[Disseminated pulmonary actinomycosis - an unusual presentation]

Area of Science:

• Infectious Diseases
• Pulmonology
• Microbiology

Background:

• Actinomycosis is a rare, chronic infection caused by commensal anaerobic Gram-positive bacteria (Actinomyces spp.).
• It often presents with variable clinical courses, mimicking neoplastic diseases due to its chronicity.
• Endogenic infections are typical, originating from commensal bacteria in the oropharynx, genitourinary, and gastrointestinal tracts.

Observation:

• A 56-year-old male presented with unusual pulmonary actinomycosis.
• The manifestation included bilateral disseminated lung nodules and systemic symptoms, initially treated for tuberculosis.
• Diagnosis was confirmed via histologic evaluation of a surgical lung biopsy specimen.

Findings:

• The patient exhibited an uncommon presentation of pulmonary actinomycosis.
• Initial antitubercular treatment was ineffective, underscoring the diagnostic challenge.
• Histologic confirmation was crucial for accurate diagnosis.

Implications:

• This case emphasizes the importance of considering actinomycosis in the differential diagnosis of disseminated lung nodules, even after initial treatment for other conditions.
• Prompt and accurate diagnosis, confirmed by histology, is essential for effective management.
• Successful treatment with a 7-month antibacterial regimen led to significant clinical and radiological improvement, demonstrating the curability of pulmonary actinomycosis.