Non-Tuberculous Laryngeal Granulomas: Systematic Review and Case Series.

Background: Submucosal laryngeal lesions may pose diagnostic uncertainty and mimic tumours. Although mycobacterium tuberculosis is the leading cause, non-tuberculous granulomas arise from multiple aetiologies. This paper presents a systematic review and case series to elucidate a diagnostic process.

Methods: Systematic review of MeSH terms pertaining to 'granuloma' and 'larynx' was conducted. Inclusion criteria were granulomatous disease on histological examination, located in the larynx, of any non-malignant aetiology. Exclusion criteria were disease located outside the larynx, of a non-autoimmune or non-infectious aetiology. Risk of bias was assessed with JBI case series and ROBIN-I tools. Case series data were obtained from a retrospective review of medical records.

Results: Of 2621 studies, nine papers with 30 patients were included. Infectious causes include leishmaniasis, histoplasmosis, laryngoscleroma, cryptococcosis, sporotrichosis and botryomycosis. Our case series proposes sarcoidosis as an autoimmune cause. Repeat biopsies are indicated when non-diagnostic, and autoimmune testing is non-specific. Four patients in our case series had non-diagnostic biopsies through microlaryngoscopy, requiring open biopsies to exclude malignancy.

Conclusion: Autoimmune and infectious causes of laryngeal granulomas require a high index of suspicion to guide management. International collaboration may aid the creation of a diagnostic pathway for laryngeal biopsies for granulomatous disease.