Laryngeal granuloma: characteristics of the covering epithelium

The purpose of the present study was to evaluate the biological behaviour of the marginal epithelium, that proliferates and eventually covers laryngeal granulomas, and to reveal the applicability of the recently re-introduced Ljubljana classification when reporting reactive epithelial hyperplastic lesions. A retrospective clinical and histomorphological analysis was performed on 149 laryngeal granuloma biopsies. Epithelial changes were classified according to the Ljubljana classification into normal epithelium; simple, abnormal, or atypical hyperplasia; and carcinoma in situ. Atrophic epithelium, not evaluated separately in the Ljubljana classification, was additionally assessed. Simple hyperplasia was found in 98 cases (65.8 per cent), abnormal hyperplasia in seven (4.7 per cent), atrophic epithelium in 24 (16.1 per cent), and normal squamous epithelium in 20 (13.4 per cent). Atypical hyperplasia and carcinoma in situ were not observed. The results of our study clearly showed that the proliferation of the covering epithelium mostly in the form of simple hyperplasia, is entirely reactive and therefore reversible. No epithelial hyperplastic lesions were found that were previously described to be associated with an increased risk of malignant alteration, namely atypical hyperplasia and carcinoma in situ. However, since an initial growth of an invasive malignant neoplasm might macroscopically imitate the appearance of laryngeal granuloma, a histological examination in all aetiological forms of laryngeal granulomas is required. By clearly discerning the benign nature of epithelial changes in laryngeal granulomas, the recently re-evaluated and further formulated Ljubljana classification may also influence the clinical handling of patients.