Multicentricity of Type II First Branchial Cleft Anomalies.

Abstract

First branchial cleft anomalies (FBCAs) are the result of misguided embryologic development of the external auditory canal, resulting in a partial duplication of the structure. A recent consensus statement by the International Pediatric Otolaryngology Group (IPOG) reclassified lesions based on anatomic location rather than the classic germ cell layer classification. Type I FBCAs are external and superficial to the parotid fascia, and type II FBCAs are juxtaposed to, or involving, the parotid gland. The consensus statement supports extensive resection to prevent recurrence. We hypothesized that type II FBCAs may be multicentric. The objective of this study was to search for histological evidence of this characteristic which, if present, supports the recommendation of the IPOG consensus for extended surgical resection. Archived histopathologic resections of type II FBCAs were evaluated for satellite lesions or filamentous tracts off the main lesion indicating respiratory epithelium and extension of pathology beyond the typical resection. Pathologic analysis identified 22 archived tissue specimens with adequate histology to evaluate for the presence of FBCA tissue in the parotid gland. 6/22 (27.3%) demonstrated FBCA tissue external to the main lesion or multiple epithelial rests of similar tissue outside the primary lesion consistent with pathology beyond the primary cyst itself. The results support the notion that type 2 FBCAs are extensive and can be multicentric. These findings also support the clinical experience and recommendation of the IPOG consensus statement for a more extensive dissection and removal of surrounding tissue in the effort to best prevent recurrence.