Clinicopathological Assesment in Patients with Enterobius vermicularis Infection

OBJECTIVE: Enterobius vermicularis is a common gastrointestinal parasite. Acute appendicitis is one of the most common clinical conditions requiring surgical intervention. The coexistence of enterobiasis and acute appendicitis has attracted the attention of researchers for a long time. In this article, it is aimed to present the characteristics of enterobiasis cases detected in appendectomy specimens in a tertiary healthcare institution. In addition, it is aimed to reveal the differences by comparing the cases diagnosed with acute appendicitis without enterobiasis. METHODS: All cases operated for acute appendicitis between January 1, 2008 and December 31, 2021 were retrospectively evaluated through the hospital registry system. The cases with histopathologically determined E. vermicularis were reviewed and a study group was formed. The control group consisted of patients diagnosed with acute appendicitis for reasons other than enterobiasis, matched with the study group in terms of age and gender. Complete blood count, C-reactive protein (CRP) ultrasonography evaluations were compared between the two groups. RESULTS: During the study period, 3.650 appendectomy materials were examined; E. vermicularis was detected in 1.32% (n=48) cases, and acute appendicitis was present in 33.33% (n=16) of the cases. Lymphoid hyperplasia was the most common histopathological change in the study group (n=25; 52.08%). When compared to the control group, leukocyte, neutrophil, CRP, ultrasonographic appendix diameter values were found to be significantly higher in the control group, and the percentage of eosinophils in the study group (p<0.0001; p<0.0001; p<0.0001; p<0.0001; p=0.001; respectively). CONCLUSION: Enterobiasis is a common parasite especially in children. Rarely, it can be seen in patients with acute appendicitis. Histopathological evaluation is necessary to ensure a safe surgical procedure and to complete the treatment with anthelmintic drugs. Enterobiasis should be kept in mind in cases when the acute phase response is lower than expected.

Seeds or Parasites? Clinical and Histopathological Features of Seeds and Parasites in the Appendix.

OBJECTIVE: Parasites and plant seeds may both be found in appendectomy specimens. Each plant seed has a different appearance and can thus exhibit wide variations under the microscope. Fragmented seeds may histologically mimic parasites. The differential diagnosis between seeds and parasites can be challenging in such cases. This study aimed to determine the incidence of parasites, seeds, and foreign bodies in appendectomy materials and highlight the most characteristic histopathological features associated with these structures. MATERIAL AND METHOD: In this study, pathology slides of 9,480 patients, who underwent appendectomy between 2010 and 2021, were reviewed, and cases that contained parasites, seeds, or foreign bodies were identified. We reviewed the literature on seeds and parasites in appendectomy specimens. RESULTS: Parasites were observed in 56 (0.6%) cases. Of these cases, 45 had Enterobius vermicularis (80%), and 11 had Taenia subspecies (20%). Plant seeds were observed in 47 cases (0.5%), and were macroscopically recognizable in 5 of them as olive, lemon, and cherry seeds. Parasites and seeds were usually observed in the lumen of appendix vermiformis, filled with abundant fecal materials. CONCLUSION: Seeds are seen in approximately 0.5% of the appendectomy specimens. Though rarely seen, the fragmented seed appearance may cause diagnostic difficulties. In this context, the key morphological features of parasites and plant seeds outlined in this study may be helpful in their differential diagnosis.

Molecular and phylogenetic analysis of E. vermicularis in appendectomy specimens from Iran.

Human infection with Enterobius vermicularis occurs worldwide, particularly in children. The role of E. vermicularis in appendicitis is neglected. This study was designed to investigate genotypes of E. vermicularis detected from appendectomy specimens in the human population from Iran and clarify the intra-species variation of the parasite. Seventy appendectomies for acute clinical appendicitis isolates from Azerbaijan and North Khorasan of Iran were used in the present study. The genetic information of Tehran and Hamedan regions was also obtained from GenBank for comparison and analysis. The nucleotide sequence of cytochrome c oxidase subunit 1 (cox1) gene was analyzed to perform genetic differentiation, haplotype network analysis, and population structure. Phylogenetic analysis of all the isolates were included in type B haplogroup. The number of haplotypes in all geographical locations of Iran is not much. Network analysis of sequences for regions such as Thailand, Iran, Denmark, and Poland show three classified subtypes B1, B2, and B3 in the B haplogroup. It seems that the haplotypes of E. vermicularis detected from appendectomy are B type, and divided into three subtypes. Further research using another genetic marker is required to elucidate the genetic variation of the parasites in detail.

Parasitic Appendicitis in 14.797 Cases: A Retrospective Cohort Study

Objective: This study aimed to determine the frequency of Enterobius vermicularis in appendectomy specimens and evaluate the histopathological characteristics of adult and pediatric cases with E. vermicularis infection. Methods: Appendectomies examined from 1 January 2010, to 1 December 2020, were analysed retrospectively. Cases were divided into two groups: under 18 years (children) and 18 and over (adults). Demographic and histopathological characteristics of patients were also examined. Results: Out of 14.797 patients that underwent appendectomy, 6.130 were children and 8.667 were adults. E. vermicularis was detected in 268 patients, wherein 64.2% were children and 35.8% were adults. In the detection of E. vermicularis in appendectomy specimens, the frequency was higher in children compared to that in adults (2.85%, 1.1%, respectively) (p<0.001). Histopathologically, acute appendicitis was defined in 31.7% (n=85) of 268 cases, and E. vermicularis was found to cause a higher rate of acute appendicitis in adults (p<0.001). Conclusion: The frequency of E. vermicularis in appendectomy specimens is higher in children. However, E. vermicularis causes acute appendicitis more frequently in adults.

[Appendiceal schistosomiasis complicated by low - grade appendiceal mucinous neoplasm: a report of two cases].

This report presents two cases with appendiceal schistosomiasis complicated by low-grade appendiceal mucinous neoplasm.

Case of anisakiasis presenting as an Amyand hernia.

This is a case of a 31-year-old male patient who presented with signs and symptoms of an incarcerated inguinal hernia. The patient's preoperative imaging showed a tubular structure in the inguinal canal and given the patient's history at presentation, there was a concern for herniation of the appendix, known as an Amyand hernia. On laparoscopy, there was no evidence of appendiceal involvement and a standard open inguinal hernia was completed. On the final pathology of the hernia sac, roundworms were identified with Y-shaped lateral cords suggesting infection by Anisakis spp. On a further interview with the patient, he revealed that he had recently travelled to Alaska and had consumed raw salmon on a fishing trip. This case demonstrates the importance of a thorough social and travel history. One should also have a low threshold to broaden the differential diagnosis when medical work-up deviates from the standard course.

The neglected role of Enterobius vermicularis in appendicitis: A systematic review and meta-analysis.

Although the main cause of appendicitis is unclear, infection with Enterobius vermicularis is suggested as a neglected risk factor. Since, there is no comprehensive analysis to estimate the prevalence of E. vermicularis in appendicitis; therefore, we conducted a global-scale systematic review and meta-analysis study to estimate the prevalence of E. vermicularis infection in appendicitis cases. PubMed, Scopus, Web of Science and Google Scholar databases were systematically searched for relevant studies published until 15 August 2019. Pooled prevalence of E. vermicularis infection was estimated using the random effects model. Data were classified based on the continents and countries. Moreover, subgroup analyses regarding the gender, the human development index (HDI), and income level of countries were also performed. Fifty-nine studies involving 103195 appendix tissue samples belonging to the individuals of appendicitis were included. The pooled prevalence of E. vermicularis infection was (4%, 95%CI, 2-6%), with the highest prevalence (8%, 95% CI: 0-36%) and lowest prevalence (2%, 95% CI: 1-4%) in Africa and Americas continents, respectively. With respect to countries, the lowest and highest prevalence rates were reported from Venezuela (<1%, 95% CI: 0-1%) and Nigeria (33%, 95% CI: 17-52%), respectively. Indeed, a higher prevalence was observed in females, as well as in countries with lower levels of income and HDI. Our findings indicate the relatively high burden of E. vermicularis infection in appendicitis cases. However, our findings suggest the great need for more epidemiological studies to depth understand overlaps between E. vermicularis infection and appendicitis in countries with lower HDI and income levels.

Findings in Appendectomies with Enterobius vermicularis Infection: Pinworm Is Not A Cause of Appendicitis

Objective: To evaluate the histopathological findings in appendectomy materials with E. vermicularis infection. Methods: Appendectomy materials with E. vermicularis infection of 24 cases were evaluated for the presence of acute inflammation, congestion, hemorrhage, perforation, lymphoid hyperplasia (LH), necrosis, granuloma, fecalith, obliteration, hyalinization, eosinophilic infiltration and mucosal architectural distortion. Results: The frequency of E. vermicularis among 3222 appendectomies that were scanned for the study was 0.74% (24/3222). Female: male ratio was 1:1 and the median age was 12±9.34 years. The most common findings were LH (100%), and congestion (91.7%) Acute inflammation was found in one third (n=8), with phlegmonous inflammation and/or periappendicitis in 4 of them. The patients with periappendicitis were significantly younger (mean age 4 vs. 14.2 years, p=0.008). Feces was present in the lumen in 79.1% of the patients (fecalith in 25%, soft feces in 29.1% and feces mixed with blood and/or suppuration in 25%). In 6 cases (25%), only E. vermicularis was observed in the lumen, with acute appendicitis in 2 of them. Appendiceal lumen was completely obstructed in 12.5% (n=3), while it seemed narrow due to extensive LH in 3 (12.5%) cases. Fibrous obliteration was seen in 4 patients and it was correlated with age and eosinophil count in lamina propria p<0.05. Conclusion: While E. vermicularis infection appears to be an incidental finding in appendectomies rather than being a cause of appendicitis, it probably stimulates LH which may mimic acute appendicitis clinically.

Pathological changes in appendectomy specimens including the role of parasites: A retrospective study of 2400 cases of acute appendicitis.

BACKGROUND: Parasitic infestation of the appendix is uncommon. Parasitic infections can cause inflammation in the appendix and can imitate acute appendicitis clinically. Enterobius vermicularis and Taenia species are among the most common parasitic agents causing acute appendicitis. OBJECTIVE: We have studied the ratio of parasites causing acute appendicitis in appendectomy specimens and whether there is any relationship between the type of the parasite, histopathological type of acute appendicitis, age of the patient, and gender of the patient in the appendectomy cases. MATERIALS AND METHODS: We retrospectively analyzed the data of 2400 patients who underwent appendectomy with the prediagnosis of acute appendicitis between 1st January 2004 and 31st March 2018 at Erzincan University. The age of the patient, gender of the patient, histopathologic type of acute appendicitis, and the type of parasite were retrospectively analyzed. Positive appendectomy specimens for histopathological features of acute appendicitis were classified into four groups: catarrhal appendicitis, suppurative appendicitis, gangrenous appendicitis, and perforated appendicitis. RESULTS: In all, 1451 were males and 949 were females. The mean age was 25.51 years. No acute inflammation was found in 36 appendectomy specimens. The distribution of 2364 cases involving acute appendicitis was as follows: catarrhal appendicitis: 438, suppurative appendicitis: 300, gangrenous appendicitis: 1082, and perforated appendicitis: 544. Parasites were identified in 32 cases. The ratio of appendices to parasites was 1.3%. The number of appendectomy cases with Enterobius vermicularis was 22, and the number with Taenia species was 10. CONCLUSION: Although they are a rare cause of acute appendicitis, parasitic infestations must always be considered. Accurate identification of acute appendicitis and appropriate therapy will improve the quality of life as much as the prevention of acute appendicitis sourced from parasites.

Enterobius vermicularis Appendiceal Colic.

Enterobius vermicularis associated appendiceal colic and acute appendicitis are rarely encountered in the United States. The 9-year-old patient described in this case presented with right lower quadrant abdominal pain, nausea, and vomiting consistent with acute appendicitis and was brought to the operating room for an appendectomy. Intraoperatively a pinworm, E. vermicularis, was visualized and the presumptive diagnosis of acute appendicitis was revised to E. vermicularis associated appendiceal colic. Retrospective review of the preoperative imaging demonstrates the first reported ultrasonographic image of pinworm inhabitance within the appendiceal lumen. The patient was treated postoperatively with a course of albendazole and recovered appropriately. This article reviews the geographic epidemiology, pathophysiology, surgical, and medical treatment recommendations in the management of E. vermicularis diseases of the appendix. Through dissemination of this ultrasonographic imaging, the authors hope to inform other providers about E. vermicularis associated appendiceal colic and reduce the incidence of avoidable surgeries.

Enterobius vermicularis: A Cause of Abdominal Pain Mimicking Acute Appendicitis in Children. A Retrospective Cohort Study.

BACKGROUND: Enterobius vermicularis (EV) is the most common helminthic infection in the world. This small parasite is predominant in the pediatric population. The presence of EV in the appendix can cause or mimick appendicitis. The aim of our study was to compare patients with EV infection and those without EV infection, and to identify predictive factors that may help the diagnosis of EV infection in patients presenting with right iliac fossa pain and avoid negative appendectomy. METHODS: A retrospective analysis of all the appendices removed between January 2012 and December 2016 was conducted at the department of pediatric surgery, Hedi Chaker Hospital, Sfax, Tunisia. According to the final histopathological diagnosis, patients with EV infection were compared to those without EV infection. Data including age, sex, white blood cell (WBC) count, neutrophil count, eosinophil count, C-reactive protein, and ultrasound results for both groups were analyzed and compared. The study protocol was approved by the local hospital ethics committee. Statistical analysis was performed using IBM SPSS, version 20. Descriptive analysis in the form of mean and standard deviation was performed on demographic information. Differences between groups were assessed using the student t-test for continuous variables and the χ2 test and Fisher exact test where appropriate for categorical variables. RESULTS: In total, 540 pediatric appendectomies were performed. Overall, 63.5% of patients were male and 36.5% were female. Mean age was 9.28 ± 2.77 years. 22.2% of procedures were completed laparoscopically, 76.5% were open and 1.3% were converted. The negative appendectomy rate was 11.1%. EV was present in 9.8% of cases. Comparison of clinical, biological, and ultrasound findings between two groups of patients with EV (EV+) and those without EV (EV-) shows a statistical significance for pruritus ani (P < 0.001), WBC count (P < 0.001), neutrophil count (P < 0.001), C-reactive protein (CRP) (P = 0.001), positive ultrasound (P < 0.001), perforation rate (P = 0.009), and negative appendectomy rate (P < 0.001). No significant difference between the two groups was seen when comparing gender (P = 0.271), vomiting (P = 0.130), eosinophil count (P = 0.915), and procedure (P = 0.536). CONCLUSION: EV was seen in 9.8% of pediatric appendectomies in our study. Pruritus ani, normal WBC count, normal neutrophil count, and normal CRP level at presentation could predict EV infection in children who present with right iliac fossa pain.

A hydatic cyst of the appendix mimicking a uterine lateral mass: a case report.

BACKGROUND: Hydatic cyst is a zoonotic disease caused by Echinococcus granulosus. It is a public health problem in Tunisia and remains endemic. It occurs in intra-abdominal organs in 10-15% of the cases, particularly in the liver representing the most common affected organ. The aim of the case is to highlight the scarcity of this appendicle origin and to consider it among the differential diagnosis of any intra-abdominal cystic lesion. CASE PRESENTATION: A 45-year-old Tunisian woman, with no past medical history, was admitted for a pelvic cystic mass. The clinical manifestation as well as the imaging findings were toward a lateral uterine mass. Our patient underwent appendectomy and resection of the mass. The patient had no recurrence at 2 years of follow-up. CONCLUSIONS: An extrahepatic hydatid cyst should be recognized among the differential diagnosis of any intra-abdominal cystic lesion. Treatment should be based on surgical excision. Due to the risk of recurrence, a close follow-up is mandatory.

Enterobius vermicularis (pinworm) infestation in a child presenting with symptoms of acute appendicitis: a wriggly tale!

Acute appendicitis is the most common surgical emergency worldwide. However, it can still present a challenging diagnosis especially in the young, elderly and those individuals of reproductive age, thus encompassing a wide spectrum of varied clinical presentations. Parasitic infections of the appendix are a rare cause of acute appendicitis. However, they must be considered in children presenting with abdominal pain. We report a case of Enterobius vermicularis infestation mimicking the features of acute appendicitis in a 10-year-old girl. This case is a cautionary reminder of the importance of considering E. vermicularis infestation in children presenting with abdominal pain, but who do not have a significantly raised white cell count or high Alvarado scores. A history of anal pruritus is the most characteristic symptom, but the parasites can cause severe abdominal pain mimicking appendicitis. Prompt recognition and a high clinical index of suspicion are required to prevent an unnecessary appendicectomy. Caution is advised when performing a laparoscopic appendectomy, as in our case, to prevent contamination of the peritoneum. This infestation is easily treatable with mebendazole.

Does the Intestinal Parasite Enterobius vermicularis Cause Acute Appendicitis?

OBJECTIVE: Although intestinal parasitic infections rarely cause acute appendicitis, they are common public health problems in undeveloped and developing countries. Parasitic infections should be kept in mind in patients clinically suspected of having acute appendicitis, and treatment procedures should be adopted according to the etiology. METHODS: Herein we presented the cases of four patients with clinical findings of acute appendicitis. Patients were clinically suspected of having acute appendicitis, and Enterobius vermicularis was detected in the pathological examinations of specimens. Pinworm infections are common parasitic infections that may mimic appendicitis. RESULTS: The pathology of the four cases was noted when the file of 186 patients aged between 4 and 72 years who underwent surgery for acute appendicitis in my hospital was retrospectively reviewed. When the appendectomy specimen was examined histopathologically it was understood that acute appendicitis was caused by Enterobius vermicularis parasite. CONCLUSION: In Enterobius infections, performing systemic therapy for patients and their family members is sufficient. To prevent unnecessary appendectomy, this type of infection should be made to ask in the history and clinical findings of patients.

[Enterobius vermicularis enteroparasite role in appendicitis cecal: Enterobiasis and appendicitis]. / Rol del enteroparásito enterobius vermicularis en la apendicitis cecal.

Sixty-five cases of enterobiasis of the cecal appendix are reported by Enterobius vermicularis or Oxiurus vermicularis. Enterobiasis is a cosmopolitan parasite5,8,13 and frequent. It is useful to establish whether it can cause appendicitis and the mechanisms involved. According to the classical literature, E. vermicularis is not a causative agent of appendicitis per se, but allows the reproduction of the germs that infiltrate the wall and produce appendicitis5,9,10. The purpose of the study is to report the prevalence of E. Vermicularis in surgical appendicitis and the anatomopathology to deduce a causal relationship. We report a sample of 2000 surgical pieces of extracted appendages (1992-2003) at the Emergency Hospital of the city of Córdoba, Argentina. On a total of 2000 pieces, we observed 65 cases of appendicular enterobiasis; in 60 cases (3.25%) there was no histopathology of acute inflammation (anodyne cecal appendix). In the remaining 5 cases (0.25%) we observed coexistence of parasites in the appendicular lumen, acute transmural inflammatory infiltrates (acute appendicitis) and fecalitos, which would support the obstructive type etiopathogenesis that leads to the surgical picture. The appendicular location of Enterobius vermicularis would favor the formation of fecalitos in light and the proliferation of germs in the wall that would lead to appendicitis. Reports indicate that the parasitic infection constitutes a percentage of the etiologies in appendicitis and fecalitos are the most common trigger, some parasites (Enterobius vermicularis) may be involved in its formation, although this percentage is minimal9,10,15,16,17 .

Se informan sesenta y cinco casos de enterobiasis del apéndice cecal por Enterobius vermicularis u Oxiurus vermicularis. La enterobiasis es una parasitosis cosmopolita y frecuente. Es útil establecer si puede ser causa de apendicitis y los mecanismos involucrados. Según la literatura clásica, E. vermicularis, no es agente causal de apendicitis per se, pero permite la reproducción de los gérmenes que infiltran la pared y producen apendicitis. El propósito del trabajo es informar la prevalencia de E. vermicularis en apendicitis quirúrgicas y la anatomopatología para deducir una relación causal. Informamos una muestra de 2000 piezas quirúrgicas de apéndices extraídos (1992-2003) en el Hospital de Urgencias de la ciudad de Córdoba, Argentina. Sobre un total de 2000 piezas, observamos 65 casos de enterobiasis apendicular; en 60 casos (3,25 %) no hubo histopatología propia de inflamación aguda (apéndice cecal anodino). En los 5 casos restantes, (0,25 %) observamos coexistencia de parásitos en la luz apendicular, napas de infiltrado inflamatorio agudo transmural (apendicitis aguda) y fecalitos, lo que apoyaría la etiopatogenia de tipo obstructivo que lleva al cuadro quirúrgico. La localización apendicular de Enterobius vermicularis favorecería la formación de fecalitos en la luz y la proliferación de gérmenes en la pared que llevaría a la apendicitis. Reportes señalan que la infección parasitaria constituye un porcentaje de las etiologías en apendicitis y los fecalitos son el desencadenante más común, pudiendo estar implicados en su formación algunos parásitos (Enterobius vermicularis), aunque este porcentaje es mínimo.