Can flat-type brownish microlesions in the orohypopharynx be followed up without biopsy or endoscopic resection?

Background Narrow-band imaging ( NBI) is useful for detecting superficial oropharyngeal lesions. However, the diagnostic and treatment guidelines for NBI are not established. The aim of the present study was to evaluate the treatment strategy for these microlesions. Methods From October 2008 to September 2009, 68 flat-type brownish microlesions were observed in the orohypopharynx using NBI. Lesions were examined via magnifying NBI ( M-NBI) and followed up without biopsy or endoscopic resection for >12 months. To clarify the characteristics, lesions were compared with the endoscopic characteristics of flat-type lesions diagnosed by biopsy and endoscopic resection as squamous cell carcinoma and high-grade intraepithelial neoplasia. Results The average diameter of the 68 lesions was 1.6 mm (range, 0.5-5 mm). At the 1-year follow up, 19 lesions had disappeared. No size increases or morphological changes wereobserved among 49 lesions followed for >1 year. At 2 years, 10 patients had dropped out and 11 lesions had disappeared. No changes were observed among 28 lesions followed for >2 years. Of the flat-type lesions as squamous cell carcinoma and high-grade intraepithelial neoplasia, a distinct border and irregular distribution of atypical vessels were observed in all cases using M-NBI. These findings were observed in two of 68 flat-type brownish microlesions during follow up. Conclusion Although there is some possibility of squamous cell carcinoma or high-grade intraepithelial neoplasia, flat-type microlesions of ≤5 mm diameter in the orohypopharynx may be followed for up to 2 years without biopsy or endoscopic resection. [ABSTRACT FROM AUTHOR]