Laryngeal Actinomycosis: A Rare Cause of Dysphonia

A 93-year-old African American male with chronic kidney disease presented with a 6-month history of progressively worsening dysphonia and odynophagia. He reported no history of similar complaints or previous otolaryngologic surgeries. He denied significant alcohol use, ever smoking, recent travel, or exposure to sick contacts. His otolaryngologic examination was unremarkable except for flexible laryngoscopy which revealed nodular leukoplakia of the anterior true vocal folds bilaterally with involvement of the anterior commissure (Figure 1). Biopsy revealed squamous mucosa with hyperkeratosis on hematoxylin-eosin stain, and Gram stain identified gram-positive bacterial colonization consistent with actinomyces (Figure 2). A 6-month course of renally dosed amoxicillin was initiated for outpatient treatment of laryngeal actinomycosis. Unfortunately, after 3 weeks of treatment, the patient was admitted to the hospital for dyspnea and ultimately diagnosed with omental carcinomatosis with lung metastasis. A subsequent transition to hospice care prompted the family to withdraw treatment for the laryngeal actinomycosis. No further follow-up was pursued.

Figure 1.

Flexible laryngoscopy reveals a nodular leukoplakia of the bilateral anterior true vocal folds with involvement of the anterior commissure (circle).

Figure 2.

Gram stain reveals strongly gram-positive, nonspore forming, filamentous bacilli.

Actinomyces is a gram-positive, anaerobic bacterium and normal commensal inhabitant of human oral flora. ¹ Though the pathogenesis of infection remains unclear, trauma (from radiotherapy) and immunocompromised states likely contribute. ² Actinomycosis predominantly affects the cervicofacial region; however, primary actinomycosis of the larynx remains a rare presentation with fewer than 30 cases reported in the literature. ³

Patients with laryngeal actinomycosis often present with dysphonia accompanied by dysphagia or odynophagia. ⁴ Absence of cervical lymphadenopathy is characteristic. ⁵ A draining cervical sinus should create a high-index of suspicion. ⁶ Grossly, laryngeal actinomycosis appears as a nodular mass on the vocal folds, and the surrounding tissue often remains unaffected. ⁴ Imaging findings may be useful to rule out other pathologies but are nonspecific to laryngeal actinomycosis. ⁷ The initial clinical presentation may be confused for laryngeal carcinoma, papilloma, reactive posttraumatic changes, or other infectious etiologies. ^4,8

Diagnosis of Actinomyces ultimately relies on histopathology with Gram stain identifying strongly gram-positive, nonspore forming bacilli. Methenamine silver stains can be used to highlight the filamentous bacteria. ⁹ Cultures are rarely useful due to frequent contamination and slow growth. ⁵

Standard treatment consists of long-term (greater than 1 month) administration of a penicillin-based monotherapy, though no treatment guidelines exist. ^4,5 Tetracycline, erythromycin, and clindamycin (reserved for penicillin allergies) may be useful, as well. ^5,6 Patients who can complete the prolonged course of antibiotics should experience full recovery without high risk of recurrence. ⁴ Surgery is reserved for cases with abscess, fistula, or concomitant carcinoma. ^{4, 8} Those with persistent or untreated disease can expect local disease progression. ⁶

Laryngeal actinomycosis is a poorly described entity of the head and neck; nevertheless, otolaryngologists should be familiar with its presentation, diagnosis, and management to avoid unnecessary invasive treatment approaches.