Surgical Excision Including Margins

Evolving treatment of primary melanoma has transitioned from radical surgical treatment to more appropriate excisional margins. This trend has been especially true for lesions of the head and neck where disfigurement is important to the patients. Early descriptions of the surgical treatment of melanoma recommended 5-cm margins around the primary lesion including fascia and muscle, regional lymphadenectomy, and sometimes all subcutaneous tissues in between. The current practice of more reasonable margins has not changed survival. In meta-analysis of randomized controlled trials comparing narrow and wide margins for resection, there was no difference in death, disease-free survival, or recurrence when narrow (1–2 cm) margins were used compared with wider (3–5 cm) margins. In addition to equal oncologic outcomes, the smaller margin significantly decreased the need for split-thickness skin graft reconstruction or delayed reconstruction. The data for margins of 1 cm on melanomas less than 1 mm in depth are supported, but it is unclear if a 1-cm margin for thicker melanoma is sufficient. Table 1 shows the typical margins of resection used at the authors’ institution for lesions not involving the head and neck. Studies comparing the risk of regional metastasis based on preservation versus inclusion of the fascia in the surgical resection surprisingly have shown no difference in outcome. Therefore, current standards of case include dissection only down to the fascia unless the tumors have already evaded through the fascial layer.

Special care is required for lentigo maligna melanomas due to difficulties in determining lesion margins. The role of first determining lesion margins using boundary biopsy techniques (such as the 2-blade square technique described later) allows for fewer recurrences and more satisfactory reconstructions. Desmoplastic melanomas, which are locally more aggressive, require more extensive surgical margins of 3 to 5 cm.

Sentinel Lymph Node Biopsy/Completion Lymph Node Dissection

In all melanoma patients with lesions at a Breslow depth greater than 1 mm, consideration must be made for evaluation of the lymph node basins. It is well established that increasing depth of invasion is associated with increased risk of distant disease. Metastatic disease to regional lymph nodes has been demonstrated in even thin lesions. At a minimum, all patients require physical examination of all lymph node basins including the cervical, axillary, epitrochlear, popliteal, and inguinal drainage basins, regardless of primary disease location. For patients with lesions greater than 1 mm in depth and clinically node-negative disease, lymphoscintigraphy with sentinel lymph node biopsy must be performed. The Multicenter Selective Lymphadenectomy Trial-I demonstrated the prognostic value of sentinel lymph node biopsy. In addition, this study showed that for intermediate thickness melanomas (1.2–3.5 mm in depth), sentinel lymph node biopsy with completion lymphadenectomy in patients with a positive sentinel node improved overall survival.

In younger patients, consideration for sentinel node biopsy with lesions less than 1 mm may be warranted because there is suggestive evidence that they have a higher frequency of regional metastatic disease. The only potential exception is for the severely medically compromised patient with a negative clinical examination who would not be a candidate for completion lymph node dissection due to significant surgical risk. Any patient with clinically positive lymph nodes should undergo fine-needle aspiration for confirmation of metastatic disease with subsequent lymph node dissection if testing is positive. Patients with inconclusive fine-needle aspirations should be evaluated for excisional lymph node biopsy. For patients with thin melanomas (<1.0 mm in depth), recommendations are currently being reviewed with attempts to identify pathologic characteristics that may predict high-risk thin lesions, including mitotic rate or primary tumor location. The data remain controversial for lesions between 0.75 and 1.00 mm. Lesions less than 0.75 mm should not undergo sentinel node biopsy because it does not seem to be a predictor of outcome. It is still unclear as to what additional surgical care is needed for a small focus of micrometastatic disease in the sentinel lymph node; however, the current standard of care is for completion lymph node dissection for any positive sentinel lymph node biopsy. Future data from the Multicenter Selective Lymphadenectomy Trial-II should help address some of these issues.

Resection of Metastasis

Melanoma is one of the few malignancies for which surgical resection of metastasis has been shown to prolong survival in selected patients. In addition to excision of recurrences at the primary site, in-transit disease, and lymph node drainage basins, surgical excision should be considered for distant disease if clinically isolated and appropriate. This approach is particularly true in the head and neck, where control of local disease will prolong the quality of survival. It is the authors’ institutional practice to perform radical resection of recurrent disease when clinically feasible unless there is extensive distant metastasis. For extensive extremity in-transit disease that is not amenable to surgical resection, the patient should be evaluated for a limb perfusion or infusion technique.

Reconstruction

After surgical excision with pathologically cleared margins, reconstruction can be performed in either an immediate or staged fashion, depending on location. For example, hand and ear melanomas may require immediate reconstruction to avoid infected critical structures such as tendons or auricular cartilage. Reconstruction should be aimed at closure of the defect without compromising the ability for surveillance. Melanoma is prone to local recurrence even after clear surgical margins. For superficial lesions on areas with increased tissue laxity, surgical excision in an elliptical fashion with layered closure is preferred. After identification of the lesion, the appropriate surgical margins are marked around the lesion. This mark is then turned into an elliptical incision using roughly a 3:1 length to width ratio designed parallel to the relaxed lines of tension. Alternatively, one can remove the lesion with the marked circular margin and then start to close the defect, with excision of any remaining standing cutaneous deformities. Both of these primary closure techniques are ideal from a reconstructive perspective and a future surveillance standpoint.

On the face and extremities, however, primary closure following excision may not always be possible due to a lack of soft tissue laxity or distortion of critical structures. Local skin flaps including the keystone, V-Y advancement, rotational, and rhomboid flaps, are popular techniques that allow closure of extremity defects without skin grafting. Larger areas, or when local reconstructive options are not available, can also be treated with split-thickness skin grafting. The role of bilaminar dermal regenerative templates (Integra) is an advance in the surgical treatment of melanoma. Using bilaminar dermal regenerative template on the resection defect allows the surgeon to clear the margins in high-risk lesions or provide a collagen base to cover defects, particularly lesions in the scalp. Extensive reconstruction including muscle flaps or free flap is generally not indicated except in rare circumstances.

Scalp

Surgical management of melanoma on the scalp is challenging because reconstruction options are limited to skin grafts. Moreover, tumor recurrence, particularly in males, makes scalp flaps undesirable. Unlike in other areas of the body, the authors believe that surgical margins for scalp melanoma should include resection of the galea aponeurotica down through the pericranium. This action forces the surgeon to use skin substitutes such as Integra to populate the bone with fibroblasts so that delayed skin grafting can occur. The delay in reconstruction allows the pathologist to assess the surgical margin and determine if the sentinel node is positive, thus requiring regional lymphadenectomy. Integra occasionally fails, and successful reconstruction requires bone burring and reapplication. It is important to counsel patients that melanoma of the scalp and neck have a high rate of mortality compared with other sites, when controlled for other prognostic factors.

Face

Lentigo maligna (melanoma in situ) and lentigo maligna melanoma occur frequently on the face, and are challenging because clear surgical margins are hard to achieve. Margins frequently are positive for atypical junctional melanocytic hyperplasia, which is a precursor of melanoma. The surgical management of melanoma on the face is challenging because of the close proximity of multiple structures that are not easily sacrificed with the typical margins. The 2-blade “square” technique has been shown to allow for peripheral margin control before resection on the face. For atypical junctional melanocytic hyperplasia or melanoma in situ, the 2-blade square technique for peripheral control allows for improved margin control and the ability to perform formal excision with immediate reconstruction. In this technique, parallel incisions are made around the lesion typically by a dermatologic cutaneous surgeon. The incisions are then closed while a pathologic review is conducted. Further resection is then performed if necessary until margins are negative. The patient then undergoes a secondary excision of the entire square with immediate reconstruction. Standard techniques for facial reconstruction are then used, including skin grafting, local tissue rearrangement, and local-regional flaps. At the authors’ institution, the 2-blade square technique is most commonly employed for lesions on the nose, cheek, eyelid, and neck.

Ears

The ear is the site of primary melanoma in 7% to 20% of head and neck melanomas, with approximately half occurring on the helix. Surgical management previously included standard margins based on Breslow depth. However, initial narrower margins of surgical resection with staged reconstruction after negative pathology may be necessary. Depth of excision should be down to and including the cartilage in most cases. Wedge excision leaves good surgical options for reconstruction. Wedge excision also allows for further excision if the margins are close. The authors have found management of auricular melanoma with this technique to be successful from both an oncologic and a reconstructive outcome. Atypical junctional melanocytic hyperplasia and melanoma in situ can be managed with preservation of the cartilage and temporary coverage. If final pathology reveals no invasive disease, then reconstruction using skin grafting or local flaps is performed. Previous recommendations for complete or partial auriculectomy are now reserved only for recurrent or extensive disease. Lymphatic drainage of the ear is often to the parotid basin. Positive sentinel lymph node requires regional lymphadenectomy in the area of drainage. Experience clearly is necessary to perform these procedures. Most commonly, superficial parotidectomy and anterior neck dissections are required for positive sentinel nodes. The drainage occasionally is into the posterior neck, and level V nodes must be dissected.

Eyelid

Primary melanoma of the eyelids is seen in substantial volume only in large melanoma centers. Given the small, but important amount of soft tissue in the periocular region, recommended excisional margins tend to be smaller, with no clear decrease in survival benefit. Margins of 5 mm have been suggested for lesions with Breslow depth less than 1 mm. However, lesions greater than 2 mm in depth likely require 10 mm to decrease local recurrence. After achieving local control, standard techniques for eyelid reconstruction are employed. Specialized oculoplastic surgeons may be involved in reconstruction, based on local referral patterns.

Hands

Melanomas on the hand occur in distinct anatomic locations: dorsal skin, palmar skin, digits, or subungal nail. For dorsal hand skin, surgical management requires resection down to the paratenon, and requires immediate reconstruction with skin grafts or flaps to prevent tendon exposure. Lesions of the palm are best treated by radical excision and skin grafting. Superficial lesions of the digit (Breslow depth less than 1 mm) can be treated with radical excision, and flap or skin graft reconstruction. In contrast, invasive lesions of the digit (Breslow depth greater than 1 mm) require amputation at one joint proximal to the melanoma along with sentinel lymph node biopsy. For the index finger, ray amputation should be discussed with the patient, given the improved functional outcome and ability for the middle finger to be used for pinching. Subungal melanoma is a unique problem because it is impossible to determine the Breslow depth without excisional biopsy. Moreover, the quality of the biopsy, due to the anatomy of the nail matrix, makes interpretation of the depth circumspect. In these cases, the authors favor amputation at the level of the distal interphalangeal joint.

Toes

Melanoma of the feet can be divided into lesions of the dorsal surface, plantar surface, or digits. Dorsal foot melanomas can either be skin grafted or closed linearly, depending on the laxity of the skin. Melanoma of the plantar surface of the foot represents a particular challenge. Skin grafts do not heal well in this area, particularly if the patient has diabetes. Application of Integra after resection of acrolentiginous lesion is a good solution, because it allows time to clear the margins and provides a collagen mat for a subsequent skin graft. Lesions of the digits are best treated with amputation; however, superficial lesions (<1.0 mm) can be treated with Integra and skin grafting to preserve the aesthetic appearance of a 5-digit foot. Postoperative ambulation may also be improved with preservation of the great toe treated with reconstruction rather than amputation.

Genitalia

Melanoma of the female genitalia is rare, occurring in 0.23% of all melanomas. The most common site for primary disease is the vulva, with histology typically of a mucosal lentiginous type. Staging specifically for vulva melanoma has not been clearly established. Current surgical recommendations are based on standard Breslow depth determined margins, with radical surgery including vulvectomy, used only in exceptional cases. Early lesions that present with melanoma in situ usually can be treated with resection and skin grafts. Vaginal melanomas are advanced and typically have a nodular histologic type. Actual tumor size and not tumor thickness is the best predictor of long-term survival.

Although rare, melanoma of the male genitalia is frequently located on the penis, with case reports existing for primary scrotal melanoma. Although surgical standards for care have not been fully evaluated, it is the authors’ practice to perform partial or total penectomy for invasive penile melanoma. Thin lesions can be managed with wide local excision and skin graft reconstruction. Scrotal melanoma is rarer, and managed with wide local excision and scrotal reconstruction as necessary. Sentinel lymph node biopsy is performed for all lesions with Breslow depth greater than 1 mm.