Sentinel node-guided evaluation of drainage patterns for melanoma of the helix of the ear.

The head and neck region, and especially the ear and its helix, is notorious for its ambiguous pattern of lymphatic drainage. Therefore, the primary nodal drainage basins in melanoma of the helix of the ear are often unpredictable. The aim of the study was to examine the value of sentinel lymph node biopsy in melanoma of the helix of the ear and to describe the natural history of the disease. Fifteen consecutive patients (14 men) with primary melanoma of the helix of the ear (median thickness, 1.2 mm; range, 0.7-10.0) underwent preoperative lymphoscintigraphy, followed by intraoperative lymphatic mapping, using blue dye in combination with a hand-held gamma probe and sentinel lymphadenectomy. The melanomas were characterized by low mitotic rate, low lymphocytic infiltrate, low spontaneous-regression rate, and mostly epitheloid cell type. In one patient, preoperative lymphoscintigraphy failed to demonstrate the draining nodes. The sentinel lymph nodes were identified and retrieved in all patients during surgery. In 13 patients (87%), they were found in the upper jugular lymphatic basin (level IIA); none were found in the retroauricular region. All sentinel lymph nodes were tumor-negative. At a median follow-up of 39 months (range, 12-73), all 15 patients were disease-free. In conclusion, sentinel lymph node biopsy for helix melanoma is an excellent alternative to elective lymph node neck dissection and superficial parotidectomy, with a high success rate and low morbidity. Melanoma of the helix of the ear has an indolent natural history.