Tracheal Actinomycosis Presenting as a Pseudotumor: A Case Report

Tracheal actinomycosis is a rare bacterial infection that can mimic the appearance of a tumor, known as a pseudotumor, according to a case report published in Cureus. The condition involves the growth of Actinomyces bacteria in the trachea, which can lead to airway obstruction and diagnostic challenges because the resulting mass often resembles malignant growths on imaging and during endoscopic exams.

The report describes a patient presenting with a tracheal mass that appeared to be a tumor. Upon further clinical investigation and biopsy, the mass was identified as actinomycosis. This infection is caused by anaerobic or microaerophilic bacteria, primarily from the Actinomyces genus, which typically reside in the oral cavity and gastrointestinal tract.

Diagnostic Challenges of Tracheal Pseudotumors

According to the Cureus report, tracheal actinomycosis is exceptionally rare and frequently misdiagnosed due to its presentation as a pseudotumor. A pseudotumor is a mass that looks like a tumor on radiological scans or during a bronchoscopy but is actually caused by inflammation, infection, or other non-cancerous processes.

The bacteria cause chronic granulomatous inflammation, which creates a firm, dense mass of tissue. In the trachea, this mass can narrow the airway, causing symptoms such as shortness of breath, persistent cough, or stridor. Because these symptoms and the physical appearance of the mass overlap with tracheal cancer, clinicians may initially suspect malignancy.

Pathology and Bacterial Transmission

Actinomyces bacteria are commensal organisms, meaning they naturally exist in the human body without causing disease under normal conditions. The Cureus case report notes that the infection typically occurs when these bacteria breach the mucosal barrier, often following dental procedures, oral trauma, or chronic poor oral hygiene.

Once the bacteria enter the deeper tissues, they can cause abscesses and “sulfur granules,” which are small, yellow colonies of bacteria characteristic of actinomycosis. In the case of tracheal involvement, the bacteria migrate from the oral cavity or lungs into the tracheal wall, triggering an immune response that leads to the formation of the pseudotumor.

Treatment and Clinical Management

The management of tracheal actinomycosis requires a combination of targeted antimicrobial therapy and, in some cases, surgical intervention to clear the airway. According to the report, high-dose penicillin G is the gold standard for treating Actinomyces infections, often administered over several months to ensure the complete eradication of the bacteria due to their slow growth rate.

Alternative treatments for patients allergic to penicillin include the use of tetracyclines or combinations of other antibiotics. The report emphasizes that early and accurate diagnosis via biopsy and bacterial culture is critical to avoid unnecessary radical surgeries that would be required for actual tracheal tumors.

The case underscores the importance of considering infectious etiologies when a patient presents with a solitary tracheal mass, particularly if the patient has a history of oral health issues or dental trauma.