[A case of abdominal actinomycosis]

Area of Science:

• Medical Microbiology
• Surgical Pathology

Background:

• Abdominal actinomycosis is a rare, chronic granulomatous infection caused by Actinomyces species.
• It often presents insidiously, mimicking other intra-abdominal pathologies like malignancy or inflammatory bowel disease.

Observation:

• A 43-year-old male presented with abdominal pain and a palpable mass, later diagnosed as an actinomycotic abscess.
• Laparotomy revealed a sarcoma-like mass invading the ileum, bladder, and other intra-abdominal organs.
• Analysis of 71 Japanese patients over 32 years showed actinomycosis frequently affected the transverse colon, not just the ileocecal region.

Findings:

• Actinomycotic abscesses can present as large, invasive masses, complicating surgical management.
• Unlike previous literature, this review found the transverse colon to be as common a site as the ileocecal region.
• Acute appendicitis preceded infection in only a minority of cases, suggesting other etiologies.

Implications:

• Abdominal actinomycosis should be considered in the differential diagnosis of unexplained abdominal masses, especially in middle-aged adults.
• Prompt diagnosis and appropriate antibiotic therapy (e.g., penicillin) are essential for successful management and good prognosis.
• Further research into the pathogenesis and diagnostic markers for abdominal actinomycosis is warranted.