Histologic characterization of human scarred vocal folds

Abstract

Vocal fold scarring remains a significant problem. Although several animal models have been developed to improve our understanding of the histopathology, the histologic features of scarred human vocal folds have rarely been reported. The present case studies aimed to define the histologic changes of scarred human vocal folds caused by cordectomy or cordotomy. Ten patients with the scarred vocal folds were involved in this study. Nine patients with early glottic cancer underwent endoscopic cordectomy, and one patient underwent superficial cordotomy for idiopathic scar. The postcordectomy or cordotomy scar was biopsied or resected 3-13 months after the original procedure. After confirming absence of any tumor in cancer patients, the remaining specimens were used in the present study. Histologic examination investigated deposition of extracellular matrix (ECM) including collagen, elastin, hyaluronic acid (HA), fibronectin, and decorin in the lamina propria of the scarred vocal folds. There was a wide range of variation in the deposition of ECM in scarred vocal folds. Excessive and disorganized collagen deposition was observed in most cases that had undergone deep resection of the lamina propria, whereas deposition of collagen was mild and well organized after superficial resection. Decorin was retained in all cases after superficial cordectomy or cordotomy, but varied after deep resection. Deposition of elastin, HA, and fibronectin varied regardless of depth of injury. Histology of scarred vocal folds may vary with degree of injury and individual healing mechanism.