Endometriosis of the appendix. Report of twelve cases and review of the literature

Endometriosis of the appendix: prevalence, associated lesions, and proposal of pathogenetic hypotheses. A retrospective cohort study with prospectively collected data

OBJECTIVE

To assess the prevalence of endometriosis of the appendix and the association with other pelvic localizations of the disease and to provide pathogenesis hypotheses.

METHODS

Monocentric, observational, retrospective, cohort study. Patients undergoing laparoscopic endometriosis surgery in our tertiary referral center were consecutively enrolled. The prevalence of the different localizations of pelvic endometriosis including appendix involvement detected during surgery was collected. Included patients were divided into two groups based on the presence of appendiceal endometriosis. Women with a history of appendectomy were excluded.

MEASUREMENTS AND MAIN RESULTS

Four hundred-sixty patients were included for data analysis. The prevalence of appendiceal endometriosis was 2.8%. In patients affected by endometriosis of the appendix, concomitant ovarian and/or bladder endometriosis were more frequently encountered, with prevalence of 53.9% (vs 21.0% in non-appendiceal endometriosis group, p = 0.005) and 38.4% (vs 11.4%, p = 0.003), respectively. Isolated ovarian endometriosis was significantly associated to appendiceal disease compared to isolated uterosacral ligament (USL) endometriosis or USL and ovarian endometriosis combined (46.2% vs 15.4% vs 7.7%, p < 0.001). Poisson regression analysis revealed a 4.1-fold and 4.4-fold higher risk of ovarian and bladder endometriosis, respectively, and a 0.1-fold risk of concomitant USL endometriosis in patients with appendiceal involvement.

CONCLUSION

Involvement of the appendix is not uncommon among patients undergoing endometriosis surgery. Significant association was detected between appendiceal, ovarian, and bladder endometriosis that may be explained by disease dissemination coming from endometrioma fluid shedding. Given the prevalence of appendiceal involvement, counseling regarding the potential need for appendectomy during endometriosis surgery should be considered.

Appendiceal Endometriosis: A Comprehensive Review of the Literature

Objective: the purpose of this review was to evaluate the prevalence of appendiceal endometriosis and the safety of concomitant appendectomy in women with endometriosis or pelvic pain. Materials and Methods: We searched the electronic databases Medline (PubMed), Scopus, Embase, and Web of Science (WOS). The search was not subject to any limitation in terms of time or method. The primary research question was: what is the prevalence of appendiceal endometriosis? The secondary research question was: is it safe to perform appendectomy during surgery for endometriosis? Publications that reported data about appendiceal endometriosis or appendectomy in women with endometriosis were reviewed regarding the inclusion criteria. Results: We found 1418 records. After review and screening, we included 75 studies published between 1975 and 2021. With regard to the first question of the review, we found 65 eligible studies and divided these into the following two categories: (a) endometriosis of the appendix presenting as acute appendicitis, and (b) endometriosis of the appendix as an incidental finding in gynecological surgery. Forty-four case reports described appendiceal endometriosis in women who were admitted for the treatment of pain in the right-sided lower abdomen. Endometriosis of the appendix was observed in 2.67% (range, 0.36-23%) of women who were admitted due to acute appendicitis. In addition, appendiceal endometriosis was an incidental finding during gynecological surgery in 7.23% of cases (range, 1-44.3%). With regard to the second question of the review, which was the safety of appendectomy in women with endometriosis or pelvic pain, we found 11 eligible studies. Reviewed cases had no significant intraoperative or follow-up complications during the 12 weeks. Conclusion: Based on the reviewed studies, coincidental appendectomy appears reasonably safe and was associated with no complications in the cases reviewed for the present report.

Clinicopathologic findings in gynecologic proliferations of the appendix

Appendiceal endometriosis, endosalpingiosis, and decidual lesions have received little attention in the pathology literature, meaning their clinicopathologic features remain unclear. We identified 72 cases of appendiceal gynecologic proliferations with available slides. Clinical presentation was recorded when available, and histologic findings were correlated with clinical data. Cases included conventional endometriosis (51), endosalpingiosis (14), and decidual lesions (7). The patients with endosalpingiosis were significantly older (median 45 years) than those with endometriosis (median 34 years, P = .0085) or decidual lesions (median 31 years, P = .0088). Most endometriosis patients presented with known/suspected endometriosis (20/51, 39%), while acute appendicitis was the most common presentation for patients with endosalpingiosis (5/14, 36%) or a decidual lesion (5/7, 71%). Few patients presenting with appendicitis were ever diagnosed with extra-appendiceal disease. All 51 endometriosis cases showed both glands and stroma, and 18 (35%) had hemosiderin. One case progressed to endometrioid adenocarcinoma. Endosalpingiosis was an incidental finding in all cases, confined to the serosa in 4 and extending intramurally in 10. Four of the 7 patients with a decidual lesion were pregnant, and 2 others were taking oral contraceptives. The cases included florid decidualized endometriosis (5) and deciduosis (2). Two cases spread transmurally and effectively obliterated the appendix. Conventional appendiceal endometriosis can have several clinical presentations. Patients with it who present with acute appendicitis rarely develop it elsewhere. Appendiceal endosalpingiosis is rare and effectively incidental. Decidualized endometriosis may overtake the entire appendix.

Gastrointestinal and Urinary Tract Endometriosis: A Review on the Commonest Locations of Extrapelvic Endometriosis

Extrapelvic endometriosis is a rare entity that presents serious challenges to researchers and clinicians. Endometriotic lesions have been reported in every part of the female human body and in some instances in males. Organs that are close to the uterus are more often affected than distant locations. Extrapelvic endometriosis affects a slightly older population of women than pelvic endometriosis. This might lead to the assumption that it takes several years for pelvic endometriosis to "metastasize" outside the pelvis. All current theories of the pathophysiology of endometriosis apply to some extent to the different types of extrapelvic endometriosis. The gastrointestinal tract is the most common location of extrapelvic endometriosis with the urinary system being the second one. However, since sigmoid colon, rectum, and bladder are pelvic organs, extragenital pelvic endometriosis may be a more suitable definition for endometriotic implants related to these organs than extrapelvic endometriosis. The sigmoid colon is the most commonly involved, followed by the rectum, ileum, appendix, and caecum. Most lesions are confined in the serosal layer; however, deeper lesion can alter bowel function and cause symptoms. Bladder and ureteral involvement are the most common sites concerning the urinary system. Unfortunately, ureteral endometriosis is often asymptomatic leading to silent obstructive uropathy and renal failure. Surgical excision of the endometriotic tissue is the ideal treatment for all types of extrapelvic endometriosis. Adjunctive treatment might be useful in selected cases.

Rupture of appendiceal mucocele due to endometriosis: report of a case

We report a rare case of a mucocele of the appendix due to endometriosis which accidentally ruptured prior to surgery. A 56-year-old woman was referred to our institution for further evaluation of a cecal tumor. Colonoscopy showed a submucosal tumor at the appendiceal orifice in the cecum. Computed tomography and magnetic resonance imaging showed a well-circumscribed mass measuring 4 cm in diameter in the right lower quadrant. A preoperative diagnosis of a simple mucocele of the appendix was established. At laparotomy, a mucocele was identified in the right side of the abdomen; however, part of the mucocele had ruptured and yellow mucin was seen around the cecum. An ileocecal resection was performed. Histopathological examination was consistent with a mucocele of the appendix due to endometriosis. Cytology specimens from the yellow mucin showed few proliferating epithelial cells with a mild degree of cytological and architectural atypia. Mechanical pressure due to excess anteflexion during administration of epidural anesthesia may have contributed to the rupture of the mucocele. It is important to handle a mucocele of the appendix with great care to avoid rupture at the time of operation, including during the administration of epidural anesthesia.

Laparoscopic incidental appendectomy during laparoscopic surgery for ovarian endometrioma

OBJECTIVE

We sought to investigate the safety and efficacy of laparoscopic incidental appendectomy during laparoscopic surgery for endometrioma.

STUDY DESIGN

We conducted a retrospective study of 356 patients undergoing laparoscopic surgery for endometrioma with appendectomy (appendectomy group, n = 172) or not (nonappendectomy group, n = 184). Primary outcome measures were operating time, hemoglobin change, hospital stay, return of bowel activity, and any complications. The secondary outcome was appendiceal histopathology.

RESULTS

There were no statistical differences between groups in operating time, postoperative changes in hemoglobin concentration, hospital stay, return of bowel activity, or complication rate. Of the 172 resected appendices, 52 had histopathologically confirmed abnormal findings including appendiceal endometriosis in 16.

CONCLUSION

Incidental appendectomy at the time of laparoscopic surgery for endometrioma does not increase operative morbidity, and it has considerable diagnostic and preventive value. However, a large prospective randomized study is needed in the future to confirm this conclusion.

Endometriosis of the appendix: Report of three cases

Endometriosis of the appendix is an entity of extragonadal endometriosis. It commonly affects women in the childbearing age with a wide spectrum of clinical manifestations. Women can present with symptoms mimicking acute appendicitis or chronic pelvic pain. The surgical management varies from simple appendectomy to right hemicolectomy depending on the clinical findings. We report 3 cases of endometriosis of the appendix presenting with appendiceal intussusception. The surgical literature is reviewed and current surgical management is discussed.

Endometriosis at several sites, cyclic bowel symptoms, and the likelihood of the appendix being affected

In patients with endometriosis of the appendix, other sites are use to be affected by the disease, mainly bladder, rectosigmoid and retrocervical endometriosis. When these characteristics are present or if patients have more than three sites affected by endometriosis, the surgeon should evaluate the appendix carefully.

Endometriosis of the Vermiform Appendix Presenting as a Tumor

Endometriosis of the vermiform appendix is a rare condition. Most patients with this disease are asymptomatic or present as acute or chronic appendicitis. The author herein reports a case of appendiceal endometriosis presenting as a tumor at the appendiceal oriffice. A 41-year-old woman complained of chronic abdominal pain. A colon endoscopy showed a tumor in the appendiceal orifice. Two biopsies of the tumor showed no remarkable changes. Imaging modalities including CT and MRI also revealed an appendiceal tumor. Resection of appendix, cecum, ascending colon, terminal ileum, and 16 lymph nodes were performed under the clinical diagnosis of gastrointestinal stromal tumor. Grossly, a tumor measuring 3 x 3 x 3 cm was recognized in the appendiceral orifice. Histologically, the tumor was endometriosis consisting of islands of endometrial glands and stroma. Immunohistochemically, the lesion was positive for estrogen receptor and progesterone receptor, but it was negative for p53 protein and Ki-67 labeling was very low (0.5%). Similar endometriosis-like glands or Mullerian duct remnants were recognized in six out of 16 regional lymph nodes. The present case suggests that appendiceal endometriosis may present as a tumor.

A case of endometriosis of the appendix with adhesion to right ovarian cyst presenting as intussusception of a mucocele of the appendix

Endometriosis of the appendix is rare, and we present a case of endometriosis of the appendix with adhesion to right ovarian cyst presenting as intussusception of a mucocele of the appendix in a 35-year-old woman with no associated sign of endometriosis. Colonoscopy revealed intussusception-like change and mucosal defect in the mucosa at the orifice of the appendix. Abdominal computed tomography showed a low-density lesion, which seemed to be right ovarian cyst. However, as the appendix was located near this site, differentiation between ovarian cyst and mucocele of the appendix was difficult. Laparoscopic examination disclosed blue berry spots on the Douglas cul-de-sac and right ovarian cyst, and the appendix was atrophied and hardened and tightly adhered to the right ovary. Laparoscopic appendectomy and partial cecectomy was performed, and on pathologic examination, thickening and fibrosis of the muscle layer owing to endometriosis were judged to have caused intussusception-like changes.

Is incidental appendectomy necessary in women with ovarian endometrioma?

BACKGROUND

Several studies reported that pathology of the appendix is frequently detected alongside endometriosis, especially with chronic pelvic pain. Furthermore, ovarian endometriosis is a marker of more extensive pelvic and intestinal disease.

AIMS

To evaluate the feasibility and efficacy of incidental appendectomy in laparoscopic surgical treatment for ovarian endometrioma.

METHODS

One hundred and six women with ovarian endometrioma underwent laparoscopic surgery including laparoscopic appendectomy. Clinicopathological data were collected and analysed.

RESULTS

The main symptoms consisted of lower abdominal pain in 51 (48.1%) women, dysmenorrhoea in 23 (21.7%), left lower quadrant pain in 6 (5.7%), right lower quadrant pain in nine (8.5%), chronic pelvic pain in five (4.7%), and others in 12 (11.3%). Only three (3.3%) of the 106 women had abnormal findings on gross inspection during laparoscopic surgery: two women with endometriotic spots on the surface of their appendixes, and one with peri-appendiceal inflammation with severe adhesions. Of the 106 resected appendixes, 37 (34.9%) had histopathologically confirmed pathology including lymphoid hyperplasia in 12 (11.3%), endometriosis in 14 (13.2%), peri-appendicitis and serositis in five (4.7%), carcinoid tumour in three (2.8%), and others in three (2.8%).

CONCLUSIONS

In all surgical treatments for ovarian endometrioma, surgeons need to preoperatively inform the patients of the fact that appendiceal pathology including endometriosis is found frequently regardless of concurrent symptoms or gross finding of the appendix. Furthermore, surgeons should take into account the possibility of appendiceal pathology during operation.

Endometriosis of the vermiform appendix as an exceptional cause of acute perforated appendicitis during pregnancy

The incidence of appendicitis presenting during pregnancy is less than 1 in 1500. Most cases of endometriosis of the appendix are discovered as a result of incidental appendectomy. True perforated appendicitis in an endometriotic area has not been reported before. The authors report the case of a 28-year-old woman in her 27th week of pregnancy who underwent an appendicectomy for inflamed, perforated appendix with transmural endometriosis and accompanying decidual reaction.

Endometriosis of the appendix resulting in perforated appendicitis

Endometriosis is a relatively common disease among women of reproductive age. However, gastrointestinal endometriosis is rare and endometriosis of the appendix resulting in perforated appendicitis is even rarer. We experienced a case of endometriosis of the appendix manifesting as panperitonitis caused by perforation of the appendix. The patient was a 35-year-old woman who was hospitalized with an acute abdomen. She was diagnosed with panperitonitis and underwent urgent laparotomy. When perforation of the appendix was detected, appendectomy and intraperitoneal drainage were performed. Pathological examination revealed endometriosis extending from the muscularis propria to the subserosa, and a diagnosis of endometriosis of the appendix was made. We consider the relevant literature describing the mechanism by which endometriosis of the appendix occurs, and the association between endometriosis of the appendix and acute appendicitis.

Endometriosis and the appendix: a case series and comprehensive review of the literature

OBJECTIVE

To report the prevalence of appendiceal disease in women with chronic pelvic pain undergoing laparoscopy for possible endometriosis, summarize the literature, and more accurately estimate the prevalence of endometriosis of the appendix.

DESIGN

Prospective case series and literature review.

SETTING

Academic research institute.

PATIENT(S)

One hundred thirty-three patients with chronic pelvic pain and possible endometriosis undergoing laparoscopy.

INTERVENTION(S)

History, physical exam, and abdominopelvic laparoscopy. Endometriosis and adhesions were excised using selective Nd:YAG contact laser trabeculoplasty and pathologically evaluated. Only patients with visible abnormalities involving the appendix were treated via concurrent laparoscopic appendectomy.

MAIN OUTCOME MEASURE(S)

Appendiceal abnormalities at laparoscopy.

RESULT(S)

Of 133 patients, 13 had a previous appendectomy with unknown pathology. Of the remaining 120 patients, 109 reported right lower quadrant pain. Of this subgroup, six patients had appendiceal pathology: four with pathology-confirmed endometriosis, one with Crohn's disease suspected at laparoscopy, and one with chronic appendicitis. The prevalence of appendiceal endometriosis in patients with biopsy-proven endometriosis (n = 97) or with right lower quadrant pain (n = 109) was 4.1% and 3.7%, respectively. This rate was similar to the 2.8% prevalence confirmed by literature review in patients with endometriosis but was much higher than that reported in all patients (0.4%).

CONCLUSION(S)

Appendiceal endometriosis, while relatively uncommon in patients with endometriosis, is rare in the general population. In patients with right lower quadrant or pelvic pain, the appendix should be inspected for endometriosis and evidence of nongynecologic disease.

Miscellaneous conditions of the appendix

A variety of miscellaneous conditions affect the appendix, both as incidental findings and as causes of clinical signs and symptoms that often mimic appendicitis. Congenital abnormalities of the appendix are rare; the two most commonly reported are congenital absence and appendiceal duplication. Diverticular disease may be an incidental finding, but when inflamed, can be clinically confused with appendicitis. Endometriosis of the appendix, which usually occurs in the setting of generalized gastrointestinal endometriosis, often presents as acute appendicitis, but may present as intussusception, lower intestinal bleeding, and, particularly during pregnancy, perforation. Peritoneal endosalpingiosis often involves the appendiceal serosa and occasionally the wall but has no clinical manifestations in contrast to endometriosis. Vasculitis may be either isolated to the appendix or part of a systemic vasculitis, most often polyarteritis nodosa. Neural proliferations of the appendix include lesions associated with von Recklinghausen's disease, as well as mucosal and axial neuromas that are theorized to progress to fibrous obliteration of the appendix. Mesenchymal tumors of the appendix are most often of smooth muscle type, usually leiomyoma but rarely leiomyosarcoma; nonmyogenic neoplasms such as gastrointestinal stromal tumor, granular cell tumor, Kaposi's sarcoma, and miscellaneous other curiosities occur rarely. Lymphoma affects the appendix exceptionally; in children, Burkitt lymphoma is most common whereas in adults, large cell lymphomas and low grade B-cell lymphomas predominate. Secondary involvement of the appendix by leukemia has been reported. Secondary involvement of the appendix by carcinomas of the female genital tract, particularly ovary, and diverse other sites are in aggregate common but only rarely a clinical or pathological difficulty. Occasionally, however, appendiceal neoplasia that is secondary from another site may dominate the clinical picture and lead to potential pathologic misdiagnosis as primary appendiceal disease.

Laparoscopic appendectomy

STUDY OBJECTIVE

To evaluate the effectiveness of laparoscopic appendectomy in women with chronic pelvic pain and to identify histopathology of the appendix.

DESIGN

Retrospective review over 6.5 years (Canadian Task Force classification II-3).

SETTING

Laparoscopic center and community hospital.

PATIENTS

Three hundred seventeen women.

INTERVENTION

Laparoscopic appendectomy in conjunction with other procedures.

MEASUREMENTS AND MAIN RESULTS

Of 317 patients who underwent appendectomy, 14 (4.4%) had involvement of the appendix with endometriosis, 12 (3.78%) had early acute appendicitis, 4 (1.26%) had carcinoid tumors of the appendix, 2 (0.63%) had a large mucocele, and 1 (0.9%) each had Enterobius vermicularis infection, benign neuroma, and mucinous cystadenoma. Seventy-eight women (24.6%) had obliteration of the appendiceal lumen and 22 (6.93%) had entrapping fibrous adhesions. Thirty-two patients (10%) reported relief of chronic pelvic pain in the absence of other pathology just by having diagnostic laparoscopy with appendectomy.

CONCLUSION

The appendix is a key organ in the evaluation of undiagnosed chronic pelvic pain.

Endometriosis of the intestinal tract: a study of 44 cases of a disease that may cause diverse challenges in clinical and pathologic evaluation

Endometriosis of the intestinal tract may mimic a number of diseases both clinically and pathologically. The authors evaluated 44 cases of intestinal endometriosis in which endometriosis was the primary pathologic diagnosis, and evaluated them for a variety of gross and histologic changes. Cases with preneoplastic or neoplastic changes were excluded specifically because they were the subject of a previous study. The patients ranged in age from 28 to 56 years (mean age, 44 years), and presenting complaints included abdominal pain (n = 15), an abdominal mass (n = 12), obstruction (n = 8), rectal bleeding (n = 2), infertility (n = 3), diarrhea (n = 2), and increasing urinary frequency (n = 1). The clinical differential diagnoses included diverticulitis, appendicitis, Crohn's disease, tubo-ovarian abscess, irritable bowel syndrome, carcinoma, and lymphoma. Forty-two patients underwent resection of the diseased intestine and two patients underwent endoscopic biopsies. In 13 patients there were predominantly mural masses, which were multiple in two patients (mean size, 2.6 cm). In addition, 11 cases had luminal stenosis or strictures, six had mucosal polyps, four had submucosal masses that ulcerated the mucosa (sometimes simulating carcinoma), three had serosal adhesions, one had deep fissures in the mucosa, and one was associated with appendiceal intussusception. Involvement of the lamina propria or submucosa was identified in 29 cases (66%) and, of these, 19 had features of chronic injury including architectural distortion (n = 19), dense lymphoplasmacytic infiltrates (n = 7), pyloric metaplasia of the ileum (n = 1), and fissures (n = 1). Three cases had features of mucosal prolapse (7%), ischemic changes were seen in four (9%), and segmental acute colitis and ulceration were seen in four and six cases (9% and 13%) respectively. In 14 patients, endometriosis formed irregular congeries of glands involving the intestinal surface epithelium, mimicking adenomatous changes. Mural changes included marked concentric smooth muscle hyperplasia and hypertrophy, neuronal hypertrophy and hyperplasia, and fibrosis of the muscularis propria with serositis. Follow-up of 20 patients (range, 1-30 years; mean, 7.8 years) revealed that only two patients had recurrent symptoms. None of the patients developed inflammatory bowel disease. Endometriosis can involve the intestinal tract extensively, causing a variety of clinical symptoms, and can result in a spectrum of mucosal alterations. Because the endometriotic foci may be inaccessible to endoscopic biopsy or may not be sampled because of their focality, clinicians and pathologists should be aware of the potential of this condition to mimic other intestinal diseases.

Mucocele of the appendix secondary to endometriosis. Report of two cases, one with localized pseudomyxoma peritonei

This report documents 2 cases of obstructive mucocele of the appendix secondary to endometriosis of the appendix. In 1 case, the tip of the mucocele was ruptured and associated with localized pseudomyxoma peritonei. Mucoceles of the appendix usually are associated with hyperplastic or neoplastic mucosal proliferation; obstruction, particularly that due to endometriosis, is an infrequent cause. Occurrence of localized pseudomyxoma peritonei associated with appendiceal endometriosis and mucocele has not been reported previously.

Intussusception of a mucocele of the appendix secondary to an obstruction by endometriosis: report of a case

We treated a patient with a complete invagination of the cecum which contained a mucocele of the appendix secondary to an obstruction by endometriosis. Preoperatively, a barium enema showed a crab's claw-like area without filling in the oral side of the transverse colon. An emergency laparotomy was performed and revealed a mucocele of the appendix to have induced appendicecal invagination; however, no colonic invagination was observed. An appendicecal resection was thus done. Pathologically, the resected specimen was a mucosal hyperplasia with mucin-secreting lesions of the appendix. The theories regarding the pathogenesis of appendicecal mucocele are reviewed and discussed.

Different types of extragenital endometriosis: a review

Endometriotic growth may appear in any structure in the body. As well as affecting the internal genitalia, lesions are not uncommon in the bowel, urinary tract and thorax and reports of a number of cases at rarer sites have been published. This review is based on more than 1000 publications on the subject, that allows an overview of the appearance of the disease in different organs.

Endometriosis. An important condition in clinical gastroenterology

Endometriosis, a condition defined by the presence of ectopic endometrium, is a disorder of increasing incidence and a significant cause of gastroenterologic distress in young women. Although clinical manifestations vary considerably depending upon the anatomic extent of disease, characteristic abdominal complaints and typical physical findings continue to be associated with misdiagnosis and delayed recognition of gastrointestinal involvement. The authors of this paper review the medical literature concerning endometriosis of the digestive tract--emphasizing modes of presentation, risk factors, diagnostic testing, complications, and therapy. Greater familiarity with the disease and heightened awareness of its sequellae are needed and prerequisite to improved medical management.

Endometriosis of the vermiform appendix

The pathological findings and clinical aspects of 22 patients with endometriosis of the vermiform appendix are presented. The cases were found among 10,000 appendices examined from 1950 to 1981. During this period of 32 years, 800 cases of pelvic endometriosis were seen. In 10 patients no other locations of pelvic endometriosis were found.

Ileocecal endometriosis presenting with abdominal pain and gastrointestinal bleeding

A 26-year-old woman with enteric endometriosis presenting with cecocolic intussusception, a cecal mass on barium enema, and gastrointestinal hemorrhage is described. Laparotomy revealed cecocolic intussusception, ileocecal endometrial implants, and cecal mucosal ulceration presumed secondary to ischemia of the intussuscepted bowel. Histopathology showed serosal and subserosal endometrial implants without mucosal invasion. A review of the literature of endometrial bowel disease is presented.

Perforation of the appendix during pregnancy: a rare complication of endometriosis. Case report

Perforation of the appendix in a 23-year-old Nigerian Igbo woman during the 35th week of pregnancy is reported. In the perforated area, the wall of the appendix was replaced largely by decidualized endometriotic tissue.

Endometriosis of the appendix

The clinical and pathological features of 6 cases of appendiceal endometriosis are reported. The appendix alone was involved in 3. The findings have been compared with previously reported cases. One of the largest deposits caused intussusception but otherwise the microscopic size of deposits did not correlate with symptomatology. The diagnosis may be suspected when the abdominal pain does not shift from the peri-umbilical region to the right iliac fossa in the manner of classic appendicitis and when the symptoms begin during or are exacerbated by menstruation.

An unusual malformation of the vermiform appendix simulating endometriosis: a case report with discussion of differential diagnosis

A 48-year-old nulliparous woman with a long history of pelvic endometriosis underwent a gynecologic operation, and a swollen and indurated appendix was removed because of suspected endometriosis. Pathologic examination revealed no endometriosis, but examination of the distal appendix showed structural disorganization of its entire wall, with lack of proper differentiation of its normal coats and irregular overgrowth of fibroadipose, fibromuscular, and neural elements. Differential diagnoses, including endometriosis, carcinoid tumor and neurofibromatosis, are discussed.

Mucocele of the appendix secondary to obstruction by endometriosis

A mucocele of the appendix secondary to obstruction by endometriosis is reported and the relevant literature reviewed. The theories of the pathogenesis of appendiceal mucocele are reviewed and discussed. To our knowledge, no similar, well documented case has been reported.