PURPOSE: The aim of this study was to perform a histological analysis of the effect of a ytterbium-doped fiber (YDF) laser on oral buccal mucosa tissue in vivo to simulate its effect on the mucosa of the lower urinary tract. METHODS: A total of 90 8-week-old Sprague-Dawley rats were anesthetized with urethrane (1.2 g/kg intraperitoneally). A pre-specified inner buccal mucosal site was irradiated with a YDF master-oscillator power amplifier (MOPA) system for 60 seconds, with output power settings of 0.5, 1, and 2 W, respectively, in 3 treatment groups. Specimens of irradiated tissue were harvested at 2 hours, 24 hours, 2 weeks, and 4 weeks after irradiation. The tissue specimens were stained with hematoxylin and eosin for histological analysis. RESULTS: In the group treated with 0.5 W, basal cell elongation and vacuolization were observed at 2 hours and 24 hours after treatment, respectively. No evident injury was observed after 2 or 4 weeks. The group treated with 1 W presented partial basal layer separation, and even complete epidermal ablation, within 2 hours. At 24 hours after laser treatment, new capillaries on an edematous background of fibroblasts and myofibroblasts, as well as profuse infiltration of the neutrophils to the basal layer, were observed. Collagen deposition and reepithelization were observed in specimens taken 2 weeks and 4 weeks after treatment. The group treated with 2 W presented bigger and deeper injuries at 2 hours after irradiation. Meanwhile, subepidermal bullae with full-thickness epidermal necrosis and underlying inflammatory infiltrate were observed 24 hours after treatment. The presence of fibrous connective tissue and collagen deposition were observed 2 weeks and 4 weeks after the treatment. CONCLUSIONS: To our knowledge, this is the first report regarding the effect of a YDF laser on living tissue. Our study demonstrated that the typical histological findings of the tissue reaction to the YDF MOPA apparatus were very similar to those associated with thermal injuries. The extent and degree of tissue damage increased proportionally to the output power.
Animals ; Capillaries ; Collagen ; Connective Tissue ; Eosine Yellowish-(YS) ; Fibroblasts ; Hematoxylin ; Mouth Mucosa* ; Mucous Membrane ; Myofibroblasts ; Necrosis ; Neutrophils ; Prostatic Hyperplasia ; Rats* ; Rats, Sprague-Dawley ; Urinary Tract* ; Wound Healing

The Sézary syndrome is a leukemic form of cutaneous T-cell lymphoma characterized by the presence of erythroderma covering at least 80% of the body-surface area, lymphadenopathy, and the presence of clonally related neoplastic T cells with cerebriform nuclei (Sézary cells) in the blood, skin, and lymph nodes. Hypereosinophilia can be caused by hematologic malignancy with clonal abnormality, which is often associated with Sézary syndrome. Sézary syndrome has rarely been reported in Korea. However, hypereosinophilia in the Sézary syndrome has not been reported in Korea. Here, we report a case of 75-year-old man with hypereosinophila, erythroderma, and cutaneous T-cell lymphoma which was finally diagnosed as Sézary syndrome.