Colonic Actinomycosis Presenting One Year After Partial Sigmoid Colectomy.

Area of Science:

• Medical Microbiology
• Gastroenterology
• Surgical Pathology

Background:

• Actinomycetes are commensal bacteria in the oral and gastrointestinal tracts.
• Abdominal actinomycosis commonly affects the ileocecal region and appendix.
• Pathogenicity arises from invasion of injured mucosal tissues.

Observation:

• A case of recto-sigmoid colon actinomycosis is presented.
• Symptoms included abdominal pain and diarrhea one year post-sigmoid colectomy.
• Colonoscopy revealed a partially obstructing polypoid mass.

Findings:

• Histopathology confirmed actinomycosis with characteristic sulfur granules and filamentous organisms.
• Microscopic findings included granulation tissue, acute inflammation, and abscess formation.
• The mass was located in an unusual site for abdominal actinomycosis.

Implications:

• Abdominal actinomycosis can manifest in diverse locations, challenging diagnosis.
• This case underscores the need to consider actinomycosis in post-surgical patients with persistent gastrointestinal symptoms.
• Early and accurate diagnosis is crucial for effective treatment of actinomycosis.