation

Mucocele of the appendix is rare and represents only the tip of the iceberg of underlying benign and malignant pathological processes. Intraoperative diagnosis is also tricky because the inflammation of the appendix often hides the tumor. The preoperative diagnosis is essential to differentiate appendiceal mucocele from acute appendicitis as the treatment varies from open surgical versus laparoscopic surgical approach and for decreasing intraoperative and postoperative morbidity and mortality rate. We present three cases of appendiceal mucocele. The purpose of this paper is to make the physicians aware of the entity, its associations and the effect on management. This review will provide radiologic and pathologic correlation for the preoperative diagnosis of benign and malignant causative processes and differential diagnostic considerations.

Low-grade Appendiceal Mucinous Neoplasm Presenting as Adnexal Mass: A Case Report

An appendiceal mucocele is a dilatation of the appendix and it is the result of benign or malignant diseases, which cause the obstruction of the appendix and the consequent accumulation of mucus secretion. The preoperative diagnosis is difficult due to non-specific clinical manifestations of the disease. We present a case of an 83-year-old female patient with a history of breast cancer that was referred to our hospital for an evaluation of a right adnexal mass discovered during her yearly follow-up. The patient underwent an exploratory laparotomy with a provisional diagnosis of a right adnexal mass. A perioperative, appendiceal mucocele was diagnosed. She underwent a formal appendectomy and histopathology of the specimen revealed a low-grade mucinous neoplasm. Appendiceal mucinous neoplasms represent a rare form of pathology among all appendectomy specimens. A preoperative diagnosis is difficult due to the lack of specific symptoms and it is often misdiagnosed as an adnexal mass. The perforation of the appendix and subsequent extravasation of its contents into the abdominal cavity may lead to pseudomyxoma peritonei, which has a very poor prognosis if not treated properly.