Histologic changes of intraoral free skin flaps

BACKGROUND: It was the purpose of this study to assess the histologic skin changes of free tissue transfers used to reconstruct intraoral defects. METHODS: Patients who were at least 12 months after intraoral free tissue reconstruction were selected for study. A 3-mm punch biopsy of the intraoral portion of the flap was performed and submitted for routine histologic analysis and periodic acid-Schiff (PAS) staining. The adjacent native oral mucosa was also biopsied and served as control. RESULTS: Eight patients (42 to 71 years old) were studied. A variety of skin flaps were employed and included free rectus abdominis (4), radial forearm (2), scapula (1), and osteocutaneous fibula flaps (1). Histologic examination demonstrated that all specimens maintained normal skin architecture and maturation. Adnexal structures were demonstrated in all but one. Acute inflammation in conjunction with diffuse parakeratosis and spongiosis were seen with 4 cases. Fungal forms consistent with Candida species were identified in the stratum corneum by PAS stain in these 4 cases. CONCLUSION: The histologic integrity of skin appears to be maintained in cutaneous free flaps placed intraorally. Previous studies have noted an inflammatory infiltrate in the epithelial tissues of intraorally placed flaps, yet have not commented on the significance of this finding even when it was noted in a chronic setting. Our study is the first to correlate these changes with the presence of fungi. The effect of the acute inflammation and associated fungal forms may suggest the need for chronic therapy and merits further study.