1. THE EFFICACY AND SAFETY OF SHORT PULSE ERBIUM:YAG LASER IN THE TREATMENT OF ACQUIRED MELANOCYTIC NEVI THE EFFICACY AND SAFETY OF SHORT PULSE ERBIUM:YAG LASER IN THE TREATMENT OF ACQUIRED MELANOCYTIC NEVI Mete Baba*, Deniz Seçkin*, Nebil Bal** Başkent University Faculty of Medicine Department of Dermatology* and Pathology** Mete Baba*, Deniz Seçkin*, Nebil Bal** Başkent University Faculty of Medicine Department of Dermatology* and Pathology**

2. No study evaluating the efficacy and safety of an erbium:YAG laser with its small penetration depth and fewer adverse effects in the treatment of acquired melanocytic nevi.

3. Objective To investigate the efficacy and safety of short pulse erbium:YAG laser in the treatment of acquired melanocytic nevi

4. Patients and Methods Patient selection and consent Laser treatment Follow-up Biopsy and histopathologic assessment

5. Inclusion criterias Benign-appearing melanocytic nevi (clinically and dermatoscopically) Nonfacial localization Diameter < 6 mm Flat or just palpable

6. Lazer treatment 1 J 5 Hz 300 µs 2940 nm

7. Follow-up Wound healing Infection Scarring Pigmentary changes

8. Biopsy and histopathologic assessment Biopsy (punch) Histochemical examination H&E Masson-Fontana Immunohistochemical examination S-100 HMB-45

9. Results 14 patients (10 women and 4 men; aged, 21- 38 years; mean, 32.6 years). Four to ten pulses of laser irradiation were sufficient for clinical removal of all nevi Epithelization time was between 7 and 10 days Redness persisted up to 3 weeks in all cases

10. Results-Safety Infection; no Postinflammatory hyperpigmentation; 2 cases Hypopigmentation; 3 cases

11. Results-Efficasy Complete removal; clinically; all of the nevi, and histopathologically, 27 of 28 nevi Nevus cells located in dermis (at a depth of 0,25mm); only one specimen

12. Findings-Histopathology Epidermis; normal Dermis; mild fibrosis ranging between 0.19-0.28 mm (mean, 0.24 mm) Perivascular lymphocyte and eosinophil infiltration; 7 specimens Several melanophages; 4 specimens

14. Discussion-Efficasy The depth of vaporization; 2-4 µm for each 1 J/cm 2, 4 to 10 pulses of erbium:YAG laser irradiation at fluencies between 5.2 and 14.4 J/cm2 are sufficient to remove nevus cells in the dermo-epidermal junction and the upper dermis. In 1 nevus in this study, incomplete

15. Discussion-Safety Melanin pigment içeriği az olan nevüs hücrelerinde yeterli harabiyetin oluşmaması Epidermal pigment yoğunluğunun blokaj etkisi nedeni ile lazer ışınlarının daha alt seviyelerdeki nevüs hücrelerine ulaşamaması

16. Malignant transformation Laser ? Malignant transformation

17. Erbium: YAG lazer; safe and effective