Sentinel lymph node mapping in melanoma of the ear

A Systematic Review of Surgical Management of Melanoma of the External Ear

Background

Historically, external ear melanomas have been treated aggressively, due to early perceptions suggesting they had poor prognosis and aggressive biological behavior. More recent evidence has not supported these notions.

Methods

We completed a complete review of the literature involving malignant melanoma of the external ear. We then completed a quantitative analysis on seventy-three cases from 8 reports that contained case-level data, assessing factors that influence recurrence, and assessing characteristics of the melanomas based on histological subtype. Baseline and outcomes data for all 20 studies were then compiled but not statistically evaluated.

Results

In our subanalysis, patients who had recurrence were significantly more likely to have had wedge resection versus wide-local excision, and those with no recurrence were more likely to have undergone wide local excision. Nodular tumors had significantly greater thickness. Overall, conservative excisions provided excellent outcomes.

Conclusions

Conservative treatment for external ear melanoma produces satisfactory outcomes. There is no evidence to support the use of radical amputation and little evidence to support the removal of cartilage or perichondrium. Sentinel lymph node biopsy is warranted only with positive nodes. There is no role for elective neck dissection. The roles for chemo/radiation therapy are unclear and guidelines for other cutaneous melanomas should be followed.

A systematic review on external ear melanoma

BACKGROUND

External ear melanoma accounts for only 1% of all cutaneous melanomas, and data on its optimal management and prognosis are limited.

AIM

We aim to review the literature on external ear melanoma to guide surgeons in the treatment of this uncommon and peculiar pathology.

MATERIALS AND METHODS

A systematic review of English language studies on ear melanoma published from 1993 to 2013 was performed using the PubMed electronic database. Data on epidemiology, oncological treatment (tumor resection and regional lymph nodes management), and reconstruction were extrapolated from selected papers.

RESULTS

The total number of patients was 858 (30 studies). The helix was the most common location (57%); superficial spreading melanoma was the most common histopathological subtype (41%). The mean Breslow thickness was 2.01 mm, with 88% of stage I-II patients. Sentinel lymph node biopsy was performed in 45% of patients, with 8% of positive nodes. Available data on its prognosis are fragmentary and contrasting, but the Breslow thickness appears to be the main prognostic factor. There is a tendency towards reduced resection margins and preservation of the underlying perichondrium and cartilage. Local flaps are the most popular reconstructive option.

CONCLUSION

To the best of our knowledge, this systematic review presents the largest data series on external ear melanoma. There is no general agreement on its surgical management, but a favorable prognosis seems to justify the tendency towards conservative treatments.

Surgical reconstruction after subtotal ear resection in malignant melanoma of the ear

Surgery in malignant melanoma of the external ear often leads to substantial defects where reconstruction poses a difficult challenge. We describe an option of a one-step ear reconstruction after subtotal ear resection in malignant melanoma surgery. In a patient with a high-risk melanoma of the helical rim, a wide local excision was performed. Because of a metastasis-suspect lymph node in the parotid gland, surgery included asservation of the sentinel lymph node, neck dissection and parotidectomy. A complete reconstruction of the ear was achieved using a bilobed flap from the retroauricular and neck region with acceptable cosmetic and functional results by one-step surgery. One micrometastasis was detected in the nuchal region but not in the marked sentinel lymph node. An adequate one-step ear reconstruction as described may also be performed to the benefit of patients with high-risk melanomas, allowing early adjuvant therapy.

Melanoma of the ear: prognostic factors and surgical strategies

BACKGROUND

The ear's specific anatomical and lymphatic characteristics impose special requirements on the treatment of melanoma of the ear.

OBJECTIVES

The aim of this prospective study was to define prognostic factors for melanoma of the ear and to evaluate surgical strategies for excision margins, histological evaluation and sentinel lymph node biopsy (SLNB) in order to achieve better cosmetic and functional results.

PATIENTS AND METHODS

One-hundred and sixty-one patients with stage I/II melanoma of the external ear were treated in the Department of Dermatology, University of Tuebingen, from March 1976 to March 2004 (median follow-up 62 months). Malignant melanoma of the external ear represented 3% of the stage I/II cutaneous melanomas and 20% of the stage I/II head and neck melanomas recorded in the Melanoma Registry of the Department of Dermatology at the University of Tuebingen. Twenty of 42 lentigo maligna melanomas (LMM) underwent conventional histological evaluation, 22 underwent complete three-dimensional histology of excision margins (3D histology) in a paraffin-technique, i.e. micrographic surgery. SLNB was performed in 28 patients with melanomas thicker than 1.0 mm. Clinical, histological and surgical risk factors were evaluated by univariate and multivariate analysis.

RESULTS

The median thickness of the tumours in the present study was 1.08 mm (mean 1.51 mm; range 0.18-8.50 mm), and the median excision margins were 11.0 mm (mean 12.61 mm; range 2.0-31.0 mm). The 3-year disease-specific survival rate was 98%, and the 3-year recurrence-free survival rate was 83%. Tumour thickness and invasion level were the only risk factors significant for disease-specific survival. Tumour thickness, location of the tumour and extent of excision margins were independently significant risk factors for recurrence-free survival. LMMs removed surgically with accompanying 3D histology were thicker than those examined by conventional histology (median 0.93 mm vs. 0.83 mm). The use of surgery with 3D histology, i.e. micrographic surgery, made it possible to reduce the excision margins (median 5 mm vs. 10 mm) without an increased risk of recurrence. Two of 29 SLNBs were positive (6.9%). There were six preregional recurrences after negative SLNB and one after positive SLNB. None of the patients who underwent SLNB died of melanoma-related causes during the observation period.

CONCLUSIONS

This is the largest series of ear melanomas reported so far. The overall survival depended only on the tumour thickness and Clark level of invasion. Local recurrence was more frequent with smaller excision margins, but this did not influence the overall survival. Smaller excision margins under 3D-histological control did not carry an increased risk of local recurrence. Our results do not permit conclusions regarding the prognostic impact of SLNB for patients with melanoma of the ear.

Tumours of the external ear and temporal bone

Symptoms such as hearing impairment, tinnitus, or a disturbance in sense of balance can generally be attributed to non-neoplastic causes, such as otitis media, otosclerosis, or trauma. Less commonly, auricular signs and symptoms are the result of non-neoplastic and neoplastic space-occupying lesions. The external ear can be the site of development of squamous carcinomas and basal-cell carcinomas; the middle ear and inner ear can host metastatic deposits, and primary squamous carcinomas and adenocarcinomas. Most auricular malignant diseases occur in adulthood; only the rhabdomyosarcomas of the middle ear arise in children. Most malignant diseases of the auricular apparatus are treated by a combination of surgery (commonly including radical excision of temporal bone), radiotherapy, and chemotherapy.

Evaluation of nodal patterns for melanoma of the ear

Treatment of malignant melanoma of the external ear presents unique challenges. Because of the significant debate regarding the efficacy and validity of using sentinel lymph node mapping for the treatment of ear melanomas, data for a population of patients with melanomas of the ear who underwent surgical excision and reconstruction were reviewed to determine the efficacy of sentinel node mapping. A retrospective chart review of cases treated by a single surgical oncologist was performed. All patients who were treated for malignant melanomas and required reconstruction of the external ear by the plastic surgical service between 1995 and 2001 were identified. Nineteen patients were selected, of whom nine underwent sentinel node mapping. The average age of the patients was 65.2 years. Evaluation of melanoma depth, medical history, surgical margins, lymph node metastasis, and recurrence was performed. Lymphoscintigraphy with technetium-99-sulfur colloid and 1% Lymphazurin (isosulfan blue; Zenith Parenterals, Rosemont, Ill.) demonstrated widely variable lymphatic drainage patterns. The lower tail of the parotid gland and the upper cervical area were the two most common locations. The average number of sentinel nodes identified and removed was 3.7. The average Breslow thickness for these patients was 2.3 mm. None of these patients demonstrated micrometastatic disease in their sentinel nodes. The most common reconstructive procedure after surgical resection was the use of rotational advancement flaps. Localization of radioactivity, as detected with external technetium-99 scanning, was the most reliable method for detection of the sentinel lymph node basins and the individual nodes. The average value for the primary injection site was 8375 counts per second, and the average value for the nodes removed was 973.5 counts per second. Of the nine patients who underwent sentinel lymph node mapping, only one, with an initial lesion depth of 5 mm, developed a local recurrence. The average follow-up period in this study was 21 months (range, 12 to 79 months). All patients in this study were evaluated at least 1 year after the initial surgical resection. Patients were monitored by the same surgical oncologist every 3 months for the first 2 years. Little can be found in the literature regarding the efficacy of sentinel node biopsies for ear melanomas. Larger studies are indicated; however, it seems that this method is practical for designing therapeutic methods for patients with melanoma of the ear.

Changing surgical therapy for melanoma of the external ear

BACKGROUND

The purpose of this study was to evaluate the prognostic variables and clinical ramifications of melanoma of the ear.

METHODS

A retrospective chart review of patients treated since 1985 at the Mayo Clinic in Scottsdale, AZ, and Rochester, MN, identified 78 patients with complete follow-up.

RESULTS

Of these 78 patients, 68 (87%) were men; the mean age was 64 years (range, 23-87 years). Melanoma thickness averaged 1.7 mm (range,.2-7.0 mm). Treatment of the primary melanoma included wedge resection (59%), Mohs resection (14%), partial amputation (11%), skin and subcutaneous resection with perichondrium preservation (9%), and total amputation (7%). Nineteen patients underwent an elective lymph node dissection, and lymph node metastases were found in seven (37%). Two patients presented with clinically positive lymph nodes. Sentinel lymph node biopsy was performed in 10 patients. After a mean follow-up of 55.7 months, 10 patients (13%) had local recurrence, 9 patients (12%) had regional recurrence, and systemic metastases had developed in 17 patients (22%). Tumor thickness, lymph node metastases, and local recurrence significantly affected systemic recurrence.

CONCLUSIONS

The treatment of malignant melanoma of the external ear should follow current standard guidelines, which require wide local excision with negative margins. Sentinel lymph node biopsy can be used to identify patients with lymph node metastases who are at high risk of recurrence.

[Surgical therapy of malignant melanoma of the external ear]

METHOD

The data from our patients of the last 10 years were evaluated in relation to survival and recurrence.

RESULTS

Very different surgical therapy-in some cases due to refusal of the therapy suggested-was performed in eight patients (including wedge shaped excision as well as ablation of the auricle). The mean survival ranged from 40 months up to the present. One patient died due to a local recurrence and regional and systemic metastases. One patient experienced local recurrence but is still well 16 months after he underwent surgical revision. Two patients died independently of the tumor.

DISCUSSION

Comparison of our results with those of other studies confirms that the extent of the applied resection has of minor effect on recurrence and survival for this disease. Tumor thickness is the most important independent prognostic factor.