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

Abstract

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.

Challenges in Diagnosis and Management of External Ear Melanoma Case Report and Literature Review

“…Particularly, total or partial amputation of the ear could render a patient unable to wear eye glasses or some hearing aids. These aggressive recommendations dominated the literature for over a decade until larger series were reported [18,19]. Recent studies, have demonstrated that these melanomas can be treated conservatively avoiding aggressive amputations and advocating more moderate treatment strategies including Mohs surgery, composite "wedge" excision of skin and cartilage-sparing surgery [20].…”

A systematic review on external ear melanoma

“…14 Despite the great variability, identification of the SLN is possible in >90% of cases. 9,20,29 All the studies reported a predominance of drainage at level II, and Shpitzer et al 9 always found at least one SLN at levels II or III in 15 melanomas of the helix 9 ( Table 1).…”

“…Several authors support the idea that these patterns are highly unpredictable, 4,6,14,15,20,21,25,27,29 but only a few studies focus on the lymphoscintigraphy and the drainage patterns of the external ear. Nine studies report information about the regional lymph nodes, 4,6,9,14,16,20,24,25,29 but only four of them describe the exact location of the identified sentinel node according to Robbins' topographic classification 31 of the cervical node levels. 6,9,14,16 These studies confirm that the drainage pattern of the external ear is variable and unpredictable; in Peach et al's series of 111 lymphoscintigraphy, lymphatic drainage occurred in a retrograde, antegrade, or transaural pattern, although never contralaterally.…”

“…Nine studies report information about the regional lymph nodes, 4,6,9,14,16,20,24,25,29 but only four of them describe the exact location of the identified sentinel node according to Robbins' topographic classification 31 of the cervical node levels. 6,9,14,16 These studies confirm that the drainage pattern of the external ear is variable and unpredictable; in Peach et al's series of 111 lymphoscintigraphy, lymphatic drainage occurred in a retrograde, antegrade, or transaural pattern, although never contralaterally. 14 Despite the great variability, identification of the SLN is possible in >90% of cases.…”

“…2e9 The external ear presents peculiar characteristics with respect to anatomy and lymphatic drainage: the presence of a thin skin and of a cartilaginous framework requires a specific approach for tumor resection and reconstruction; lymphatic drainage e as for other head and neck regions e is unpredictable and often reaches multiple basins. 4,9 Furthermore, there is no agreement on the biological behavior of melanoma of this region: some authors claim a better prognosis and propose less invasive treatments, 8,9 while others consider external ear melanoma more aggressive. 2 As a consequence, its treatment is not standardized, which often differs from standard treatment for melanomas of other regions.…”