Flexible Endoscopic Biopsy: Identifying Factors to Increase Accuracy in Diagnosing Benign and Malignant Laryngopharyngeal Pathology.

Summary Objectives To assess the influence that several factors, such as the amount of obtained biopsies, difficult procedures, biopsy site and the experience of the attending physician, have on accuracy of flexible endoscopic biopsy (FEB). Materials and methods 203 FEB procedures for benign or malignant laryngopharyngeal lesions were prospectively included. During the procedure, three representative biopsies (macroscopically containing vital tumor tissue and not only necrosis or healthy tissue) were obtained. The accuracy of each biopsy was separately analyzed. Difficulties during the procedures leading to failure of acquiring three representative biopsies were recorded and classified into tumor, patient and procedural factors. Histological results of FEB were defined correct when consistent with clinical context, additional biopsies or Positron emission tomography-computed tomography (PET-CT) revealed equivalent pathology, or the lesion was stable or resolved in >6 months follow-up. Results The first representative biopsy yielded a correct diagnosis in 65% of the cases. After the second representative biopsy, 78% was correctly diagnosed. The contribution of the third and fourth representative biopsies to accuracy was 3%. The overall accuracy of FEB was 85%. Difficult procedures were more likely to result in misdiagnosis, whereas biopsy site or experience of the attending physician did not influence results. Conclusions FEB was accurate in diagnosing laryngopharyngeal lesions when at least two representative biopsies were obtained. Accuracy of FEB could be further improved by limiting possible constraints during the procedures, for example by selecting, informing, and anesthetizing patients carefully.