Actinomycosis: a differential diagnosis for appendicitis. A case report and review of the literature

Actinomyces as a rare cause of appendicitis: a case report

Actinomycosis remains a rare and often underdiagnosed cause of appendicitis with only 10% of cases diagnosed prior to surgery. It is an important cause to consider particularly in the setting of an indolent infection with nonspecific symptoms. We present a 22 years old male who presented with 3 weeks history of lower abdominal pain who underwent laboratory investigations and imaging studies suggestive of acute appendicitis. He underwent an emergency laparoscopic caecectomy with histopathology of the specimen suggestive of actinomycosis. He recovered well postoperatively and was discharged home with a prolonged course of oral penicillins. Preoperative diagnosis of actinomycosis is uncommon and accounts for ~10% of cases. Definitive diagnosis is usually through histopathology or tissue/fluid culture. Treatment usually involves a combination of surgical resection and antibiotic therapy with a success rate of >90%.

Appendiceal actinomycosis mimicking malignant tumor: a rare case report

Introduction

Actinomycosis is an uncommon bacterial infection caused by Actinomyces bacteria that typically progresses slowly and leads to the formation of masses. Although it commonly affects the cervicofacial area, about 20% of cases occur in the abdominopelvic region. Because the disease can be mistaken for a tumour due to its infiltrative mass-like nature on imaging, over 90% of cases are only diagnosed following surgery and histological confirmation. This report describes a case of an appendicular mass, initially suspected to be a malignant tumour, but eventually diagnosed as appendiceal actinomycosis.

Presentation of case

Upon initial presentation, a 53-year-old woman with type II diabetes mellitus and no prior surgical history, displayed abnormal appendiceal uptake during a PET-computed tomography (CT) scan conducted for a suspected spinal tumour. Colonoscopy did not indicate any notable observations, and the patient chose to defer immediate action. Several months later, a CT scan revealed an increased mass-like appearance of the appendix compared to the previous PET-CT scan. After multidisciplinary discussions, a right laparoscopic hemicolectomy was recommended due to suspected malignancy. However, histological staining on microscopy confirmed actinomycosis originating from the appendix.

Discussion

Chronic appendicitis with radiologic features similar to appendiceal carcinoma, or abdominal masses located in the ileocecal area, in patients with or without a previous surgical history should raise suspicion of actinomycosis.

Conclusion

Appendiceal actinomycosis should be considered in the differential diagnosis in the aetiology of chronic appendicitis mimicking appendiceal carcinoma. Awareness and accurate diagnosis of appendiceal actinomycosis can prevent unnecessary extended surgery as was performed in this case.

Causal effects of gut microbiota on appendicitis: a two-sample Mendelian randomization study

Background

Previous research has posited a potential correlation between the gut microbiota and the onset of appendicitis; however, the precise causal connection between appendicitis and the gut microbiota remains an unresolved and contentious issue.

Methods

In this investigation, we performed a Mendelian randomization (MR) analysis employing publicly accessible summary data extracted from genome-wide association studies (GWAS) to elucidate the potential causal nexus between the gut microbiota and the development of appendicitis. We initially identified instrumental variables (IVs) through a comprehensive array of screening methodologies, subsequently executing MR analyses using the Inverse Variance Weighted (IVW) technique as our primary approach, supplemented by several alternative methods such as MR Egger, weighted median, simple mode, and weighted mode. Additionally, we implemented a series of sensitivity analysis procedures, encompassing Cochran's Q test, MR-Egger intercept test, Mendelian Randomized Polymorphism Residual and Outlier (MR-PRESSO) test, and a leave-one-out test, to affirm the robustness and validity of our findings.

Results

Our investigation indicates that an elevated prevalence of Deltaproteobacteria, Christensenellaceae, Desulfovibrionaceae, Eubacterium ruminantium group, Lachnospiraceae NK4A136 group, Methanobrevibacter, Desulfovibrionales, and Euryarchaeota is inversely associated with the risk of appendicitis. Conversely, we observed a positive correlation between an increased abundance of Family XIII, Howardella, and Veillonella and the susceptibility to appendicitis. Sensitivity analyses have corroborated the robustness of these findings, and Mendelian randomization analyses provided no indications of reverse causality.

Conclusion

Our Mendelian randomization (MR) analysis has unveiled potential advantageous or detrimental causal associations between the gut microbiota and the occurrence of appendicitis. This study offers novel theoretical and empirical insights into the understanding of appendicitis pathogenesis, along with its implications for preventive and therapeutic strategies.

Detection of methanogens in peri-appendicular abscesses: Report of four cases

The aetiology of appendicular abscess is predominantly microbial with aerobic and anaerobic bacteria from gut flora. In this study, by using specific laboratory tools, we co-detected Methanobrevibacter oralis and Methanobrevibacter smithii among a mixture of enterobacteria including Escherichia coli, Enterococcus faecium and Enterococcus avium in four unrelated cases of postoperative appendiceal abscesses. These unprecedented observations raise a question on the role of methanogens in peri-appendicular abscesses, supporting antibiotics as an alternative therapeutic option for appendicitis, including antibiotics active against methanogens such as metronidazole or fusidic acid.

Actinomyces in Crohn's-like appendicitis

AIMS

Appendicitis with a Crohn's-like histological appearance generally raises concern for Crohn's disease, Yersinia infection, and interval appendectomy. Actinomyces infection is a recognised cause of chronic appendicitis that can histologically mimic Crohn's disease.

METHODS AND RESULTS

We report on 20 cases of appendicitis with Crohn's-like histological features that were due to Actinomyces. Most patients presented with acute or chronic abdominal pain. Imaging studies suggested a mass in five cases. Two patients had interval appendectomy. Histological features showed Crohn's-like appendicitis in 16 cases, with moderate to marked fibrosis and granulomas in seven cases. The other four cases had less consistent histological findings. None of the patients developed Crohn's disease during the follow-up interval (median, 37 months).

CONCLUSIONS

Actinomyces can be associated with Crohn's-like appendicitis with marked fibrosis, transmural inflammation, lymphoid hyperplasia, and granulomas.

A rare case of subacute appendicitis, actinomycosis as the final pathology reports: A case report and literature review

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Actinomycosis represents only the 0.02% of causes of acute apendicitis.

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We present the first case of appendiceal actinomycosis reported in México.

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As to our knowledge, this is the first case in the literature with appendiceal actinomycosis without been perforated.

Introduction

Acute appendicitis is the most common indication for an emergency abdominal surgery in the world, with a lifetime incidence of around 10%. Actinomycetes are the etiology of appendicitis in only 0.02%–0.06%, having as the final pathology report a chronic inflammatory response; less than 10% of the cases are diagnosed before surgery. Here, we present the case of a subacute appendicitis secondary to actinomycosis.

Case report

A 39-year-old male presented with a twelve-day evolution of intermittent abdominal pain in the right lower quadrant, treated at the beginning with ciprofloxacin and urinary analgesic. The day of the admission he referred intense abdominal pain with nausea. An open appendectomy was preformed, finding a tumor-like edematous appendix with a diameter of approximately 2.5 cm.

Discussion

Actinomyces are part of the typical flora of the oral cavity, gastrointestinal tract and vagina. The predominant form of human disease is A. Israelii, it requires an injury to the normal mucosa to penetrate and cause disease. Abdominal actinomycosis involves the appendix and caecum in 66% of the presentations, of these, perforated appendicitis is the stimulus in 75% of the cases. A combination of antibiotic therapy and operative treatment resolves actinomycosis in 90% of cases.

Conclusion

Abdominal actinomycosis is an uncommon disease been the common presentation a perforated appendicitis, here we present a less common presentation of it with a non-perforated appendix.

[Acute abdomen with actinomycosis of the colon: A case report]

BACKGROUND

Actinomyces infection is a chronic inflammatory process that can sometimes, clinically and radiographically, closely mimic a malignant tumour, which may lead to giving a delayed or inappropriate treatment.

CLINICAL CASE

Male 41 years old, with no previous history, with abdominal pain of one month onset, as well as weight loss, intermittent fever and diarrhoea. He developed acute abdomen and underwent surgery, finding a tumour in the distal ileum with necrosis and punctiform perforations. A resection was performed on the affected part of the ileum and colon, as well as an ileostomy using Hartmann's procedure.

CONCLUSIONS

Actinomycosis is a disease that must be considered by the surgeon when faced with a clinical picture of subacute onset with intermittent fever, weight loss, abdominal pain, and even anaemia in patients with abdominal and retroperitoneal abscesses or previous history of surgery.

Appendiceal Crohn’s disease clinically presenting as acute appendicitis

AIM: To determine the incidence of appendiceal Crohn’s disease (CD) and to summarize the characteristic histologic features of appendiceal CD.

METHODS: We reviewed the pathology files of 2179 appendectomy specimens from January 2007 to May 2013. The computer-assisted retrieval search facility was utilized to collect specimens. We selected those cases that were diagnosed as CD or chronic granulomatous inflammation and defined the final diagnosis according to the histologic findings of CD, including transmural lymphocytic inflammation, non-caseating epithelioid granulomas, thickening of the appendiceal wall secondary to hypertrophy of muscularis mucosa, mucosal ulceration with crypt abscesses, mucosal fissures, and fistula formation.

RESULTS: We found 12 cases (7 male and 5 female patients, with an average age of 29.8 years) of appendiceal CD. The incidence of appendiceal CD was 0.55%. The chief complaints were right lower quadrant pain, abdominal pain, lower abdominal pain, and diarrhea. The duration of symptom varied from 2 d to 5 mo. The histologic review revealed appendiceal wall thickening in 11 cases (92%), transmural inflammation in all cases (100%), lymphoid aggregates in all cases (100%), epithelioid granulomas in all cases (100%), mucosal ulceration in 11 cases (92%), crypt abscesses in 5 cases (42%), perforation in 2 cases (17%), muscular hypertrophy in 1 case (8%), neural hyperplasia in 5 cases (42%), and perpendicular serosal fibrosis in 8 cases (67%).

CONCLUSION: A typical and protracted clinical course, unusual gross features of the appendix and the characteristic histologic features are a clue in the diagnosis of appendiceal CD.

Actinomyces bacteremia in association with tubo-ovarian abscesses and hysteroscopic sterilization

BACKGROUND

Actinomyces infection is well-documented in intrauterine devices but has not been previously associated with hysteroscopic sterilization using coil inserts. Additionally, abscesses associated with these implants have been observed in few cases.

CASE

A 31-year-old multiparous woman with a history of hysteroscopic sterilization with coil inserts 18 months previously presented with several weeks of pelvic pain. Despite percutaneous drainage of intra-abdominal abscesses, her pain and fevers persisted. Blood cultures were positive for Actinomyces infection, and exploratory laparotomy demonstrated abscesses at both coil sites.

CONCLUSION

When a causative organism cannot be identified or the when patient does not respond to standard antibiotic therapy, Actinomyces infection should be considered because prolonged antibiotic therapy is necessary.

Renal hemorrhagic actinomycotic abscess in pregnancy

Actinomyces israelii is a gram-positive, filamentous anaerobic bacteria colonizing the oral and gastrointestinal tracts. Retroperitoneal actinomycotic abscess is uncommon and its rare presentation as a hemorrhagic mass may be confused with malignancy. We present a case of this unusual infection complicating pregnancy. Increased awareness of actinomycotic abscess in the differential diagnosis of renal mass concerning for malignancy is critical to early recognition and treatment of this rare infection and most importantly, avoidance of unnecessary surgical intervention.

Unusual presentations of actinomycosis; anterior abdominal wall and appendix: report of three cases

BACKGROUND

Primary actinomycosis of the anterior abdominal wall and appendix are very rare clinical entities. An accurate diagnosis is generally obtained by histological examination, and treatment often requires surgical resection.

CASE REPORT

In this study we presented two cases of primary actinomycosis involving the anterior abdominal wall and a third one located in the appendix.

CONCLUSION

Actinomyces Israelii can involve all anatomic structures of the abdomen. Although preoperative diagnosis is difficult, the combination of surgery and antibiotic treatment results in complete treatment in the majority of cases.

A case of frozen pelvis: primary actinomycosis of urinary bladder in a young boy

We report a case of urinary bladder actinomycosis in childhood. In children abdominal actinomycosis is rare and unlikely involves the urinary tract, so it is often misdiagnosed. An 7-year-old boy was referred to a secondary level hospital because of abdominal pain and dysuria. Physical examination revealed a left hypochondrial mass. Hypothesizing a pelvic rhabdomyosarcoma, a biopsy with mini-laparotomy access was performed. The first histopathological analysis did not show any malignant cells, and a 14-day antibiotic course was ineffective. Reoperation and biopsy was needed, and the histopathological examination made the diagnosis possible.

Abdominal actinomycosis masquerading as an omental tumor in a 12-year-old female

We herein report a case of abdominal actinomycosis in a 12-year-old girl in whom an omental primary tumor was suspected before surgery. The patient began to experience intermittent lower left abdominal pain. Abdominal computed tomography (CT) scans were inconclusive at this time, but 6 months later, CT and magnetic resonance imaging (MRI) examinations showed a 7-cm, tumor-like lesion in the left abdominal cavity; malignancy could not be ruled out. The tumor, which originated in the omentum and adhered strongly to the left abdominal wall, was resected along with approximately 90 % of the omentum, the peritoneum in contact with the mass, and the posterior layer of the rectus abdominal sheath, under suspicion of a malignant tumor. However, omental actinomycosis was the final pathological diagnosis. The patient's antibiotic treatment was changed to a penicillin-series oral antibiotic to prevent recurrence of the actinomycosis. The patient was discharged from our hospital 16 days after the first surgery, but she developed three episodes of ileus; the first two required surgery. The patient has had no further recurrences of actinomycosis or postoperative ileus 20 months after discharge.

Unusual histopathological findings in appendectomy specimens: A retrospective analysis and literature review

AIM: To document unusual findings in appendectomy specimens.

METHODS: The clinicopathological data of 5262 patients who underwent appendectomies for presumed acute appendicitis from January 2006 to October 2010 were reviewed retrospectively. Appendectomies performed as incidental procedures during some other operation were excluded. We focused on 54 patients who had unusual findings in their appendectomy specimens. We conducted a literature review via the PubMed and Google Scholar databases of English language studies published between 2000 and 2010 on unusual findings in appendectomy specimens.

RESULTS: Unusual findings were determined in 54 (1%) cases by histopathology. Thirty were male and 24 were female with ages ranging from 15 to 84 years (median, 32.2 ± 15.1 years). Final pathology revealed 37 cases of enterobiasis, five cases of carcinoids, four mucinous cystadenomas, two eosinophilic infiltrations, two mucoceles, two tuberculosis, one goblet-cell carcinoid, and one neurogenic hyperplasia. While 52 patients underwent a standard appendectomy, two patients who were diagnosed with tuberculous appendicitis underwent a right hemicolectomy. All tumors were located at the distal part of the appendix with a mean diameter of 6.8 mm (range, 4-10 mm). All patients with tumors were alive and disease-free during a mean follow-up of 17.8 mo. A review of 1366 cases reported in the English literature is also discussed.

CONCLUSION: Although unusual pathological findings are seldom seen during an appendectomy, all appendectomy specimens should be sent for routine histopathological examination.

Case report: actinomycosis of the appendix--an unusual cause of acute appendicitis in children

Abdominal actinomycosis in children is a rare disease, which is occasionally found on histologic examination after an operation for acute appendicitis. Because of its nonspecific clinical and radiological signs and symptoms and low prevalence, the diagnosis is hardly ever made before the patient undergoes an operation and tissue is available for pathologic evaluation. When the diagnosis is made, the patient should be treated with the appropriate long-term antibiotics. With antibiotic therapy, the prognosis is favorable. We describe a 13-year-old girl who presented with acute appendicitis and was found to have abdominal actinomycosis after undergoing open appendectomy, which was treated successfully with penicillin and piperacillin-tazobactam.

Actinomycosis of the appendix mimicking appendiceal tumor: A case report

Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.