The relation between breslow thickness and sentinel lymph node in malignant melanoma

Malignant melanoma(MM) is the tumor of melanocytes which mostly originates from the skin(1). Vertical thickness of the tumor (Breslow thickness) is the most important prognostic factor in primary cutaneous malignant melanoma (2-4). MM generally spreads by lymphatics and the first lymph node that it drains to is named as sentinel lymph node. Sentinel lymph node biopsy (SLNB) is a staging procedure done for finding out if the tumor has spread to the lymph nodes. This procedure has less complications when compared to the elective lymph node dissection. SLNB is not recommended to melanomas which have Breslow thickness less than 1.00 mm. We aimed to find out the relation between the sentinel lymph node positivity and Breslow thickness in this study. Approval was obtained from Ethics Council of Bezmialem Vakif University for the master thesis. The study was achieved retrospectively and prospectively on 74 patients who were admitted to Bezmialem Vakif University Medical Faculty Hospital, Dermatology Department and Vakif Gureba Hospital, Dermatology Clinic between the years 1995-2015. The relation between the sentinel lymph node positivity and Breslow thickness and the other histopathologic parameters were statistically calculated. Breslow thickness, mitosis count and lymphatic invasion were significantly related to sentinel lymhph node positivity (p<0.05). The sentinel lymph node was negative in the patients who had Breslow thickness less than 1.00 mm and most of the SLN positivity was found in the patients who had Breslow thickness more than 4.00 mm. Sentinel lymph node biopsy is a procedure that is done for staging and for estimating the prognosis and it also helps us to decide about the treatment(75). In the literature, although SLNB is recommended only to the patients who have Breslow thickness more than 1.00mm, according to the AJCC guidelines(updated in 2009), it should be recommended to stage T1b patients whose Breslow thicknesses are less than 1.00mm with ulceration or mitosis count more than 1/mm2. Key words: malignant melanoma, breslow thickness, mitosis count, sentinel lymph node biopsy, lymphatic invasion