UNASSIGNED: 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.
METHODS: 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.
UNASSIGNED: 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.
CONCLUSIONS: 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.

Actinomycosis is a rare chronic granulomatous disease that manifests with nonspecific symptoms of abdominal pain, anorexia, and weight loss. The disparity in the presentation of this condition presents a tremendous diagnostic challenge. There are few reports of Actinomyces species causing spontaneous bacterial peritonitis without previous localized masses or abscesses have been published. We provide a case of spontaneous bacterial peritonitis secondary to Actinomyces species in a 46-year-old woman with uterine fibroids and a lack of preceding abscess. Although rare, spontaneous bacterial peritonitis because of Actinomyces should be considered in differential in female patients without pre-existing liver disease presenting with spontaneous bacterial peritonitis.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

This report describes the case of a 54-year-old female who presented with the constitutional symptoms of lethargy, weight loss, and asthenia. She had been extensively investigated for possible gynaecological malignancy but with no definitive outcome achieved. The symptoms were persistent and, partly due to occurring during the coronavirus disease 2019 (COVID-19) pandemic, a decision was made to progress with surgical management. Following an oncology multidisciplinary meeting, a decision was made for a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Intra-operatively, there was an incidental finding of an extensive tumour infiltrating the liver, colon, anterior abdominal wall and urinary bladder. A surgical resection with ileostomy was performed on suspicion of an underlying malignancy. Unexpectedly, the histopathological diagnosis revealed actinomycosis. Following this discovery, our entire management plan was altered, and the patient was treated with a prolonged course of antibiotics and recovered well.

Actinomycosis is a rare, chronic, and suppurative disease caused by Actinomyces species, which are filamentous, obligate, Gram-positive bacteria. This report presents a case of anterior abdominal actinomycosis in a 40-year-old female with a history of intrauterine contraceptive device placement. The patient presented with severe abdominal pain, an abdominal mass, low-grade fever, and weight loss. Imaging studies revealed thickening of the left rectus abdominis muscle and pericolic fat stranding. An exploratory laparotomy confirmed dense adhesions from the transverse colon and omentum to the abdominal wall with a purulent discharge. Resection of the affected colon segment and primary anastomosis were performed. Histopathological examination revealed characteristic colonies of Actinomyces within abscesses, confirming the diagnosis of actinomycosis. The patient received appropriate antibiotic therapy and showed improvement. This case highlights the rare occurrence of abdominal wall actinomycosis associated with an intrauterine contraceptive device and emphasizes the importance of considering actinomycosis in the differential diagnosis of abdominal pathologies. Thus, medical history related to intrauterine contraceptive device use should be regarded as in differentials if a patient presents vague abdominal mass and pain, and small details in history should be emphasized and looked upon so that a timely decision can be made for the betterment of the patient.

Intraabdominal infection by Actinomyces species, although a rare condition, usually occurs after a disruption of the mucosal barrier in a peritoneal organ. This infection is characterized by the development of an extended and persistent inflammatory and fibrotic reaction that can be mistaken for other pathogens or different etiologies, like tumors or inflammatory diseases. It can present as an abscess, a stricturing tissue with multiple adhesions, and/or a fistulization. Early diagnosis, targeted and prolonged antimicrobial therapy, and optimal drainage when indicated, are the key to success. The authors present a case where laparotomic hysterectomy was complicated by a superficial and an organ/space surgical site infection due to Actinomyces with a posterior developing of a colo-vaginal fistula that was treated surgically.

A 14-year-old boy presented to the hospital with pain in the right lower abdomen. His condition was diagnosed as acute appendicitis. An emergency operation was performed, and histopathological examination revealed an actinomycete-related organism in the excised appendicitis specimen. On 16S rRNA gene sequence analysis, \"Candidatus Actinobaculum timonae\" was identified, which is the first known case in a pediatric patient.

Abdominal actinomycosis is a rare infection and the non-recognition of this particular microorganism may led to a prolonged septic process and recurrent disease. We hereby present a case report of 53 years-old woman with a secondary peritonitis due to this microorganism and our option to perform a long course of penicillin derived antibiotics, after suture of a perforated gastric ulcer caused by a foreign body.

Actinomycosis is an uncommon, endogenous, and chronic infection with varied and nonspecific clinical features such as abdominal, pelvic or cervical masses, ulcerative lesions, abscesses, draining fistula, fibrosis, and constitutional symptoms. The disease ensues when the bacteria disrupt the mucosal barrier, invade, and spread throughout interfascial planes. Currently, the diagnosis of actinomycosis is challenging because of its very low frequency and depending on the clinical presentation it may masquerade malignancies. Therapy consists initially in intravenous penicillin, followed by an oral regimen that may be extended until a year of treatment. A timely diagnosis is crucial to avoid extensive therapeutic attempt as surgery. However, a biopsy or drainage of abscesses and fistula\'s tract may be required not only as a diagnostic procedure as part of the therapy. We report the case of a 72-year-old woman with an abdominal mass initially misdiagnosed as a liposarcoma. A second biopsy of a skin lesion of the abdominal wall made the diagnosis of actinomycosis, avoiding a major surgical procedure. The patient was treated with a long-term course of antibiotics with favorable outcome. Liposarcoma was ruled out after the patient\'s full recovery with antibiotics and the misdiagnosis was credit to the overconfidence on the immunohistochemical positivity to MDM2.

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.