The Histological Study of Accessory Tragus: A Comparison of Vertical Sections with Transverse Sections

ABSTRACT

BACKGROUND: Accessory tragi contain a central core of cartilage, which is the most important pathological factor, but often are misdiagnosed as soft fibroma/hair follicle nevi if sections cannot show a central core of cartilage. OBJECTIVES: The purposes of this study were aimed at comparing transverse sections with vertical sections and demonstrating the value of transverse sections about histological diagnosis for accessory tragus. METHODS: We studied 14 cases of patients with accessory tragi. All cases were totally excised and all 16 biopsy specimens (bilateral in 2 cases) were obtained. We classified these biopsy specimens into two groups regarding the removal of cartilage.All specimens were vertical or transverse seiral sectioned and we compared these histologic findings with established histologic diagnostic criteria which Satoh et al. reported. RESULTS: On the specimens of group 1 in which there was cartilage, subcutaneous prominent connective tissue framework whirling around cartilage could be observed on all transverse sections, but was not always present on vertical sections. Prominent connective tissue framework and pilosebaceous units with circular arrangement of eccrine glands were simultaneously in the center of transverse sections regardless of the presence of cartilage. CONCLUSIONS: In this study, transverse sections showed all diagnostic histologic important features for accessory tragus presence of central cartilage, prominent subcutaneous connective tissue framework, and various degree of pilosebaceous unit, especially with circular arrangement of eccrine glands. So transverse sectioning could be a useful method for accurate histological diagnosis of accessory tragi regardless of the removal of cartilage when doing excisional biopsy.