Mucinous appendiceal neoplasms: Incidence, diagnosis and surgical treatment

Incidental appendiceal neoplasms: Single-centre results

BACKGROUND

Histopathological examination of appendectomy specimens may reveal malignancies. Based on these results, either appendectomy is sufficient or sometimes a further treatment protocol can be needed. In this study, malignancy-diagnosed cases on appendectomy specimen were examined.

METHODS

Patients who underwent appendectomy between January 2013 and December 2018 with a pre-diagnosis of acute appendicitis were evaluated retrospectively and those cases with malignancy were included in the study. Patients' age, sex, tumor type, tumor diameter, tumor grade, tumor localization, surgical margin, Ki-67 index, state of lymphovascular invasion, state of peri-neural invasion, and follow-up period duration were recorded.

RESULTS

On examination of 2336 appendectomy specimens, 16 patients (0.7%) were found to have neuroendocrine tumors (NET), 11 patients (0.5%) were found to have low-grade mucinous neoplasm (LAMN), and five patients (0.2%) were found to have primary appendix carcinomas. Appendix tumors usually present with acute appendicitis symptoms. Despite re-operation with right hemicolectomy (RHC) being required in the treatment of adenocarcinoma cases, appendectomy provides adequate treatment in most cases with NET and LAMN. With these tumors, which usually have a benign prognosis, it is important to perform the necessary screening in the postoperative period and not to interrupt follow-up.

Incidence of appendiceal neoplasms in appendectomy patients

BACKGROUND

Non-operative management has been suggested as a therapy for uncomplicated appendicitis. Notwithstanding, the risk of missing an appendiceal tumor must be considered, being the surgical piece crucial to rule out neoplasms. Therefore, we aim to determine the incidence of appendiceal neoplasms in patients with acute appendicitis, tumor types and the importance of the anatomopathological study of the surgical piece.

STUDY DESIGN

Retrospective study in which we described patients who underwent emergent appendectomy with histopathological findings of appendiceal neoplasms from January 2012 to September 2018. Descriptive analysis included demographic variables, diagnostic methods, and surgical techniques.

RESULTS

2993 patients diagnosed with acute appendicitis who underwent an emergency appendectomy. 64 neoplasms of the appendix were found with an incidence of 2,14%. 67.2% were women, the mean age was 46,4 years (± 19.5). The most frequent appendiceal neoplasms were neuroendocrine tumors (42,2%), followed by appendiceal mucinous neoplasms (35,9%), sessile serrated adenomas (18,8%), and adenocarcinomas (3,1%). In 89,1% of the cases, acute appendicitis was determined by imaging, and 14% of cases were suspected intraoperatively. Appendectomy was performed in 78,1% without additional procedures.

CONCLUSIONS

Appendiceal tumors are rare and must be ruled out in patients with suspected acute appendicitis. The incidence of incidental neoplasms is higher in this study than in the previously reported series. This information must be included in decision-making when considering treatment options for acute appendicitis.

Incidence and outcomes of delayed presentation and surgery in peritoneal surface malignancies

Background

Peritoneal surface malignancies (PSM) present insidiously and often pose diagnostic challenges. There is a paucity of literature quantifying the frequency and extent of therapeutic delays in PSM and its impact on oncological outcomes.

Methods

A review of a prospectively maintained registry of PSM patients undergoing Cytoreductive Surgery and Hyperthermic Intra-peritoneal Chemotherapy (CRS-HIPEC) was conducted. Causes for treatment delays were identified. We evaluate the impact of delayed presentation and treatment delays on oncological outcomes using Cox proportional hazards models.

Results

319 patients underwent CRS-HIPEC over a 6-years duration. 58 patients were eventually included in this study. Mean duration between symptom onset and CRS-HIPEC was 186.0 ± 37.1 days (range 18-1494 days) and mean duration of between patient-reported symptom onset and initial presentation was 56.7 ± 16.8 days. Delayed presentation (> 60 days between symptom onset and presentation) was seen in 20.7% (n=12) of patients and 50.0% (n=29) experienced a significant treatment delay of > 90 days between 1^st presentation and CRS-HIPEC. Common causes for treatment delays were healthcare provider-related i.e. delayed or inappropriate referrals (43.1%) and delayed presentation to care (31.0%). Delayed presentation was a significantly associated with poorer disease free survival (DFS) (HR 4.67, 95% CI 1.11-19.69, p=0.036).

Conclusion

Delayed presentation and treatment delays are common and may have an impact on oncological outcomes. There is an urgent need to improve patient education and streamline healthcare delivery processes in the management of PSM.

The Appendix: A Rare Case of an Appendiceal Collision Tumor

Appendicitis is a common cause of right lower quadrant pain. However, appropriate diagnostic evaluation and a high clinical suspicion can reveal alternative etiologies that are not so commonly encountered. In this report, we present a rare case of an appendiceal collision tumor involving two distinct neoplasms as the source of the patient's pain and describe how thoughtful clinical maneuvering led to its diagnosis and treatment.

Appendectomy Should Be Performed During Minimally Invasive Surgery for Endometriosis

Objectives:

To determine the prevalence of appendiceal histopathology in patients with confirmed endometriosis following minimally invasive surgery (MIS) for endometriosis. To determine whether pre-operative symptoms, age, intra-operative appendiceal appearance, or endometrioma laterality were associated with appendix histopathology in patients with suspected endometriosis.

Methods:

One hundred thirty-five patients ages 16–52 with suspected endometriosis undergoing MIS for endometriosis with concomitant appendectomy at two metropolitan academic hospitals from January 1, 2012 to June 30, 2017 were included in this retrospective chart-review study. Medical records were reviewed for pre-operative symptoms, age, intraoperative appendix appearance, appendix histopathology, histopathologically-confirmed endometriosis, and endometriomas.

Results:

In patients with confirmed endometriosis, the prevalence of all appendiceal histopathology was 25%, which included appendiceal endometriosis (18%), appendiceal tumors (2%), and inflammation (5%). Dyspareunia was the only pre-operative symptom significantly associated with appendiceal histopathology (p = 0.04). The presence of a right endometrioma was associated with appendiceal histopathology (p = 0.009). Additionally, appendiceal histopathology was not significantly associated with age nor intra-operative appendiceal characteristics.

Conclusion:

This manuscript adds to the limited pool of studies regarding appendiceal histopathology and appendiceal tumors in patients with suspected and confirmed endometriosis. On the basis of the high rate of histopathological appendices found in this population; the lack of association with possible diagnostic factors such as age, most pre-operative symptoms, and intra-operative appendiceal characteristics; and the relatively low risks of concomitant appendectomy, we suggest that surgeons consider concomitant appendectomies at the time of MIS for endometriosis.

Low-grade mucinous appendiceal neoplasm mimicking an ovarian lesion: A case report and review of literature

BACKGROUND

Appendiceal tumors are rare lesions that may not be easily differentiated from primary ovarian lesions preoperatively, despite the use of advanced diagnostic methods by experienced clinicians.

CASE SUMMARY

A 59-year-old G2P2 woman, with chronic pelvic pain, underwent a pelvic ultrasound that revealed an adnexal mass measuring 58 mm × 34 mm × 36 mm, with irregular borders, heterogeneous echogenicity, no color Doppler vascularization and without acoustic shadowing. Normal ovarian tissue was visualized in contact with the lesion, and it was impossible to separate the lesion from the ovary by applying pressure with the ultrasound probe. Ascites, peritoneal metastases or other alterations were not observed. With the international ovarian tumor analysis ADNEX model, the lesion was classified as a malignant tumor (the risk of malignancy was 27.1%, corresponding to Ovarian-Adnexal Reporting Data System category 4). Magnetic resonance imaging confirmed the presence of a right adnexal mass, apparently an ovarian tumor measuring 65 mm × 35 mm, without signs of invasive or metastatic disease. During explorative laparotomy, normal morphology of the internal reproductive organs was noted. A solid mobile lesion involved the entire appendix. Appendectomy was performed. Inspection of the abdominal cavity revealed no signs of malignant dissemination. Histopathologically, the appendiceal lesion corresponded to a completely resected low-grade mucinous appendiceal neoplasm (LAMN).

CONCLUSION

The appropriate treatment and team of specialists who should provide health care to patients with seemingly adnexal lesions depend on the nature (benign vs malignant) and origin (gynecological vs nongynecological) of the lesion. Radiologists, gynecologists and other pelvic surgeons should be familiar with the imaging signs of LAMN whose clinical presentation is silent or nonspecific. The assistance of a consultant specializing in intestinal tumors is important support that gynecological surgeons can receive during the operation to offer the patient with intestinal pathology an optimal intervention.

Nomenclature of appendiceal mucinous lesions according to the 2019 WHO Classification of Tumors of the Digestive System

BACKGROUND/AIMS

To analysis the appendiceal mucinous lesions according to the World Health Organization (WHO) 2019 classification of tumors of the digestive system (non-neuroendocrine tumors of the appendix vermiformis)

MATERIALS AND METHODS

Clinical and histopathological data of 37 patients with histopathologically proven appendiceal mucinous lesion from January 2010 to May 2019 were evaluated retrospectively. Pathology slides were re-evaluated by two pathologists according to the WHO 2019 classification of tumors of the digestive system.

RESULTS

Totally 37 patients (male:19 female: 18) aged 23 to 93 years were analyzed. Majority of the patients (75.7 %) had underwent appendectomy due to preliminary diagnosis of acute appendicitis (n=22) or periappendiceal tumoral lesions (n=9), the others (n=9) underwent incidental appendectomy. Whereas acute appendicitis was histopathologically diagnosed in 16 (43.2%) patients, perforation was diagnosed in 12 (32.4%) patients (perforation without appendicitis=3, perforation with appendicitis=6). According to the initial, pathology reports were prepared as follows: mucocele (n=10), mucinous cystadenoma (n=9), low-grade mucinous neoplasm (n=6), mucinous adenocarcinoma (n=5), mucosal hyperplasia (n=5), hyperplastic polyp (n=1), adenomatous polyp (n=1). On the basis of the WHO 2019 classification, pathology reports were prepared as follows: low-grade mucinous neoplasm (n=17), simple retention cysts (n=6), hyperplastic polyp (n=6), mucinous adenocarcinoma (n=5), ruptured appendiceal diverticula (n=2), sessile serrated lesion (n=1).

CONCLUSION

The term of appendiceal mucinous lesion, which is recently introduced into medical literature is suitable to distinguish between lesions with and without malignancy potential. The WHO 2019 classification system has been an important step in simplifying the classification of non- neuroendocrine tumors of the appendix vermiformis.

Impact of cytoreductive surgery on outcomes of metastatic appendiceal carcinoma: a real-world, population-based study

Aim: To evaluate the impact of cytoreductive surgery on the outcomes of patients with metastatic appendiceal carcinoma. Methods: Surveillance, Epidemiology and End Results (SEER) database was accessed and patients with metastatic appendiceal carcinoma diagnosed (2010-2015) were reviewed. Kaplan-Meier survival estimates/log-rank testing were then used to assess overall survival outcomes according to cytoreductive surgery. Multivariable Cox regression analysis was then used to evaluate factors affecting cancer-specific survival. Factors included in this model were age, race, sex, stage and histology and cytoreductive surgery. Results: A total of 1339 patients with metastatic appendiceal carcinoma were included in the current study. Using Kaplan-Meier survival estimates to evaluate overall survival, patients with surgery for metastatic disease have better overall survival compared with patients without surgery for metastatic disease (p < 0.001). Stratifying survival analysis according to histology, the overall survival benefit from surgery for the metastases seems to be limited to patients with mucinous adenocarcinoma (p = 0.002) rather than patients with nonmucinous adenocarcinoma (p = 0.401). Multivariable Cox regression analysis was then conducted to evaluate factors predicting cancer-specific survival. The following factors were associated with worse cancer-specific survival: African-American race (hazard ratio [HR]: 1.356; 95% CI: 1.036-1.774; p = 0.026), more advanced stage (HR: 3.910; 95% CI: 2.735-5.588; p < 0.001), nonmucinous adenocarcinoma (HR for signet ring carcinoma vs mucinous adenocarcinoma: 2.119; 95% CI: 1.674-2.683; p < 0.001) and no surgical resection of metastatic disease (HR: 1.273; 95% CI: 1.067-1.519; p < 0.001). Conclusion: The current study suggests that among patients with metastatic appendiceal carcinoma, surgical cytoreduction of metastatic disease is associated with improved outcomes for patients with mucinous adenocarcinoma but not in patients with nonmucinous adenocarcinoma.

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.