Actinomycosis: a great pretender. Case reports of unusual presentations and a review of the literature

Abdominal actinomycosis presented as acute abdomen with intra-abdominal multiple tumors: A case report

INTRODUCTION AND IMPORTANCE

Actinomycosis, a rare infection caused by Actinomyces spp., typically presents as a chronic condition affecting various regions, particularly the cervicofacial, thoracic, and abdominal areas. Its diagnosis is often difficult due to symptom overlap with malignancies and other infections. This report details a case of abdominal actinomycosis mimicking multiple intra-abdominal tumors, complicating diagnosis and treatment.

CASE PRESENTATION

A 67-year-old male with uncontrolled type 2 diabetes presented with generalized abdominal pain, nausea, vomiting, constipation, and significant weight loss. Physical examination revealed distention and severe abdominal tenderness. Laboratory tests showed leukocytosis and anemia. Diagnostic laparotomy revealed multiple intra-abdominal tumors. Histopathology confirmed actinomycosis without malignancy or tuberculosis. Intravenous amoxicillin was started; however, the patient discharged himself against medical advice after two days due to personal reasons unrelated to his treatment plan. He returned three months later with persistent abdominal pain and additional hepatic lesions. Extended antibiotic therapy for 12 months led to the resolution of symptoms during follow-up.

CLINICAL DISCUSSION

Abdominal actinomycosis is rare and often associated with conditions like diabetes. This case underscores the infection's potential to mimic malignancy and highlights the need for considering actinomycosis in differential diagnoses of acute abdomen, especially in immunocompromised patients. The patient's uncontrolled diabetes likely contributed to the infection's development and spread.

CONCLUSION

Abdominal actinomycosis can present acutely, mimicking neoplastic diseases with multiple intra-abdominal masses. Early recognition and prolonged antibiotic therapy are essential to prevent systemic spread, especially in immunocompromised individuals. Clinicians should consider actinomycosis in patients with poorly controlled diabetes and abdominal symptoms.

Dot-in-circle sign in cervical actinomycotic mycetoma: An extremely rare case report

Actinomycosis is an unusual, chronic granulomatous infection caused by Actinomycetes spp. The organism also causes mycetoma, a neglected tropical disease in endemic regions. We present a very uncommon case of extensive actinomycosis of the soft tissues in the neck with perivertebral extension that showed the dot-in-circle sign on magnetic resonance imaging. A 29-year-old male patient presented with progressively enlarging hard posterior neck swelling of 4 years duration. Subsequently, magnetic resonance imaging showed the dot-in-circle sign in an avidly enhancing infiltrative lesion with extensive involvement of the neck and perivertebral soft tissue. The pathologic examination was in line with actinomycosis. The patient responded to high doses of combination parenteral and oral antibiotics.

Delayed Presentation of Actinomycosis Following Orthognathic Surgery: An Old Nemesis and a Difficult Diagnosis: Case Presentation and Review of the Literature

Study Design

Review of the literature with report of Case.

Objective

To review the presentation of Actinomycosis specifically as it occurs with mandibular osteotomies.

Methods

A review of the literature and report of an additional case.

Results

While minor infections secondary to local factors are usually seen 2-3 weeks after surgery, late infections are rare. Host factors may play a role. When actinomycosis is diagnosed, long-term antibiotics are necessary.

Conclusions

Actinomycosis is very rare following orthognathic surgery. It usually occurs in the mandible and following a sagittal split. Time of presentation for actinomycosis can vary from 6 weeks to 4 months as in our case. Infections occurring this late after surgery should be treated with suspicion of actinomycosis obtaining both cultures and tissue biopsies. Treatment involves an incision and drainage and long-term antibiotics.

Pericardial actinomycosis

A man in his 50s, with a history of night sweats and weight loss, presented acutely with dyspnoea and chest pain. Imaging revealed right middle lobe consolidation and a large pericardial effusion. The diagnosis of actinomycosis was made using endobronchial ultrasound-guided sampling from the pericardial effusion. An orthopantomogram demonstrated that the source was a large cavity in the left lower wisdom tooth. This tooth was extracted before the completion of his antibiotic course, and the patient made a full recovery. Cardiac actinomycosis is rare, and there are few case reports describing endobronchial ultrasound-guided sampling of pericardial fluid.

Cervical Facial Actinomycosis Complicated by Bacteremia After 30 Years of Dental Neglect: Successful Treatment With Ceftriaxone and Metronidazole

Actinomycosis is an uncommon bacterial infection, caused by the Actinomyces species, and it most commonly presents as cervicofacial actinomycosis. The most common risk factors for actinomycosis are poor dental hygiene, oral surgery, maxillofacial trauma, local tissue inflammation, and diabetes. We discuss a case of a male patient in his 50s with 30 years of poor dental hygiene, complicated by tobacco use, who presented with septic shock and was found to have cervicofacial actinomycosis and bacteremia. The treatment of severe actinomycosis often involves prolonged penicillin-based antibiotic therapy. This is the first case in the literature to describe the successful treatment of cervicofacial actinomycosis and bacteremia with intravenous cefepime (later narrowed to ceftriaxone) and oral metronidazole.

Actinomyces spp. Prosthetic Vascular Graft Infection (PVGI): A Multicenter Case-Series and Narrative Review of the Literature

BACKGROUND

Actinomycosis represents a challenging and under-reported complication of vascular surgery. Optimal management of Actinomyces spp. prosthetic vascular graft infection (PVGI) is highly uncertain because of the paucity of reports on this disease.

METHODS

We conducted a retrospective case-series of Actinomyces-PVGI that occurred in the last five years in two major university hospitals in northern Italy. We searched for previously published cases in the scientific literature.

RESULTS

We report five original cases of Actinomyces spp. prosthetic vascular graft infection following aortic aneurysm repair. Our literature review retrieved eight similar cases. Most patients were immunocompetent males. Most infections were polymicrobial (11/13 cases), with a prevalence of A. odontolyticus involvement (3/13 cases were associated with. Salmonella spp. infection). All cases had a late presentation (≥4 months from graft placement), with 61% associated with an aorto-enteric fistula. All patients received antibiotic therapy, but the duration was highly heterogeneous (from two weeks to life-long antibiotics). The patients without surgical revision experienced septic recurrences (2/13), permanent dysfunction (1/13), or a fatal outcome (2/13), while of the remainder who underwent vascular graft explant, six recovered completely and one developed a periprosthetic abscess. In two cases follow-up was not available.

CONCLUSIONS

This case-series aims to raise the diagnostic suspicion and to describe the current management of Actinomyces-PVGIs. We highlight a high heterogeneity in antibiotic duration, choice of the antibiotic regimen, and surgical management. Higher reporting rate is advisable to produce better evidence and optimize management of this rare complication of vascular surgery.

Xanthogranulomatous cholecystitis in a patient with ulcerative colitis and primary sclerosing cholangitis: A case report

Chronic gallbladder disease due to xanthogranulomatous cholecystitis is uncommon, and its symptoms are generally vague. While there is no firm evidence to link xanthogranulomatous cholecystitis to primary sclerosing cholangitis or ulcerative colitis. The patient is a 41-year-old male with a history of ulcerative colitis, primary sclerosing cholangitis, and biliary stenting who complained of symptoms of anorexia, jaundice, and pruritus. In the initial ultrasound exam, there was evidence of intrahepatic and extra-hepatic bile duct dilation along with a significant and mass-like circumferential thickening of the gallbladder wall. Magnetic resonance cholangiopancreatography was performed for further evaluation, which indicated increased gallbladder wall thickness, containing multiple T2 hyper-signal nodules while the mucosal layer was intact. There was also a filling defect in the common bile duct's distal portion. These findings matched a xanthogranulomatous cholecystitis diagnosis and a possibly malignant lesion in the distal of the common bile duct. The patient ultimately had a cholecystectomy, and pathology findings confirmed the diagnosis of xanthogranulomatous cholecystitis. Biopsy specimens obtained from the distal of the common bile duct lesion were microscopically identified as intramucosal adenocarcinoma. In patients with a history of primary sclerosing cholangitis who present with nonspecific symptoms suggesting chronic gallbladder disease and radiologic evidence of circumferential gallbladder wall thickening containing intramural nodules and intact mucosa, xanthogranulomatous cholecystitis should be kept in mind.

The epidemiology, clinical presentation and treatment outcomes in CNS actinomycosis: a systematic review of reported cases

BACKGROUND

CNS actinomycosis is a rare chronic suppurative infection with non-specific clinical features. Diagnosis is difficult due to its similarity to malignancy, nocardiosis and other granulomatous diseases. This systematic review aimed to evaluate the epidemiology, clinical characteristics, diagnostic modalities and treatment outcomes in CNS actinomycosis.

METHODS

The major electronic databases (PubMed, Google Scholar, and Scopus) were searched for the literature review by using distinct keywords: "CNS" or "intracranial" or "brain abscess" or "meningitis" OR "spinal" OR "epidural abscess" and "actinomycosis." All cases with CNS actinomycosis reported between January 1988 to March 2022 were included.

RESULTS

A total of 118 cases of CNS disease were included in the final analysis. The mean age of patients was 44 years, and a significant proportion was male (57%). Actinomycosis israelii was the most prevalent species (41.5%), followed by Actinomyces meyeri (22.6%). Disseminated disease was found in 19.5% of cases. Most commonly involved extra-CNS organs are lung (10.2%) and abdomen (5.1%). Brain abscess (55%) followed by leptomeningeal enhancement (22%) were the most common neuroimaging findings. Culture positivity was found in nearly half of the cases (53.4%). The overall case-fatality rate was 11%. Neurological sequelae were present in 22% of the patients. On multivariate analysis, patients who underwent surgery with antimicrobials had better survival (adjusted OR 0.14, 95% CI 0.04-0.28, p value 0.039) compared to those treated with antimicrobials alone.

CONCLUSION

CNS actinomycosis carries significant morbidity and mortality despite its indolent nature. Early aggressive surgery, along with prolonged antimicrobial treatment is vital to improve outcomes.

Case report of actinomycotic liver abscess following COVID-19 infection

Introduction and importance

In the last few years, the novel coronavirus, named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), generated a large health care problem worldwide. Due to the immunomodulation effect of the virus the number of opportunistic infections has also increased.

Case presentation

We present the unique case of a patient who was diagnosed with an actinomycotic liver abscess after coronavirus disease 2019 (COVID-19) without the presence of any chronic disease or mucosal injury.

Clinical discussion

According to the results of the computer tomography (CT scan) and the liver biopsy, the patient was treated with antibiotics and ultrasound-guided drainage.

Conclusion

With this case we would like to draw attention to the possible occurrence of liver abscesses caused by an opportunistic pathogen following COVID-19.

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SARS-CoV-2 is an acute respiratory infection, that could result immune dysregulation.

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Immunocompromised patients have a higher risk for opportunistic infections (e.g. actinomycosis).

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Actinomycosis could result in liver abscess, which is a rare type of the liver abscesses.

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Actinomycosis followed by COVID-19 infection disease could be a post-COVID syndrome.

Pancreatic actinomycosis treated by antibiotics after diagnosis using endoscopic ultrasound-guided fine-needle biopsy

A 71-year-old man who had undergone total gastrectomy, partial pancreatectomy, and splenectomy with Roux-en-Y reconstruction for gastric cancer was referred for a possible pancreatic tail tumor. Contrast-enhanced computed tomography showed mold-like, poor contrast lesion in the dilated main pancreatic duct in the pancreatic tail. Endoscopic ultrasonography revealed a slightly hyperechoic solid lesion that occupied the lumen of the main pancreatic duct. Linear calcification was observed in the lesions on both computed tomography and endoscopic ultrasonography, and endoscopic ultrasound-guided fine-needle biopsy was performed. Histopathology revealed sulfur grains and inflammatory infiltrates with no malignant findings. We also performed an anaerobic culture using fine-needle biopsy specimens, and Actinomyces meyeri was detected in the culture results. After confirming susceptibility, oral administration of amoxicillin was initiated. After 8 months of treatment, the size of the lesion slightly decreased, and the antibiotics treatment is still ongoing. This shows that such cases could be diagnosed based on histological findings and anaerobic culture using a fine-needle biopsy specimen, and unnecessary surgery may be avoided. In the case of tumors developed in the residual pancreas without typical malignant imaging findings, pancreatic actinomycosis should be considered as a differential diagnosis.

Actinomyces capricornis sp. nov., isolated from the oral cavity of a Japanese serow

A novel Gram-positive, facultatively anaerobic, rod-shaped, nonspore forming, nonmotile organism was isolated from a Japanese serow oral cavity. Designated strain MAS-1^T , it is most closely related to Actinomyces bowdenii DSM 15435^T , with which it shares 98.07% sequence homology in the 16S ribosomal RNA gene. The primarily detected cellular fatty acids in strain MAS-1^T were C_16:0 and C_18:1 w9c. The predominant respiratory quinone was MK-9 (H₄ ). The major polar lipids were phosphatidylcholines, phosphatidylinositols, and glycophospholipids. The genomic DNA GC content of the isolate was 71.3 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between MAS-1^T and its related species were 23.5%-39.5% and 82.11%-91.01%, respectively, which were below the threshold (70% and 95%, respectively) for species delineation, indicating that strain MAS-1^T represents a novel species. Strain MAS-1^T can be differentiated from A. bowdenii by their reactions to naphthol-AS-BI-phosphohydrolase, α-galactosidase, β-galactosidase, and N-acetyl-β-glucosaminidase, as well as differing acid production from glycogen. Based on the results of genotypic, phenotypic, and biochemical analyses, herein it is proposed that the identified bacteria can be classified as a novel species, Actinomyces capricornis sp. nov., strain MAS-1^T (=JCM 34236^T  = DSM 111732^T ).

Clinical features of actinomycosis: A 20-year experience of a single institute in Southern China

BACKGROUND

Actinomycosis is a rare indolent infectious disease with nonspecific clinical presentations that delay diagnosis. Although actinomycosis is thought to be more prevalent in developing countries, data from developing countries are scarce. This study aimed to profile actinomycosis in developing countries and identify how it differed from profiles of developed countries.

METHODS

Patients fulfilling the inclusion criteria for actinomycosis from Nanfang Hospital in southern China between January 1999 and December 2018 were retrospectively analyzed. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance.

RESULTS

Thirty‑one patients were included in this study. The disease was diagnosed predominately in the orocervicofacial (n = 14), cardiothoracic (n = 11), abdominopelvic (n = 5), and soft tissue (n = 1) regions. Diagnosis was obtained by either histopathology (n = 29, 94%) or microbiology (n = 2, 6%). Only one-third of patients presented with general symptoms, such as fever and weight loss. Ten were lost during follow-up, and the median duration of antibiotic use was 93.5 days (interquartile range 28-300), whereas the median follow-up time was 34 months (interquartile range 9-132). Ten patients receiving complete resection of the lesion were cured without postoperative use of antibiotics. Only one patient relapsed during the follow-up period.

CONCLUSIONS

Actinomycosis is a rare disease even in developing countries, and both misdiagnosis and missed diagnosis are common. Diagnosis was often delayed and was obtained postoperatively from histopathology in developing countries. Hence, clinicians should be aware of this disease in patients with high risk factors. In the future, specific molecular methods may help to improve early diagnosis and treatment.

Cervicofacial Actinomycosis in the Pediatric Population: Presentation and Management

BACKGROUND

Infection caused by Actinomyces species is a rare cause of head and neck infection in children. This chronic cervicofacial infection can present with localized swelling, abscess formation, sinus drainage and can be complicated by osteomyelitis.

METHODS

Presented are 2 pediatric cases of secondary actinomycosis in the context of congenital lesions: 1 patient with a previously excised preauricular sinus and another with a persistent sublingual mass. A comprehensive literature search was conducted for reported cases of pediatric actinomycosis in the cervicofacial region.

RESULTS

Both cases presented were successfully treated with a combination of complete surgical excision of the lesions and prolonged antibiotic therapy. Thirty-four pediatric cases of cervicofacial actinomycosis are reviewed, 2 presented herein, and 32 from the published literature. There was equal gender distribution and the median age was 7.5 years. The most common site for infection was the submandibular area. Four (12%) of cases arose in pre-existing congenital lesions. Most patients were treated with penicillin-based antibiotics for a median duration of 6 months following surgical excision or debridement.

CONCLUSIONS

Actinomycosis is a rare infection of the cervicofacial region; secondary infections arising from congenital lesions of the head and neck are even more rare. A previously excised pre-auricular sinus and a sublingual dermoid cyst are not previously reported sites of infection. Actinomycosis should be suspected in chronically draining sinuses of the head and neck region and confirmed through anaerobic culture. Osteomyelitis is a potential complication and magnetic resonance (MR) imaging is warranted. Long-term antibiotic therapy with a penicillin-based antibiotic and surgical excision should be considered.

Primary Lacrimal Canaliculitis with clinically detected concretions: One-snip punctoplasty with lateral canaliculotomy vs. punctum sparing canalicular curettage

PURPOSE

To compare two distinct surgical techniques in the management of chronic Primary Lacrimal Canaliculitis (PLC) with clinically detectable concretions.

MATERIALS AND METHODS

Inclusion criteria: Patients presenting with symptoms consistent with the diagnosis of primary lacrimal canaliculitis (PLC) with ocular involvement were gathered. Gomori-Grocott Methenamine Silver test was used for concretion staining. Two groups were identified based on the surgical technique. Group A consisted of patients who underwent a punctum sparing canalicular curettage using a chalazion curette, while the patients in Group B underwent one-snip punctoplasty with lateral canaliculotomy. Failure was defined as recurrence of the initial symptoms at any time (ocular and canalicular inflammation with purulent discharge and pouting punctum). The results were analyzed by comparisons using a Fisher's exact test.

RESULTS

Ninety-six consecutive patients (96) with a confirmed diagnosis of PLC underwent surgical treatment between 1987 and 2017. Data were collected and divided based on the surgical technique discussed above (Group A and B). Group A: 51 cases with a mean follow-up time of 22 months [1-224] presented with a mean age of 51.5 [25-83] and a surgical failure rate of 19.6%. Group B: 45 patients with a mean follow-up time of 27 months [1-176], a mean age of 68 [17-87] years and a surgical failure rate of 4.4%. Statistical significance was demonstrated, with a p-value of 0.033, odds ratio (OR) of 0.1936 and Standard Deviation (SD) at a 95% confidence interval of [0.0195-0.9885].

CONCLUSIONS

One-snip punctoplasty with lateral canaliculotomy is a simple, fast and effective procedure that allows better anatomical visualization intraoperatively and is thus shown to be statistically superior to punctum sparing canalicular curettage using a chalazion curette.

A very rare case of possible actinomycosis of the mandible from the Middle Ages

OBJECTIVE

Documented cases of actinomycosis in archaeological skeletons are very rare, especially from Central Europe. Our contribution will help facilitate the differential diagnosis of this disease for other paleopathologists.

MATERIAL

This paper describes a pathological finding of the skeleton of a 40-year-old male from a burial ground in Sady-Špitálky (Czech Republic) dated to the 10th-12th century.

METHODS

The affected skeleton was evaluated as a probable case of actinomycosis on the basis of a detailed macroscopic, X-ray and histological examination. The osteolytic foci examined were compared with similar changes caused by tuberculosis, syphilis and mycoses.

RESULTS

The character and location of the defect on the mandible is indicative of organ actinomycosis and is also reflected by the lytic lesion observed on a lumbar vertebra.

CONCLUSIONS

The described case can be considered one of the very rare paleopathological findings of possible actinomycosis in humans in Central Europe.

SIGNIFICANCE

Good evidence of bone actinomycosis findings may be beneficial for further paleopathological and epidemiological studies, especially for research focused on the diachronic development of actinomycosis in Europe. In doing so, all available factors, such as hygiene habits, nutrition, social structure and overall health of the population that could be causally related to its origin, course and treatment, can be taken into account.

LIMITATIONS

The mandible of the studied individual was damaged, especially in the area affected by the lesion, so the paleopathological analysis was difficult to perform.

SUGGESTION FOR THE FUTURE RESEARCH

In future, actinomycosis in this skeleton may be confirmed by bio-molecular analysis.

Thoracoabdominal actinomycosis - Chameleon through kaleidoscope

Actinomyces is a gram-positive anaerobic bacterium that generally inhabits the human commensal flora of the bronchial system, the gastrointestinal and urogenital tract. In the rare case of becoming invasive under certain circumstances, the resulting Actinomycosis affects most commonly cervicofacial, thoracic, abdominal and pelvic regions. Due to its rarity and presenting with nonspecific clinical symptoms, thoracic and/or abdominal Actinomycosis in particular are highly intriguing clinical conditions that can easily be mistaken for other diseases including malignancies. Astute considerations are therefore necessary whenever we are challenged diagnostically to allow early diagnosis and thus avoiding gratuitous invasive surgery. In order to highlight different issues of this ultimate chronic disease we report a particular case of thoracoabdominal Actinomycosis.

Microbial Association with Genus Actinomyces in Primary and Secondary Endodontic Lesions, Review

The main reason for root canal treatment failure is the persistence of microorganisms after therapy, or the recontamination of the root canal system due to an inadequate seal. In the mouth, Actinomyces spp. constitute a significant part of the normal flora, which is indicative of their ability to adhere to oral tissue and resist cleansing mechanisms, such as salivary flow. This review, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), aims to clarify the prevalence of microbial genera that are associated with the genus Actinomyces in primary and secondary endodontic infections (primary outcome), and to identify the most prevalent species of the Actinomyces genus in endodontic lesions (secondary outcome). A total of 11 studies were included in the qualitative and quantitative analysis, and a total of 331 samples were analyzed. Bacteria of the genus Actinomyces were found in 58 samples, and 46 bacterial genera were detected in association with bacteria of the genus Actinomyces. Bacteria of the genus Streptococcus and Propionibacterium were those most frequently associated with Actinomyces in the endodontic lesions considered, and Actinomyces israelii was the most frequently involved species.

Actinomycotic Osteomyelitis of the Hand and Wrist Treated with Pharmacotherapy Alone: A Case Report

CASE

Primary infection by Actinomyces is uncommon because susceptibility to infection requires breakdown of the normal protective mucosal barrier. Furthermore, involvement of the upper extremity is rare. This case report presents clinical, radiological, and pathological findings in a 26-year-old patient with actinomycosis of the hand that was treated successfully by pharmacotherapy alone without any surgical debridement.

CONCLUSION

Primary actinomycoses of the hand and upper extremity present as a challenging condition. It requires a high index of clinical suspicion and histopathologic diagnosis to guide treatment, typically involving antimicrobial therapy. This case highlights the usefulness of conservative treatment with antimicrobial therapy without surgical debridement.

Mimicking uterine malignancy: Pelvic actinomycosis with giant uterine leiomyoma

Pelvic actinomycosis is a rare disease which is hard to be distinguished from other diseases such as malignant tumors and tuberculosis due to its nonspecific clinical signs and symptoms. If pelvic actinomycosis can be diagnosed preoperatively, the patients can be cured with antimicrobial therapy avoiding surgery. It is especially of concern to distinguish pelvic actinomycosis from pelvic mass, if there is a history of intrauterine device use. We report a case of pelvic actinomycosis that was diagnosed after the postoperative pathology of a suspected uterine malignancy.

A Case Report of Pelvic Actinomycosis and a Literature Review

BACKGROUND The aim of this study was to report the clinical diagnosis and treatment of a case of pelvic actinomycosis in our hospital and provide a review of recent literature. CASE REPORT The patient was a 54-year-old woman who was admitted to our hospital due to "bilateral lower abdominal tenderness accompanied with anorexia and vomiting for 3 months". After admission, a variety of imaging examinations found pelvic space-occupying lesions, which were considered as malignant. She underwent surgery and pelvic actinomycosis was diagnosed by postoperative pathology. Postoperatively, she was treated with a high-dose sufficient course of penicillin (20 million U, iv gtt) for 14 days and she is currently under close follow-up for 1 year, with no recurrent symptoms. CONCLUSIONS Pelvic actinomycosis is rare and often forms mass invasion into the tissue structure around the pelvic cavity, which is easily misdiagnosed as ovarian malignant tumor. The criterion standard for diagnosing an infection is culture, with histopathology aiding the diagnosis.

Ocular Actinomycosis Mimicking Meningioma

Orbital actinomycosis is an unusual clinical manifestation of orbital infection caused by Actinomyces species. Herein we report a case of orbital actinomycosis in a 67-year-old woman with recurrent swelling and erythema around her left eye with an orbital mass initially thought to be a meningioma.

Intra-abdominal Actinomycosis Imitating Sigmoid Colon Cancer: A Case Report

Actinomycosis is a rare bacterial disease characterized by chronic or subacute suppurative inflammation. Abdominal actinomycosis is rarer and accounts for approximately 20% of all actinomycosis cases. In the literature, patients who underwent surgery for actinomycosis mimicking malignant tumors have been reported. Most of these patients had mucosal trauma and inflammation signs. It is often difficult to diagnose abdominal actinomycosis preoperatively and often impossible to distinguish it from a malignant tumor. We present a case that preoperatively was diagnosed as a malignant tumor but pathological evaluation reported to be diverticulitis and actinomycosis. This case can increase the awareness about this disease, which is possible to be treated non-surgically.

Unusual aetiology of lymphocyte-predominant exudative pleural effusion: primary mediastinal actinomycosis

Actinomycosis is a rare infectious bacterial disease typically involving cervicofacial, abdominopelvic, or thoracic regions, caused by Actinomyces species. However, involvement of the mediastinum as the primary site of origin is extremely rare. An elderly patient complained of left-sided chest pain. The chest radiograph revealed pleural effusion, which revealed lymphocyte-predominant exudates. Chest computed tomography showed a soft tissue mass in the left anterior mediastinum. Positron emission tomography revealed an increased uptake of 18F-fluorodeoxyglucose in this lesion. To exclude malignancy and make a confirmative diagnosis, a mediastinal biopsy was performed through video-assisted thoracic surgery. Finally, mediastinal actinomycosis was diagnosed. We report herein a case of mediastinal actinomycosis mimicking lung malignancy presented with recurrent lymphocyte-predominant pleural fluid exudate. In patients with a recurrent or unexplained exudative pleural effusion, it may be worthwhile to consider a hidden foci of actinomycosis.

Actinomyces lilanjuaniae sp. nov., isolated from the faeces of Tibetan antelope (Pantholops hodgsonii) on the Qinghai-Tibet Plateau

Two novel, Gram-stain-positive, non-motile, facultatively anaerobic, rod-shaped bacteria (strains 2129^T and 2119) were isolated from the faeces of Tibetan antelopes (Pantholops hodgsonii) on the Qinghai-Tibet Plateau, PR China. The 16S rRNA gene sequences of the strains showed highest similarity values to Actinomyces timonensis DSM 23838^T (92.9 and 92.8 %, respectively), and phylogenetic analysis based on 16S rRNA gene and genomic sequences indicated that strains 2129^T and 2119 represent a new lineage. Strains 2129^T and 2119 could ferment d-adonitol and d-xylose, but were unable to utilize d-mannose and d-melibiose nor produce esterase (C4) and proline arylamidase. The G+C contents of the two strains were both 69.0 mol%. Their genomes exhibited less than 40.4 % relatedness in DNA-DNA hybridization tests (below 70 % as the recommended threshold for new species) with all available genomes of the genus Actinomyces in the NCBI database. The major fatty acids of the two strains were C_18 : 1ω9c and C_16 : 0, and the major polar lipids were diphosphatidylglycerol, glycolipid, phosphatidylinositol, phosphatidyl inositol mannoside and phosphoglycolipid. Based on the results of genotypic, phenotypic and biochemical analyses, it is proposed that the two unidentified bacteria be classified as representing a novel species, Actinomyces lilanjuaniae sp. nov. The type strain is 2129^T (=CGMCC 4.7483^T=DSM 106426^T).

Mixed Actinomyces israelii and Aggregatibacter actinomycetemcomitans infection causing empyema necessitatis and multiple skin abscesses in an immunocompetent patient

A 45-year-old- man presented with left chest wall pain, swelling and cough. Over a 2-month period he developed abscesses in the right foot, right anterior thigh, left buttock and left chest. Incision and drainage of the soft tissue abscesses and video-assisted thoracoscopic surgery to drain the loculated empyema contiguous with the chest wall abscess were performed as surgical management. Gram stain showed beaded Gram-positive rods and the culture initially grew Aggregatibacter actinomycetemcomitans and Eikenella corrodens Pathological evaluation of the pleura showed sulfur granules and organisms consistent with Actinomyces spp. on Gomori methenamine silver stain; Actinomyces israelii was recovered in culture with extended incubation. The patient was treated for 3 weeks with ceftriaxone and oral metronidazole, followed by oral amoxicillin. Culture of A. actinomycetemcomitans with other findings consistent with actinomycosis warrants 6-12 months of antibiotic therapy.

A case series of actinomycosis from a single tertiary care center in Saudi Arabia

Actinomycosis is an uncommon but curable chronic infection caused by Actinomyces spp. The cervicofacial region is the most susceptible to infection; however, other sites may also become infected. Data on the current prevalence of this rare disease in Riyadh, Saudi Arabia is lacking. We herein report a case series of four patients with actinomycosis from a single tertiary care center in Riyadh, Saudi Arabia. Three patients presented to us with slowly progressing actinomycosis and one patient developed an acute abdomen, secondary to viscus perforation. Two of the patients had cervicofacial disease, including hard palate actinomycosis. Tissue cultures were sent for three patients; however, tests for actinomycosis were negative. Subsequently, the diagnosis was made through histopathological examination. Therapy involved a combination of surgical resection and debridement and prolonged antimicrobial treatment tailored to each patient. The cases reported in this series highlight the difficulty in diagnosing actinomycosis. For most patients, the diagnosis was delayed or accidentally discovered on histopathological examination. We conclude that increased awareness among physicians is needed for early diagnosis and treatment of actinomycosis.

Actinomycosis of the omentum with invasion of the abdominal wall, small bowel and transverse colon mimicking malignancy

We report the case of a 59-year-old Russian man who presented with a painless, slow-growing, epigastric mass. CT revealed a large heterogeneous mass within the omentum infiltrating into adjacent tissues. During diagnostic laparoscopy, the omental mass was noted to be firm, raising the suspicion of malignancy. Surgical en-bloc resection of the mass, including the posterior rectus sheath, transverse colon and small bowel, was performed with primary anastomoses at laparotomy. Histological examination was inconsistent with malignancy and revealed the mass to be actinomycosis, confirmed by microscopy and gram staining. Surgical resection was followed by an 8-week course of penicillin and doxycycline antibiotic therapy. This treatment resulted in full clinical and radiological recovery with no complications. Although the clinical and radiological findings, in this case, were highly suspicious of malignancy, abdominal actinomycosis should be considered a differential diagnosis in patients with infiltrative abdominal masses and mild constitutional symptoms.

Identification and diversity of Actinomyces species in a clinical microbiology laboratory in the MALDI-TOF MS era

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a reliable tool for bacterial identification. This study compared the Bruker MALDI-TOF BioTyper MS (MBT) and 16S rRNA gene sequencing for the identification of Actinomyces and Actinotignum spp. The MBT identified 68/77 (88.3%) of Actinomyces isolates to the genus-level and 44/77 (57.1%) of Actinomyces isolates to the species-level using the manufacturer's identification criteria. The MBT did not yield reliable identification for only 1/77 (1.3%) and generated no identification for 8/77 (10.4%) of the isolates. No misidentifications were found. Discordance at the species level was observed for eight isolates. Overall, the MBT demonstrated good concordance with the 16S rRNA gene sequencing with the exception of the closely related species A. naeslundii, A. viscosus and A. oris. A variety of Actinomyces spp. were isolated from orocervicofacial/dental specimens, but only a limited number of species were isolated from urine or intra-abdominal specimens. This study confirms the utility of MBT in the identification of Actinomyces spp. and describes the diversity and anatomic niche of species in human clinical specimens from various body sites.

Noncontiguous finished genome sequences and descriptions of Actinomyces ihuae, Actinomyces bouchesdurhonensis, Actinomyces urinae, Actinomyces marseillensis, Actinomyces mediterranea and Actinomyces oralis sp. nov. identified by culturomics

The taxonogenomic approach, including the culturomics techniques, is now currently used to isolate and characterize new bacteria. These approaches notably allowed us to discover six new species of the Actinomyces genus: Actinomyces ihuae strain SD1, Actinomyces bouchesdurhonensis strain Marseille-P2825, Actinomyces urinae strain Marseille-P2225, Actinomyces marseillensis strain Marseille-P2818, Actinomyces mediterranea strain Marseille-P3257 and Actinomyces oralis strain Marseille-P3109. Each is the type strain of the corresponding bacterial species. 16S ribosomal RNA gene sequence comparison was used to classify these strains among the Actinomyces genus. These strains are all Gram positive, rod shaped and facultative aerobic. We describe the main characteristics of each bacterium and present their complete genome sequence and annotation.

Masking and misleading: concomitant actinomycosis and B-cell lymphoma - a case report and review of literature

We report a 72-year-old patient who presented with an ulcerated palatal mass, weight loss and adrenal insufficiency. Repeated biopsies from the mass revealed actinomycosis with no features of malignancy, while computed tomography scanning revealed a left maxillary sinus mass with invasive features and bilateral large adrenal masses. Blood and urine investigations showed adrenal insufficiency. The patient was treated as actinomycosis with adrenal involvement and was given intravenous penicillin and intravenous hydrocortisone. However, his condition did not improve and new signs appeared, that of left facial swelling and lymphadenopathy. A repeat biopsy of the palatal and adrenal masses revealed B-cell lymphoma. This case highlights the possibility that actinomycosis and lymphoma may share similar clinical presentations and may coexist. Either may mask and/or mimic the other, thus causing a delay in diagnosis. We describe the clinical progress and review the related literature. Interestingly, 9 out of the 12 reported cases of concomitant actinomycosis and malignancy (including this case) involve haematological malignancy. A high index of suspicion and treatment response reassessment is important in the management of either rare clinical entity.

Diagnosis and Management of a Cryptoglandular Actinomycotic Fistula-in-Ano: An Update on 7 New Cases and a Review of the Literature

Purpose

Primary anal actinomycosis of cryptoglandular origin, a rare cause of anal suppurative disease, requires specific management to be cured. The aims of this retrospective study were to describe clinical, morphological, and microbiological features of this entity and to evaluate management practices for new cases observed since 2001.

Methods

This was a retrospective case series conducted at the Diaconesses-Croix Saint-Simon Hospital in Paris.

Results

From January 2001 to July 2016, 7 patients, 6 males and 1 female (median, 49 years), presenting with an actinomycotic abscess with a cryptoglandular anal fistula were included for study. The main symptom was an acute painful ischioanal abscess. One patient exhibited macroscopic small yellow granules (“sulfur granules”), another “watery pus” and a third subcutaneous gluteal septic metastasis. All patients were overweight (body mass index ≥ 25 kg/m²). Histological study of surgically excised tissue established the diagnosis. All the patients were managed with a combination of classical surgical treatment and prolonged antibiotic therapy. No recurrence was observed during follow-up, the median follow-up being 3 years.

Conclusion

Actinomycosis should be suspected particularly when sulfur granules are present in the pus, patients have undergone multiple surgeries or suppuration has an unusual aspect. Careful histological examination and appropriate cultures of pus are needed to achieve complete eradication of this rare, but easily curable, disease.

Actinomycosis, a lurking threat: a report of 11 cases and literature review

Actinomycosis remains characteristically uncommon, but is still an important cause of morbidity. Its clinical presentation is usually indolent and chronic as slow growing masses that can evolve into fistulae, and for that reason are frequently underdiagnosed. Actinomyces spp is often disregarded clinically and is classified as a colonizing microorganism. In this review of literature, we concomitantly present 11 cases of actinomycosis with different localizations, diagnosed at a tertiary hospital between 2009 and 2016. We outline the findings of at least one factor of immunosuppression in > 90% of the reported cases.

Refractory actinomycosis of the humerus

Actinomycosis is a chronic, opportunistic infection caused by Actinomyces species, such as Actinomyces bacillus. Actinomycosis in long bones is very rare. To the best of our knowledge, isolated primary actinomycosis of the humerus is rarely reported in literature. We present a rare case of a refractory primary actinomycosis of the humerus. A 66-year-old man with no history of concomitant conditions was admitted to our hospital with a history of a tumour on the distal third of the left arm as a result of a closed trauma without fracture 20 years before. Pathological anatomy samples showed the presence of Actinomyces. Cultures were subjected to a prolonged incubation of 21 days under aerobic and anaerobic conditions and were always negative. He underwent several surgical procedures and received long-term antibiotic therapy with poor outcome. Primary actinomycosis in long bones is uncommon. Diagnosis may be challenging: considering the small number of case studies reported in the literature, symptoms are not specific, and the organism is difficult to isolate. Antibiotic treatment may not be sufficient to improve the clinical condition, and surgical alternatives should be considered.

Actinomycosis is not Frequent in the Periapex But is a Persistent Lesion

Periapical actinomycosis caused by a gram-positive anaerobic pathogen characterizes a typical extra-radicular infection. This study determined the frequency and correlated the content of bacteria colonies with the of periapical actinomycosis size. The study comprised a total of 218 periapical lesions (PL) (cysts, granulomas or abscess). The specimens embedded in paraffin were sliced into 4-µm sections and stained with hematoxylin-eosin, Gram, Periodic Acid-Schiff (PAS) and Grocott's stain. The presence of bacterial colonies composed of filamentous structures labeled with the histochemical stains were described as Actinomyces, and for each case, the bacterial colonies were counted and measured. The correlation between the number and size of bacterial colonies and the size of PL was tested using Pearson's adjusted correlation coefficient. From 218 PL, bacterial colonies were identified in 64 biopsies. Seven cases (0.3%) fulfill the criteria for diagnosis of periapical actinomycosis. All of cases were therapy-resistant and did not showed periapical repair after 12 months of follow-up. Periapical surgery or dental extraction was performed. The correlation test indicated no correlation between the number of bacterial colonies and the lesion size (p=0.752, r=-0.148). However, a larger bacterial colony size generally resulted in a larger periapical lesion (P=0.000, r=0.657). The frequency of periapical actinomycosis was low, and this lesion should be included in the differential diagnosis of PL. The size of the Actinomyces colonies seemed to contribute to increase the size of the periapical lesion.

Actinomyces radicidentis and Actinomyces haliotis, coccoid Actinomyces species isolated from the human oral cavity

There are few reports on the bacterial species Actinomyces radicidentis in the literature. In this study, putative A. radicidentis isolates were collected from 16 root canal samples from 601 examined patients. The isolates were examined by biochemical tests, 16S rRNA gene sequencing, Arbitrarily-primed (AP-) PCR, antibiotic susceptibility testing, and MALDI-TOF analyses. In parallel, two A. radicidentis reference strains and two putative A. radicidentis isolates from United Kingdom were tested. Sixteen of the 18 isolates were confirmed as A. radicidentis. The remaining two isolates, both of which were isolated from root canals (one from Sweden and the other from the UK), but were identified as Actinomyces haliotis by sequencing ∼ 1300 base pairs of the 16S rRNA-gene. This isolates had a divergent, but between them similar, AP-PCR pattern, and a common distribution of sequence signatures in the 16S rRNA gene, but were not identified by MALDI-TOF. A. haliotis is a close relative to A. radicidentis, hitherto only been described from a sea-snail. The identity of A. haliotis was confirmed by a phylogenetic tree based on 16S rRNA gene sequences with species specific sequences included, and by additional biochemical tests. The examined bacteria exhibited similar antibiotic susceptibility patterns when tested for 10 separate antibiotic classes with E-tests (bioMérieux). The MIC₉₀ for β-lactams (benzylpenicillin and cefuroxime) and vancomycin was 0.5 mg/L, for colistin and ciprofloxacin 8 mg/mL and for the other antibiotic classes ≤ 25 mg/mL The isolation of A. haliotis from infected dental root canals cast doubt on the accepted opinion that all Actinomyces infections have an endogenous source.

A Complicated Thread: Abdominal Actinomycosis in a Young Woman with Crohn Disease

Crohn disease is a chronic inflammatory condition that primarily affects the gastrointestinal tract. Typical manifestations include fever, weight loss, fatigue, and abdominal pain, and abdominal abscesses and fistulae are frequent complications. Abdominal actinomycosis is a subacute or indolent disease associated with Actinomyces spp. Symptoms can be very similar to those of Crohn disease, and fistulae are also common. Since ulcerations in the intestinal tract are thought to be caused by Actinomyces escaping from the gut lumen and establishing intra-abdominal infection, it seems likely that abdominal actinomycosis may occur in patients with inflammatory bowel disease. We report a case of abdominal actinomycosis in a woman with active Crohn disease.

[Disseminated actinomycosis treated with clindamycin]

Actinomycosis is a rare bacterial disease caused by Actinomyces spp., an anaerobic bacteria from the oropharynx, digestive, and female genital tracts. Initial clinical presentation often mimics malignancy, which can lead to a delay in diagnosis. Cervico-facial, genitourinary, digestive, and respiratory features are the most frequent. Few cases are reported in children and risk factors are not well known in this population. We report on the case of an 8-year-old boy with disseminated actinomycosis with cervico-facial, pulmonary, and bone involvement caused by Actinomyces israelii. The infiltrative appearance initially suggested malignancy and the patient was started on chemotherapy for presumed histiocytosis. Evaluation of subsequent tissue samples demonstrated the presence of filamentous structures consistent with fungal or filamentous bacterial infection. Prolonged culture yielded the correct diagnosis. The patient had a severe allergic reaction to piperacillin/tazobactam and was therefore transitioned to clindamycin to complete a 9-month course. This treatment, which has not been reported in children, led to a favorable clinical, biological, and radiological response, with a good clinical tolerance.

Abdominal actinomycosis in the last 10 years and risk factors for appendiceal actinomycosis: review of the literature

BACKGROUND/AIM

Actinomycosis is a granulomatous disease caused by filamentous, gram-positive, anaerobic bacteria. Actinomycetes are commensal inhabitants of the oral cavity and intestinal tract but acquire pathogenicity through invasion of breached or necrotic tissue.1397645907In abdominal actinomycosis (AA), the appendix and ileocecal region are usually involved. The aim of this study was to characterize patients diagnosed with AA and to establish the risk factors for appendiceal actinomycosis, including a short review of the literature.

MATERIALS AND METHODS

We conducted a prospective cohort study of all patients diagnosed with AA in the University Hospital Marques de Valdecilla (Santander-Cantabria) from January 2003 to October 2013. We also conducted a short review of the literature.

RESULTS

We characterized the epidemiological features of patients diagnosed with AA and risk factors for the involvement of the appendix, as most of the cases were misdiagnosed as appendicitis. Risk factors for appendiceal actinomycosis are no antecedents of carcinoma (P = 0.034) and previous incorrect diagnosis (P = 0.006).

CONCLUSION

AA is a rare and chronic infection. It is only reported in case reports in the literature. We present the largest series of patients diagnosed with AA. Half of the patients had morbidities, mostly carcinoma, and penicillin was the preferred treatment. More studies are needed to characterize patients affected with AA and to establish the correct treatment.

Massive paediatric cervicofacial actinomycoses masquerading as an ulcerative malignancy

Background

Paediatric cervicofacial actinomycosis is a rare infectious disease caused by Actinomyces spp. and usually presents as a chronic, suppurative and granulomatous inflammation with a propensity to mimic malignant conditions.

Case presentation

We discuss the case of an 11-year-old African female who presented with a chronic disfiguring cervical mass evolving over a 9 months period for which she had several unyielding consultations. Appropriate clinical and para-clinical evaluations were paramount to the diagnosis of an Actinomyces infection. We review the literature on its epidemiology, clinical presentation, diagnosis, treatment and prognosis.

Conclusion

Actinomycosis still poses a diagnostic challenge. It is important for clinicians to consider the possibility of such rare infections in apparently malignant looking masses and also in lesions not responding to several antimicrobial treatments. The condition generally carries a good prognosis if recognised early and histopathological diagnosis is the gold standard.