Neuroendocrine appendiceal tumor and endometriosis of the appendix: a case report

Abstract

Introduction Endometriosis of the appendix is very uncommon, accounting for only about 1% of all cases of endometriosis. However, endometriosis is found in the appendix in approximately 8–13% of patients with deep infiltrating endometriosis and is particularly common in patients with severe forms of deep infiltrating endometriosis. Neuroendocrine tumors are the most common neoplasms of the appendix and may be misdiagnosed when there are multiple endometriosis lesions in the pelvis. Case presentation We describe a case of a Caucasian patient with deep infiltrating endometriosis with rectal involvement, retrocervical lesions, and a right ovarian endometrioma with no suspected lesions in the appendix. She underwent laparoscopy and, after a systematic intraoperative evaluation, suspected involvement of the appendix was observed. The patient underwent ovarian cystectomy, excision of the pelvic endometriosis lesions, appendectomy, and anterior stapler discoid resection. Histopathological analysis of the appendix revealed endometriosis and a well-differentiated neuroendocrine carcinoma at the appendix tip. Discussion Our patient’s case emphasizes the need to approach these lesions carefully and strengthens the indication for appendectomy when the appendix is affected in the setting of endometriosis. Despite the more likely diagnosis of appendiceal endometriosis, neuroendocrine tumors cannot be ruled out by imaging examinations, and both conditions can occur in the same patient.

Postoperative Complications and Stoma Rates After Laparoscopic Resection of Deep Infiltrating Endometriosis with Bowel Involvement

“…The analysis of the appendix of one patient revealed a well-differentiated neuroendocrine carcinoma at the appendix tip. 14 The ileum was involved in 6% of cases. Only 2 patients (1.3%) did not have rectosigmoid involvement and underwent laparoscopy: one due to isolated small bowel (ileal) involvement and the other due to ileal and appendix involvement.…”

Analysis of surgical treatment of appendix neuroendocrine neoplasms—17 years of single-center experience

“…To date, the etiology of neuroendocrine carcinoma of the appendix remains unclear. Recent reports have indicated that endometriosis may be related to the occurrence of neuroendocrine carcinoma of the appendix [ 24 , 25 ]. Virgine C et al described five children with neuroendocrine tumors of the appendix (NET) associated with parasitic intestinal infections and discussed the possibility of inflammation leading to canceration.…”

Diagnosis of Appendiceal Neuroendocrine Tumors Following Incidental Appendectomy During Benign Gynecologic Laparoscopic Surgeries: A Case Series

“…Endometriosis implants have been identified on the appendix during a histopathologic review, and studies have suggested that the appendix may contribute to chronic pelvic pain [ 4 , 5 ]. Coexisting endometriosis and appendiceal neuroendocrine tumors have also been identified during gynecologic surgeries [ 6 , 7 ]. One systematic review identified that the rates of ANETs are the same in endometriosis patients as in the general population, which suggests that endometriosis is not a risk factor for ANETs [ 8 ].…”