Evaluation of narrow band imaging in the assessment of laryngeal granuloma

Laryngeal granulomas belong to common complications following trans-oral laser microsurgery (TLM). The aim of this study was to evaluate NBI in the differentiation between granuloma-like lesions and local tumor recurrence. 154 consecutive patients after TLM due to early laryngeal cancer were enrolled. In the group, a monthly follow-up including NBI endoscopy was performed. Moderate and severe dysplasia, carcinoma in situ and invasive cancer were defined as positive histology, laryngeal granuloma and other benign laryngeal lesions as negative histology and premalignant lesions as suspicious histology. In 47/154 (31%) cases, granuloma-like lesion (GLL) was found. Patients with GLL were divided into two groups based on the NBI classification. In all patients, the microvascular pattern in NBI was compared with the final histology. In group A, with suspicious, perpendicular vessels, 13/13 (100%) samples were positive. In group B, with normal vascular pattern 3/34 (9%) samples were positive and 31/34 (91%) samples were negative. There was a significant correlation between the positive NBI vascular pattern and the final histology (p = 0.00001). Sensitivity, specificity, accuracy of NBI were as follows: 81%, 100%, 94%, respectively.Based on our results, NBI can reliably differentiate between postoperative laryngeal granuloma and local tumor recurrence. In such a manner, this method is very helpful in the follow-up of tumor patients.