Intussusception of the appendix by a villous adenoma

Intussusception of the Appendix and Ileum Endometriosis: A Case Report

BACKGROUND

Intussusception of the appendix is a very rare condition. It may clinically mimic acute or chronic abdominal diseases or can be asymptomatic.

CASE REPORT

This paper describes our experience with intussusception of the appendix. We report a case of a female with appendiceal intussusception and ileum endometriosis.

CONCLUSION

It is important to know about such a rare condition in order to avoid mistaking it with other abdominal diseases. However, diagnosis is rarely made preoperatively.

Mucinous epithelial neoplasms of the appendix and pseudomyxoma peritonei

The classification of appendiceal mucinous neoplasms has been controversial, largely focused on a particular subset of low-grade mucinous tumors that, despite their innocuous appearance, can disseminate to the peritoneal cavity as pseudomyxoma peritonei (PMP). Recent WHO classification of these tumors as low-grade appendiceal mucinous neoplasms acknowledges their unique morphologic appearance and biologic behavior. Still, debate about the use of this term and its parameters continues to impede the adoption of consensus classification for appendiceal mucinous neoplasms. The classification of PMP has also been the subject of debate, with international authorities advocating for the use of malignant terminology to describe all grades of PMP, even though some authorities consider low-grade PMP to be dissemination of adenomatous epithelium in the peritoneum. Recent data also emphasize the importance of histologic grade of the peritoneal tumors in defining prognosis of these patients.

Primary epithelial neoplasms and other epithelial lesions of the appendix (excluding carcinoid tumors)

Epithelial tumors of the appendix range from low-grade mucosal-based tumors which, when confined to the appendix, have an excellent prognosis but, once outside the appendix, have a fair prognosis and often a prolonged disease course, to high grade invasive carcinomas that are rapidly fatal. Low grade mucinous neoplasms may rupture and spread to the peritoneum as pseudomyxoma peritonei, and the nomenclature of these tumors has been the subject of considerable disagreement among pathologists; the designation "low grade appendiceal mucinous neoplasm" has recently been proposed for reasons discussed herein. Demonstrating rupture of these neoplasms may require particularly diligent gross and microscopic evaluation as the rupture site often heals over leaving only subtle evidence of its presence. Invasive adenocarcinomas are often mucinous and may also spread to the peritoneum. Against this backdrop, the clinical and pathologic features of low grade appendiceal mucinous neoplasms and mucinous adenocarcinomas, as well as other types such as typical colorectal type and signet-ring cell type, are reviewed. In addition, emerging entities, serrated polyps and serrated adenomas, whose significance is only beginning to be understood, are considered. Retention cysts, hyperplastic polyps, and diffuse mucosal hyperplasia, although not necessarily neoplastic, are reviewed here as they may enter into the differential diagnosis of appendiceal mucinous neoplasms.