An unusual cause of acute appendicitis: Appendiceal endometriosis

When the Appendix Takes a Detour: A Rare Case of the Appendix Intussuscepting Into the Caecum Mimicking an Appendiceal Mucocele

Acute appendicitis is a common condition, whereby accurate diagnosis relies on multiple modalities in conjunction with a thorough history and clinical examination. Imaging, particularly computed tomography (CT), is highly sensitive in reliably determining the position of the appendix. It is not unusual for appendicitis to present in atypical ways or be masked as other intra-abdominal conditions, complicating the diagnosis. This report discusses a rare case of intussusception of the appendix into the caecum, with a histopathological specimen later proving the intraoperative specimen as endometrial tissue, highlighting an uncommon presentation. We report the case of a 51-year-old woman who experienced worsening abdominal pain, nausea, and early satiety over several months. Initial evaluation revealed microcytic anaemia and a smoking history of 25 pack-years. Imaging strongly suggested an appendiceal mucocele. A colonoscopy revealed a large caecal polyp originating from within the appendiceal orifice. A multidisciplinary team discussion recommended performing a diagnostic laparoscopy to further guide management. While conducting the laparoscopic surgery, a lump on the taenia coli obscured the view of the appendix, necessitating a partial caecectomy. Postoperative examination of the specimen confirmed intussusception of the appendix into the caecum, later verified by a pathologist to be appendiceal endometriosis. This case highlights the significant diagnostic challenges linked to adult intussusception. Although CT scans and colonoscopy are vital in preoperative assessments, correctly identifying the underlying condition can be difficult. The laparoscopic approach has shown both safety and effectiveness in diagnosis and treatment. Prompt surgical intervention is crucial for resolving intussusception and treating appendicitis to prevent serious complications.

Appendiceal Endometriosis: A Rare Case of Endometriosis Mimicking Acute Appendicitis

Appendiceal endometriosis (AE) is a rare type of extragonadal endometriosis with symptoms of right lower abdominal pain, nausea, and vomiting that mimic acute appendicitis. The gold standard for a definitive diagnosis is a histopathological examination of the excised appendix. We report a case of AE in a 39-year-old female patient, G10P3, with a past surgical history of cholecystectomy, seven dilation and curettage procedures, and one prior cesarean section presenting with a right lower quadrant pain with intermittent non-bloody diarrhea, nausea, and vomiting that is not exacerbated by movement. The patient was mildly tachycardic with otherwise stable vitals and no leukocytosis. The beta-hCG test was negative with a CT-confirmed Mirena® intrauterine contraceptive device (IUD) (Bayer AG, Leverkusen, Germany) placement. The patient denied heavy bleeding or vaginal discharge. The CT scan of the abdomen and pelvis with oral contrast demonstrated findings suggestive of appendicitis, leading to a subsequent laparoscopic appendectomy. The resected specimen showed histopathology features of endometriosis, confirming AE. AE poses diagnostic challenges due to its nonspecific imaging findings along with variable symptomatic presentations. The recommended management of AE is an appendectomy with a gynecological follow-up postoperatively. AE is a rare condition that can masquerade as acute appendicitis in female patients. We highlight the importance of including AE in the differential diagnosis of female patients presenting with lower abdominal pain.

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.

Archimetrosis: the evolution of a disease and its extant presentation : Pathogenesis and pathophysiology of archimetrosis (uterine adenomyosis and endometriosis)

PURPOSE

This article presents a novel concept of the evolution and, thus, the pathogenesis of uterine adenomyosis as well as peritoneal and peripheral endometriosis. Presently, no unifying denomination of this nosological entity exists.

METHODS

An extensive search of the literature on primate evolution was performed. This included comparative functional morphology with special focus on the evolution of the birthing process that fundamentally differs between the haplorrhine primates and most of the other eutherian mammals. The data were correlated with the results of own research on the pathophysiology of human archimetrosis and with the extant presentation of the disease.

RESULTS

The term Archimetrosis is suggested as a denomination of the nosological entity. Archimetrosis occurs in human females and also in subhuman primates. There are common features in the reproductive process of haplorrhine primates such as spontaneous ovulation and corpus luteum formation, spontaneous decidualization and menstruation. These have fused Müllerian ducts resulting in a uterus simplex. Following a usually singleton pregnancy, the fetus is delivered in the skull position. Some of these features are shared by other mammals, but not in that simultaneous fashion. In haplorrhine primates, with the stratum vasculare, a new myometrial layer has evolved during the time of the Cretaceous-Terrestrial Revolution (KTR) that subserves expulsion of the conceptus and externalization of menstrual debris in non-conceptive cycles. Hypercontractility of this layer has evolved as an advantage with respect to the survival of the mother and the birth of a living child during delivery and may be experienced as primary dysmenorrhea during menstruation. It may result in tissue injury by the sheer power of the contractions and possibly by the associated uterine ischemia. Moreover, the lesions at extra-uterine sites appear to be maintained by biomechanical stress.

CONCLUSIONS

Since the pathogenesis of archimetrosis is connected with the evolution of the stratum vasculare, tissue injury and repair (TIAR) turns out to be the most parsimonious explanation for the development of the disease based on clinical, experimental and evolutionary evidence. Furthermore, a careful analysis of the published clinical data suggests that, in the risk population with uterine hypercontractility, the disease develops with a yet to be defined latency phase after the onset of the biomechanical injury. This opens a new avenue of prevention of the disease in potentially affected women that we consider to be primarily highly fertile.

Appendiceal Endometriosis with Intestinal Metaplasia Mimicking Appendiceal Mucinous Neoplasm - A Case Report and a Concise Review for the Practicing Pathologist

Appendiceal endometriosis is a rare entity and, when accompanied by intestinal metaplasia, represents a challenging differential diagnosis with low-grade appendiceal mucinous neoplasm (LAMN). We present the case of a 47 years-old woman, with multiple surgical interventions for endometriosis, with persistent symptoms despite chronic hormonal treatment, with imaging showing stage IV endometriosis. Hence, en bloc low rectum resection with total hysterectomy and bilateral adnexectomy was performed, followed by appendectomy. Unexpectedly, despite the gross normal macroscopic appearance of the appendix, microscopy showed multiple endometriosis foci, consisting of endometrial glands embedded in varying amounts of endometrial stroma. As some of these glands were bordered by mucinous-type epithelium containing intestinal cells, Goblet cells, Paneth cells in addition to the presence of mucus-filled microcysts, immunohistochemistry (IHC) was performed in order to differentiate between intestinal-metaplasia and LAMN. IHC showed positivity of the endometrial epithelium for KRT7, estrogen receptor (ER) and progesterone receptor (PR). Both the appendiceal mucosa and the intestinal-type metaplastic epithelium of the glandular structures were positive for KRT20. Additionally, the endometrial stroma enclosing endometrial glands, as well as the stroma surrounding mucinous-type metaplastic epithelium, were positive for CD10, ER and PR. This patient's case draws attention to the rare occurrence of appendiceal endometriosis and the uncommon intestinal metaplasia, which can easily mimic LAMN, emphasizing the paramount importance of the differential diagnosis with this type of neoplasia.

Extragenital Endometriosis in the Differential Diagnosis of Non- Gynecological Diseases

BACKGROUND

Endometriosis is a chronic, benign disease that affects approximately 10% of women of childbearing age. Its characteristic clinical features are dysmenorrhea, dyschezia, dysuria, dyspareunia, and infertility. The manifestations of extragenital endometriosis (EE) are a diagnostic challenge, as this disease can mimic other diseases due to its unusual location with infiltration of various organs and corresponding symptoms.

METHODS

This review is based on publications retrieved by a selective search of the literature on the commonest extragenital sites of endometriosis, including the relevant current guideline.

RESULTS

Current evidence on the treatment of extragenital endometriosis consists largely of cohort studies and cross-sectional studies. The treatment is either surgical and/or conservative (e.g., hormonal therapy). Gastrointestinal endometriosis is the most common form of EE, affecting the rectum and sigmoid colon in nearly 90% of cases and typically presenting with dyschezia. Urogenital endometriosis is the second most common form of EE. It affects the bladder in more than 85% of cases and may present with dysuria, hematuria, or irritable bladder syndrome. The diaphragm is the most common site of thoracic endometri - osis, potentially presenting with period-associated shoulder pain or catamenial pneumothorax. Endometriosis affecting a nerve often presents with sciatica. In abdominal wall endometriosis, painful nodules arise in scars from prior abdominal surgery.

CONCLUSION

There is, as yet, no causally directed treatment for chronic endometriosis. The treatment is decided upon individually in discussion with the patient, in consideration of risk factors and after assessment of the benefits and risks. Timely diagnosis is essential.

Incidental appendiceal mass as the only manifestation of endometriosis

Appendiceal endometriosis is a rare condition that remains difficult to diagnose preoperatively. Herein, we present a case of appendiceal endometriosis presenting as a neuroendocrine tumor. A 34-year-old Caucasian woman was found to have an appendiceal mass with a small fluid collection on routine transvaginal ultrasound. The patient denied any symptoms. Features were consistent with those of a neuroendocrine tumour of the appendix. Laparoscopic appendectomy followed by histopathology revealed endometriosis with negative cytology for malignant cells. Preoperative characteristics of appendiceal tumours in women of childbearing age should be further investigated. Establishing clinical and surgical guidelines is the key to avoid invasive procedures and related adverse outcomes.

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

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.

Imaging of gastrointestinal endometriosis: what the radiologist should know

Deep invasive gastrointestinal endometriosis (DIGIE) is a frequent and severe presentation of endometriosis. Although most cases invade the rectosigmoid colon, DIGIE can involve any portion of the gastrointestinal tract from the stomach to the rectum, and is commonly multifocal and multicentric. Although histopathologic confirmation with surgery remains the gold standard for diagnosis, ultrasound (US) and magnetic resonance imaging (MRI) are the key non-invasive imaging modalities for initial assessment. US may be preferred as a screening study because of its easy availability and low-cost. Pelvic MRI and magnetic resonance enterography (MRE) provide substantial advantages for disease mapping in the pre-operative period, particularly in extensive bowel endometriosis. Although medical management of DIGIE with hormonal therapy can help control symptoms, disease course can be relentless and require surgical intervention. Surgical options depend on, the location; length; depth; circumference; multicentric or multifocal disease. With procedures including simple excision, fulguration of superficial lesions, shaving, disc excision, and segmental resection. A successful treatment outcome is largely dependent on good communication between the treating surgeon and the radiologist, who can provide vital information for effective surgical planning by reporting the key elements that we elaborate upon in this paper.

Expression of nm23-H1, p53, and integrin β1 in endometriosis and their clinical significance

To investigate the expression and clinical significance of nucleoside diphosphate kinase A (nm23-H1), p53, and integrin β1 in endometriosis, normal and ectopic endometrial tissues were collected and the levels of nm23-H1, p53, and integrin β1 proteins were detected by western blotting. We also measured the mRNA expression of nm23-H1, p53, and integrin β1 in endometrial epithelial cells by droplet digital PCR, based on endometrial tissues using laser capture microdissection. Moreover, primary stromal cells from normal and ectopic endometrial tissues were also cultured and treated with different concentrations of estrogen. We assessed the mRNA levels of nm23-H1, p53, and integrin β1 by quantitative PCR. Compared with normal endometrial tissue, the levels of nm23-H1 and p53 proteins were significantly downregulated in ectopic endometrial tissues, while integrin β1 protein was upregulated. The same expression trend in the mRNA levels of nm23-H1, p53, and integrin β1 was also observed in both endometrial epithelial cells and stromal cells. In addition, with increasing estrogen concentration, nm23-H1 and p53 mRNA levels gradually decreased, while integrin β1 mRNA expression increased. Nm23-H1 and p53 may inhibit the progression of endometriosis, while integrin β1 has a promoting effect, and estrogen is involved in this process.

Acute abdominal pain in non-pregnant endometriotic patients: not just dysmenorrhoea. A systematic review

Endometriosis, defined as the presence of functional endometrial tissue outside the uterine cavity, presents mainly with pelvic pain and infertility. Acute abdominal pain in non-pregnant patients with endometriosis might be minimised as a typical feature of the disease, while endometriosis is rarely considered in the differential diagnosis of acute abdominal pain. Our objective was to conduct a systematic review of the current literature of cases of acute abdomen/acute abdominal pain in non-pregnant endometriotic patients. We performed a PubMed/MEDLINE search of studies published from January 1990 to December 2018, selecting English language reports and series of non-pregnant patients with acute abdomen and histological confirmation of endometriosis. The studies were revised by two independent authors. Data were abstracted and compiled for analysis. Fifty articles reporting 62 patients were identified. The complications were classified according to anatomical sites in bowel, urinary tract, and genital organs emergencies. Rarely was the first diagnostic hypothesis endometriosis, misdiagnosis was frequent. The time frame from symptoms onset to management was often long. This is the first systematic review evaluating acute abdomen/acute abdominal pain in non-pregnant endometriotic patients. These conditions are rare but possibly life-threating and require prompt diagnosis and emergent medical or surgical treatment.

Appendicular endometriosis: A case report and review of literature

INTRODUCTION

Patients with appendicular endometriosis (AE) constitute <1% cases of all pelvic endometriosis cases. AE presents with pain in right iliac fossa and symptomatically mimics appendicitis and definitive diagnosis is possible only after histopathological examination of excised appendix.

PRESENTATION OF CASE

In this case report, we present a rare case of appendicular endometriosis in a young woman suffering from pain in right iliac fossa and periumbilical region (on/off) for the past one year. She had a past history of infertility. Blood investigations were normal and CT scan of abdomen demonstrated findings suggestive of appendicitis. Laparoscopic appendicectomy was performed, which revealed 2 cm tumor-like mass (1.5 cm diameter) present at the tip of appendix involving the mesoappendix. There was no ascites, peritoneal or omental deposits or any signs of inflammation. Post-operative recovery was good. Dissected appendix specimen was sent for histopathological examination which confirmed endometriosis of appendix.

DISCUSSION

Gastrointestinal endometriosis (GE) accounts for 3-37% of all endometriosis cases, whereas AE is present in only ∼3% of all GE cases and constitutes <1% of all the endometriosis cases. AE frequently involves tip and body of the appendix. The layers of appendix most commonly affected are muscular and seromuscular (∼2/3rd cases), followed by the serosa (∼1/3rd cases).

CONCLUSION

Thus, appendicular endometriosis is a rare entity and should be included in differential diagnosis in young women presenting with pain in right iliac fossa and having history of infertility.

Atypical Sites of Deeply Infiltrative Endometriosis: Clinical Characteristics and Imaging Findings

Endometriosis is defined as the presence of endometrial tissue that is located outside the uterine cavity and associated with fibrosis and inflammatory reaction. It is a polymorphic and multifocal disease with no known cure or preventive mechanisms. Patients may be asymptomatic or may experience chronic pelvic pain, dysmenorrhea, dyspareunia, or infertility. The pelvic cavity is the most common location for endometriotic implants, which usually affect the retrocervical space, ovaries, vagina, rectosigmoid colon, bladder dome, and round ligaments. Atypical endometriosis is rare and difficult to diagnose. The most common atypical locations are the gastrointestinal tract, urinary tract, lung, umbilicus, inguinal area, breast, and pelvic nerves, as well as abdominal surgical scars. Gastrointestinal lesions are the most common extragenital manifestation, and the diaphragm is the most frequent extrapelvic site. The catamenial nature of the symptoms (occurring between 24 hours before and 72 hours after the onset of menstruation) may help suggest the diagnosis, but imaging by specialists is fundamental to evaluation. Depending on the area affected, radiography, ultrasonography, thin-section computed tomography, or magnetic resonance imaging can be used to assess suspected lesions. Because isolated extragenital endometriosis is rare, concomitant evaluation of the pelvic cavity is mandatory. Surgical excision is the only therapeutic option for definitive treatment, and comprehensive disease mapping is necessary to avoid residual disease. The authors review atypical locations for endometriosis and emphasize the most appropriate imaging protocols for investigation of various clinical manifestations. Online supplemental material is available for this article. ^©RSNA, 2018.

Mimicry of Appendicitis Symptomatology in Congenital Anomalies and Diseases of the Genitourinary System and Pregnancy

INTRODUCTION

Appendicitis is a prevailing cause of acute abdomen, but is often difficult to diagnose due to its wide range of symptoms, anatomical variations, and developmental abnormalities. Urological disorders of the genitourinary tract may be closely related to appendicitis due to the close proximity of the appendix to the genitourinary tract. This review provides a summary of the urological complications and simulations of appendicitis. Both typical and urological symptoms of appendicitis are discussed, as well as recommended diagnostic and treatment methods.

METHODS

Medline searches were conducted via PubMed in order to incorporate data from the recent and early literature.

RESULTS

Urological manifestations of appendicitis affect the adrenal glands, kidney, retroperitoneum, ureter, bladder, prostate, scrotum, and penis. Appendicitis in pregnancy is difficult to diagnose due to variations in appendiceal position and trimester-specific symptoms. Ultrasound, CT, and MRI are used in diagnosis of appendicitis and its complications. Treatment of appendicitis may be done via open appendectomy or laparoscopic appendectomy. In some cases, other surgeries are required to treat urological complications, though surgery may be avoided completely in other cases.

CONCLUSION

Clinical presentation and complications of appendicitis vary among patients, especially when the genitourinary tract is involved. Appendicitis may mimic urological disorders and vice versa. Awareness of differential diagnosis and proper diagnostic techniques is important in preventing delayed diagnosis and possible complications. MRI is recommended for diagnosis of pregnant patients. Ultrasound is preferred in patients exhibiting typical symptoms.

Pediatric incidental appendectomy: a systematic review

Incidental appendectomy is the removal of the vermiform appendix accompanying another operation, without evidence of acute appendicitis. It is generally performed to eliminate the risk of future appendicitis. The risks and benefits of incidental appendectomy during various operations in children have been debated for over a century, but need to be revisited in light of innovations in medical practice, including minimally invasive surgery, improved imaging techniques, and use of the appendix as a tubular conduit for reconstruction. A detailed review was undertaken of the techniques, pathology, risks of appendectomy, utility of the appendix, and incidental appendectomy in the treatment of specific pediatric medical conditions. A comprehensive literature search was performed, and retrieved results were reviewed for relevance to the topic. The decision to perform a pediatric incidental appendectomy relies on informed consideration of the individual patient's co-morbid conditions, the indication for the initial operation, the future utility of the appendix, and the risk of future appendiceal pathology. The discussion includes a variety of situations and comorbid conditions that may influence a surgeon's decision to perform incidental appendectomy.

Endometriosis-induced intussusception of the caecal appendix

Appendicular intussusception is an uncommon entity, with a reported incidence of 0.01%. The diagnosis is difficult and often only performed at the time of surgery. Intussusception has multiple causes including tumours, foreign bodies and polyps. The definitive treatment is surgical, and the extent of resection is determined by the underlying pathology and degree of invagination. Endometriosis is a rare cause of appendicular intussusception, with 194 cases described in the English literature. We report a case of a 42-year-old woman who presented with chronic abdominal pain in the lower right quadrant. A mass at the caecum was identified during investigations for renal stones by CT. Colonoscopy showed a polypoid lesion, with presumed origin in the appendix. Ileocaecal resection was performed because an appendicular tumour was suspected. Pathological examination identified endometriosis of the appendix and associated peritoneum with invagination of the caecum. The patient was discharged 7 days after surgery and is currently asymptomatic.

Routine histopathologic examination of appendectomy specimens: retrospective analysis of 1255 patients

The objective of this study was to analyze the clinical benefit of histopathologic analysis of appendectomy specimens from patients with an initial diagnosis of acute appendicitis. We retrospectively analyzed the demographic and histopathologic data of 1255 patients (712 males, 543 females; age range, 17-85 years) who underwent appendectomy to treat an initial diagnosis of acute appendicitis. Patients who underwent incidental appendectomy during other surgeries were excluded from the study. Histopathologic findings of the appendectomy specimens were used to confirm the initial diagnosis. Ninety-four percent of the appendectomy specimens were positive for appendicitis. Of those, 880 were phlegmonous appendicitis, 148 were gangrenous appendicitis with perforation, and the remaining 88 showed unusual histopathologic findings. In the 88 specimens with unusual pathology, fibrous obliteration was observed in 57 specimens, carcinoid tumor in 11, Encheliophis vermicularis parasite infection in 8, granulatomous inflammation in 6, appendiceal endometriosis in 2, and 1 specimen each showed mucocele, eosinophilic infiltration, Taenia saginata parasite infection, and appendicular diverticulitis. All carcinoid tumors were located in the distal appendix. Six of the 11 carcinoid tumors were defined by histopathology as involving tubular cells, and the other 5 as involving enterochromaffin cells. Six patients had muscularis propria invasion, 2 patients had submucosa invasion, 2 patients had mesoappendix invasion, and 1 patient had serosal invasion. All patients with tumors remained disease free during the follow-up (range, 1-27 months). We conclude that when the ratio of unusual pathologic findings for appendectomy specimens is considered, it is evident that all surgical specimens should be subjected to careful histologic examination.