Objective: To highlight the important clinical and histological features of sinonasal blue naevi.
Methods: A case of blue naevus of the nasal cavity is described (including endoscopic and histological pictures) and the existing literature is reviewed.
Results: There have been five reported cases (including the presented case). Clinically, sinonasal blue naevi are heavily pigmented lesions that are small and asymptomatic. Histopathologically, blue naevi exhibit heavily pigmented dendritic melanocytes that are never abnormal in form.
Conclusion: Blue naevus should be a differential diagnosis for pigmented lesions within the sinonasal cavity, despite its rarity. It may be initially suspected by its small size and asymptomatic nature. However, histological examination is required for definitive diagnosis, looking for the key microscopic features described above.