BACKGROUND: Actinomycosis is a suppurative and granulomatous inflammation commonly caused by Actinomyces israelii. Due to its rarity and the paucity of characteristic clinical features, diagnosis of intra-abdominal actinomycosis is challenging, especially when the patient has a treatment history of abdominal cancer.
METHODS: The patient is a 72-year-old man who has a history of multiple abdominal surgeries for rectal cancer, including low anterior resection for primary rectal cancer, partial hepatic resection for metachronous liver metastasis, and Hartmann surgery for local recurrence. The patient has also undergone parastomal hernia repair using the Sugarbaker method. One year after hernia repair, computed tomography (CT) identified a mass lesion between the abdominal wall and the mesh, suggesting the possibility of peritoneal recurrence of rectal cancer. The accumulation of fluorodeoxyglucose (FDG) was evident via positron emission tomography-CT (PET-CT), while tumor marker levels were within the normal range. On laparotomy, the small intestine, abdominal wall, mesh, colon, and stoma were observed to be associated with the mass lesion, and en bloc resection was carried out. However, postoperative histopathological examination revealed an actinomyces infection without any cancerous cells.
CONCLUSIONS: This case highlights the challenges faced by surgeons regarding preoperative diagnosis of actinomycosis, especially when it occurs after the resection of abdominal cancer. Also, this case reminds us of the importance of a histopathological examination for abdominal masses or nodules before starting chemotherapy.

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.

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.

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.

BACKGROUND: 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.
METHODS: 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 2.5cm.
CONCLUSIONS: 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.
CONCLUSIONS: 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.

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.
METHODS: 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.

Actinomyces are part of normal oral flora and cause disease only when the normal mucosal barrier is breached. Reported annual incidence of actinomycosis is 1 case per 300,000 persons (Weese and Smith, Arch Intern Med 135:1562-1568, 1975). Preoperative diagnosis of abdominal actinomycosis is difficult. An accurate diagnosis is always obtained by histological examination and often requires surgical resection. This case of mesenteric panniculitis due to fish bone penetrating the gut wall and lodging in the omentum has been taken for its rare presentation.