Long-Term Outcomes after Surgery for Appendiceal Mucinous Tumours

Optimal Surgical Approaches for Incidentally Discovered Ruptured Mucinous Appendiceal Neoplasms

Mucinous neoplasms of the appendix, including low-grade appendiceal mucinous neoplasms (LAMNs), are rare but significant due to their potential for peritoneal dissemination. These tumors are often discovered incidentally during imaging or surgery for unrelated conditions. The presence of mucinous material in the peritoneum raises concern for pseudomyxoma peritonei, necessitating careful intraoperative and postoperative management. A 52-year-old male presented with testicular pain, leading to a diagnosis of seminoma. Staging computerized tomography (CT) revealed a dilated appendix with a surrounding fluid collection, suggestive of a ruptured mucocele. Exploratory laparotomy uncovered a large mucinous mass encasing the appendix, with mucinous deposits in the peritoneum. Final pathology confirmed an invasive mucinous adenocarcinoma, well-differentiated, arising in the background of a low-grade mucinous appendiceal neoplasm. The invasive component extended into the subserosa (pT3), while the LAMN component involved the serosa (pT4a). When mucin is found intraoperatively, surgeons should consider appendectomy with possible conversion to an open approach for thorough exploration. Emergency HIPEC is unnecessary; instead, it should be planned electively after complete cytoreduction. The prognosis depends on the extent of the disease and the success of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC).

Contrast-enhanced ultrasonography findings of LAMNs with peritoneal and splenic metastases: a case report and literature review

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare appendiceal tumors that are primarily diagnosed using computed tomography(CT) enhancement and magnetic resonance imaging (MRI). Herein, we report the sonographic features, especially for contrast-enhanced ultrasound (CEUS), of a 70-year-old female with an unusual LAMN metastasizing to the peritoneum and spleen. The patient had a right pelvic mass 2 days prior to presentation. Two-dimensional (2D) ultrasound revealed a mixed cystic-solid mass in the right lower abdomen and spleen parenchyma; CEUS showed heterogeneous enhancement in both areas, suspected to be a mucinous mass. CT enhancement and MRI findings revealed concurrent findings. Histopathologically, LAMN lesions were confirmed in the appendix, spleen, and peritoneum of the specimens obtained during exploratory laparoscopy. No recurrences were reported at three years postoperatively. LAMN lesions may metastasize to abdominal organs, and imaging examinations are essential for diagnosis. This study presents major ultrasonography and CEUS findings for the diagnosis of LAMNs.

Concomitant occurrence of appendiceal mucocele and ulcerative colitis: Case reports

Background

Appendiceal mucocele (AM) is a rare disease, manifested by accumulation of mucus in appendiceal lumen. The role of ulcerative colitis (UC) in the occurrence of appendiceal mucocele is not known. However, it is suggested that AM may be a presentation of colorectal cancer in IBD patients.

Case Presentation

Here, we presented 3 cases of concomitant AM and ulcerative colitis. The first patient was a 55-year-old woman with 2-year history of left sided UC; the second person was a 52-year-old woman with 12-year history of pan-UC; and the third patient was a 60-year-old man with 11-year history of pan-colitis. They were all referred due to indolent right lower quadrant abdominal pain. Imaging evaluations suggested the presence of appendiceal mucocele and therefore, they all went under operation. Pathologic evaluation reported AM of mucinous cyst adenoma type; low-grade appendiceal mucinous neoplasm of appendix with intact serosa; and cyst-adenoma type AM for the three above-mentioned patients, respectively.

Conclusion

Although concomitant occurrence of AM and ulcerative colitis is rare, regarding the potential of neoplastic changes in AM, physicians must keep in mind the diagnosis of AM in UC patients with non-specific abdominal RLQ pain or bulged appendiceal orifice during colonoscopy.

Appendiceal tumors in patients undergoing primary surgery for mucinous ovarian tumors in a tertiary hospital, in Southern Thailand

OBJECTIVE

To evaluate the prevalence of appendiceal tumors in patients diagnosed with mucinous ovarian tumors and to determine factors associated with coexisting appendiceal tumors.

MATERIALS AND METHODS

Retrospective review of all patients who were diagnosed with mucinous ovarian tumors and underwent an appendectomy during surgery between January 2002 and June 2017 was performed. Univariate and multivariate logistic regression analyses were used to identify risk factors for coexisting appendiceal tumors.

RESULTS

A total of 303 patients with mucinous ovarian tumors who underwent appendectomy were identified, including 77 (25.4%) mucinous cystadenoma and 226 (74.6%) mucinous borderline tumor or carcinoma. Twenty-one (6.9%) had coexisting appendiceal tumors including 8 that were primary appendiceal mucinous adenocarcinomas, 6 low-grade appendiceal mucinous neoplasms, 6 secondary appendiceal metastasis from the ovary, and one hyperplastic polyp. None of mucinous cystadenoma had coexisting appendiceal tumors. Multivariate analysis revealed advanced age ≥50 years, previous rupture of ovarian tumors, abdominal extension of tumors, and grossly abnormal appendix were independent factors for coexisting appendiceal tumors.

CONCLUSION

Prevalence of coexisting appendiceal tumors in mucinous ovarian tumors was not uncommon. The risk factors were grossly abnormal appendix, abdominal extension of tumor, previous rupture of ovarian tumors, and advanced age.

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.

OUP accepted manuscript

Primary neoplasm of the appendix is often diagnosed incidentally after an appendectomy. Low-grade appendiceal mucinous neoplasms (LAMNs) make up a small portion of these neoplasms. We present a rare case of a patient with a slow-growing LAMN causing urinary retention and constipation. The mass was initially found incidentally 25 years prior, but the patient declined further workup since he was asymptomatic at that time. The patient experienced progressively worsening abdominal discomfort related to urinary retention and difficulty in evacuating his bowels. Imaging identified a large abdominal mass (19.3 × 8.7 × 13.5 cm). The mass was surgically resected. Pathology was consistent with a LAMN. In general, an incidental finding of an abdominal mass should be further investigated regardless of symptomology. Patients should be educated about the potential of malignancy and the need for a major abdominal surgery in the future if they choose not to have a mass further evaluated.

Low-Grade Appendiceal Mucinous Neoplasm (LAMN) Primarily Diagnosed as an Ovarian Mucinous Tumor

Background

Low-grade appendiceal mucinous neoplasms (LAMN) are detected in 0.7 to 1.7% of all appendicectomies. The diagnosis can be challenging, particularly in female patients where the differential diagnosis of primary appendiceal and ovarian mucinous neoplasms is unclear. Case Presentation. A 71-year-old female was referred to our tertiary hospital with the working diagnosis of a right ovarian cystic tumor. The lesion was identified through a transvaginal ultrasound performed for vague lower abdominal pain symptoms. CT scan confirmed these findings. Intraoperatively, an appendiceal mucocele was identified and a right hemicolectomy was performed. The histopathology examination revealed a LAMN. Six months later, the patient remains disease-free. A close biannual oncological follow-up has been suggested.

Conclusion

This case underlines the difficulty in determining the origin of mucinous neoplasms of the right pelvic area. Mucocele of the appendix should be considered in the differential diagnosis of a mass in the right iliac fossa.

Survival of patients with resected primary colorectal mucinous adenocarcinoma: A competing risk nomogram analysis

The aim of the present study was to use a competing risk model to analyze the prognostic value of mucinous adenocarcinoma (MAC) in patients with colorectal cancer (CRC). An additional aim was to construct nomograms for estimating the 3- and 5-year overall survival (OS) and cancer specific survival (CSS) rates of patients with primary CRC with MAC. The data were extracted from the Surveillance, Epidemiology, and End Results database, and a Multivariate Cox model and competing risk model were applied to assess the OS and CSS. Cox-based and competing risk-based nomograms were constructed and internally validated by discrimination and calibration, using the bootstrapping method with 1,000 times replicates. A total of 13,035 MAC and 61,958 non-mucinous adenocarcinoma (NMAC) CRC patients were enrolled in the present study. Compared with NMAC, MAC patients had a poorer OS and CSS time in the overall population, and in subgroups that comprised metastatic, non-metastatic, male, site of sigmoid colon, rectosigmoid junction and rectal CRC cases (HR>1; P<0.05). The Cox and competing risk-based nomograms showed effective discrimination and calibration. In conclusion, MAC was associated with poor OS and CSS in patients with CRC of the distal colon and rectum. The nomograms of primary CRC patients with MAC may aid the identification of individual patients with a high risk of overall mortality and cancer-associated mortality within 3 or 5 years.