Principles and guidelines for surgeons: management of cutaneous malignant melanoma. European Society of Surgical Oncology Brussels

Knee Desmoplastic Melanoma, an Uncommon Tumor, Disguised as a Malignant Peripheral Nerve Sheath Tumor: A Case Report and Review of the Literature

Desmoplastic melanoma is a rare and distinct subtype of cutaneous melanoma, it presents diagnostic challenges due to the lack of specific clinical features and overlapping histopathological characteristics with other malignancies, which necessitate careful clinicopathological correlation and advanced immunohistochemical profiling. While surgical excision remains the cornerstone of treatment, advances in precision medicine, particularly immune checkpoint inhibitors, have shown promise in improving outcomes for unresectable and metastatic desmoplastic melanoma. We present a case study involving a 52-year-old woman misdiagnosed with a malignant peripheral nerve sheath tumor and later identified as desmoplastic melanoma through re-evaluation of histopathological and immunohistochemical findings. The patient underwent surgical resection followed by adjuvant radiotherapy and showed favorable locoregional development.

Primary Melanoma: from History to Actual Debates

PURPOSE OF REVIEW

This review describes the long scientific background followed to design guidelines and everyday clinical practice applied to melanoma patients. Surgery is the first option to cure melanoma patients (PTS) at initial diagnosis, since primary cutaneous lesions are usually easily resectable. An excisional biopsy of the lesion, with minimal clear margins, can be obtained in the vast majority of cases. Punch biopsies may be proposed only in case of large lesions located on specific cosmetic or functional areas like the face, extremities, or genitals where a mutilating complete resection would not be performed without prior histological diagnosis.

RECENT FINDINGS

After the histologic confirmation of melanoma, definite surgical excision of the scar and surrounding tissue is planned, to obtain microsatellite free margins. The width of these margins has been identified following the results of several clinical trials and it is either 1 or 2 cm, depending on the Breslow thickness of the primary tumor. Following the latest staging system proposed by the American Joint Cancer commission (AJCC), a sentinel node biopsy (SNB) is usually performed in case of a primary lesion > 0.8 mm thickness or for high-risk thinner lesions, if no evidence of nodal involvement has been identified clinically or radiographically. Surgical management of primary melanoma is well established. There is debate on the optimal surgical margins for 1-2 mm melanomas. There are specific considerations for special primaries (bulky, extremity, mucosal). Sentinel node (SN) evaluation does not improve survival, but is routinely used as staging.

Improving outcomes in patients with melanoma: strategies to ensure an early diagnosis

Patients with thin, low-risk melanomas have an excellent long-term prognosis and higher quality of life than those who are diagnosed at later stages. From an economic standpoint, treatment of early stage melanoma consumes a fraction of the health care resources needed to treat advanced disease. Consequently, early diagnosis of melanoma is in the best interest of patients, payers, and health care systems. This review describes strategies to ensure that patients receive an early diagnosis through interventions ranging from better utilization of primary care clinics, to in vivo diagnostic technologies, to new "apps" available in the market. Strategies for screening those at high risk due to age, male sex, skin type, nevi, genetic mutations, or family history are discussed. Despite progress in identifying those at high risk for melanoma, there remains a lack of general consensus worldwide for best screening practices. Strategies to ensure early diagnosis of recurrent disease in those with a prior melanoma diagnosis are also reviewed. Variations in recurrence surveillance practices by type of provider and country are featured, with evidence demonstrating that various imaging studies, including ultrasound, computed tomography, positron emission tomography, and magnetic resonance imaging, provide only minimal gains in life expectancy, even for those with more advanced (stage III) disease. Because the majority of melanomas are attributable to ultraviolet radiation in the form of sunlight, primary prevention strategies, including sunscreen use and behavioral interventions, are reviewed. Recent international government regulation of tanning beds is described, as well as issues surrounding the continued use artificial ultraviolet sources among youth. Health care stakeholder strategies to minimize UV exposure are summarized. The recommendations encompass both specific behaviors and broad intervention targets (eg, individuals, social spheres, organizations, celebrities, governments).

Long-term follow-up for melanoma patients: is there any evidence of a benefit?

As the incidence of melanoma and the number of melanoma survivors continues to rise, optimal surveillance strategies are needed that balance the risks and benefits of screening in the context of contemporary resource use. Detection of recurrences has important implications for clinical management. Most current surveillance recommendations for melanoma survivors are based on low-level evidence with wide variations in practice patterns and an unknown clinical impact for the melanoma survivor.

Variability in melanoma post-treatment surveillance practices by country and physician specialty: a systematic review

There are no evidence-based guidelines for the surveillance of patients with melanoma following surgical treatment. We carried out a systematic review to identify by country and physician specialty the current stage-specific surveillance practices for patients with melanoma. Three major medical indices, MEDLINE, the Cochrane Library database, and Scopus, were reviewed to identify articles published from January 1970 to October 2011 that included detailed information about the surveillance of patients with melanoma after the initial surgical treatment. Data on surveillance intervals and recommended evaluation were extracted and categorized by country and, when reported, physician specialty. One hundred and four articles from 10 countries and four physician specialties (dermatology, surgical oncology, medical oncology, and general practice) fulfilled the inclusion criteria, including 43 providing specific patient-level data. The articles showed a wide variation with respect to the surveillance intervals and recommended evaluations. The variation was greatest for patients with stage I disease, for whom the follow-up frequency ranged from one to six visits per year during years 1 and 2 after treatment. All four physician specialties agreed that for years 1-3, the follow-up frequency should be four times per year for all patients. For years 4 and 5, surgical oncologists recommended two follow-up visits per year, whereas general practitioners, dermatologists, and medical oncologists recommended four visits per year. Recommended imaging and laboratory evaluations were most intense in the UK and most minimalist in the Netherlands. Although general practitioners did not recommend routine laboratory or imaging tests for surveillance, all other specialties utilized both in their surveillance practice. Self skin-examination was recommended for surveillance in all countries and by all practitioner specialties. There are significant intercountry and interspecialty variations in the surveillance of patients with melanoma. As the number of melanoma survivors increases, it will be critical to examine the benefits and costs of various follow-up strategies to establish consensus guidelines for melanoma post-treatment surveillance.

Significance of serum S-100B in melanoma patients before and after sentinel node biopsy

BACKGROUND AND OBJECTIVES

The clinical utility of the tumor marker serum S-100B has been described in determining prognosis, for early diagnosis of recurrence and for disease monitoring in melanoma patients. Sentinel node biopsy is increasingly used as staging procedure for patients with clinically localized melanoma. The aim of this study was to determine the value of serum S-100B in melanoma patients before and after sentinel lymph node biopsy.

METHODS

S-100B values were measured prior to sentinel node biopsy in 89 patients and during follow-up (median 41 months; range 7-73 months) in 88 patients. The detection limit is < or =0.08 microg/L. In our laboratory levels of 0.16 microg/L and above are classified as increased.

RESULTS

Twenty-four patients had tumor-positive sentinel nodes, 65 had tumor-free sentinel nodes. The median S-100B value prior to the operation was < or =0.08 microg/L for all patients. Sensitivity and specificity of S-100B to predict the tumor-status of the sentinel node were 13% and 98%, respectively. Eighteen patients developed a melanoma-related recurrence. Sensitivity for early diagnosis of recurrence was 55% and 33%, respectively for patients with a positive versus a negative sentinel node. Specificity was 100% in both patient groups.

CONCLUSIONS

S-100B is not useful in predicting the tumor-status of the sentinel node, and questionable for early diagnosis of recurrence afterwards. Elevation of serum S-100B is highly specific for melanoma recurrence.

Diagnosis of melanoma in the elderly and surgical implications

The diagnosis of primary melanoma is mainly related to the precocity on which a patient is referred to the specialist, but in elderly patients this may present some peculiar characteristics, one is anatomical, a typical melanoma of the face, the lentigo maligna melanoma and the second is attitudinal, the fact that elderly patients often do not refer a changing cutaneous lesion to a doctor until becoming symptomatic. The therapeutic approach has to be discussed with an anaesthesiologist if the procedure has to be conducted under general anaesthesia or with a cardiologist if under local anaesthesia. Once there are no contraindications medically, a similar oncological approach should be proposed without any reduction in radicality due to the elderly age.

Radioguided sentinel lymph node biopsy in patients with malignant cutaneous melanoma: the nuclear medicine contribution

As for other solid tumors, malignant cutaneous melanoma drains in a logical way through the lymphatic system, from the first to subsequent levels. Therefore, the first lymph node encountered (the sentinel node) will most likely be the first to be affected by metastasis, and a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Sentinel lymph node biopsy distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, and those with metastatic involvement who might benefit from additional therapy. This procedure represents a significant advantage as a minimally invasive procedure, considering that only an average 20% of melanoma patients with Breslow thickness between 1.5 and 4 mm harbour metastasis in their sentinel node(s) and are therefore candidates to elective lymph node dissection procedures. The cells that originate cutaneous melanomas are located between dermis and epidermis, a zone that drains to the inner lymphatic network in the reticular dermis, in turn to larger collecting lymphatics in subcutis. Therefore, the optimal modality of interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is through intradermal/subdermal injection. (99m)Tc-labeled colloids in various size ranges are equally adequate for radioguided sentinel lymph node biopsy in patients with cutaneous melanoma, depending on local experience and availability. For melanomas located in the midline area of the head, neck, and trunk, particular consideration should be given to ambiguous lymphatic drainage, which frequently requires interstitial administration virtually all around the tumor or surgical scar from prior excision of the melanoma. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the sites of the node(s). The sentinel lymph node should have a significantly higher count than that of background (at least 10:1 intraoperatively). After removal of the sentinel node, the surgical bed must be reexamined to ensure that all radioactive sites are identified and removed for analysis. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is about 98% in institutions where a high number of procedures are performed, approaching 99% when combined with the vital blue dye technique. The procedure is becoming the standard of care for patients with cutaneous melanoma because of its high prognostic value that has led to include the procedure in the most recent version of the TNM staging system.

New diagnostic techniques in staging in the surgical treatment of cutaneous malignant melanoma

The emphasis of the research on the surgical treatment of melanoma has been on the resection margins, the role of elective lymph node dissection in high risk patients and the value of adjuvant regional treatment with hyperthermic isolated lymph perfusion with melphalan. Parallel to this research, new diagnostic techniques, such as Positron Emission Tomography and the introduction of the sentinel lymph node biopsy with advanced laboratory methods such as immuno-histochemical markers, and reverse transcriptase polymerase chain reaction, have been developed to facilitate early detection of metastatic melanoma. The role of these new techniques on the staging and surgical treatment of melanoma is discussed in this paper.

Surgical techniques of melanoma and sentinel node biopsy

The adequacy of surgical treatment of melanoma patients is the most important milestone in the natural history of the disease, once the diagnosis has been confirmed. Surgery plays a fundamental role in the initial stages of the disease, ie, to remove the primary lesion and to excise accurately the locoregional metastases. On the contrary, the impact of a surgical indication to treat distant metastases has never been confirmed in a prospective study; thus, there are no standard guidelines and it represents a decision to be discussed with each individual patient.

Vulvar melanoma: is there a role for sentinel lymph node biopsy?

BACKGROUND

The objective of this study was to evaluate the author's recent, preliminary experience with the sentinel lymph node procedure in patients with vulvar melanoma and to compare this experience with treatment and follow-up of patients with vulvar melanomas who were treated previously at their institution.

METHODS

From 1997, sentinel lymph node procedure with the combined technique (99mTechnetium-labeled nanocolloid and Patente Blue-V) was performed as a standard staging procedure for patients with vulvar melanoma with a thickness > 1 mm and no clinically suspicious inguinofemoral lymph nodes. For the current study, clinicopathologic data from all 33 patients with vulvar melanoma who were treated between 1978 and 2000 at the University Hospital Groningen were reviewed and analyzed.

RESULTS

From January 1997 until December 2000, identification of sentinel lymph nodes was successful in all nine patients who were referred for treatment of vulvar melanoma. Three patients underwent subsequent complete inguinofemoral lymphadenectomy because of metastatic sentinel lymph nodes. In follow-up, groin recurrences (in-transit metastases) occurred in two of nine patients, both 12 months after primary treatment. Both patients had melanomas with a thickness > 4 mm and previously had negative sentinel lymph nodes. There was a trend toward more frequent groin recurrences in patients after undergoing the sentinel lymph node procedure (2 of 9 patients) compared with 24 historic control patients (0 of 24 patients; P = 0.06). Five of 33 patients developed local recurrences: Two patients had groin recurrences, and 11 patients developed distant metastases. Twelve patients died of vulvar melanoma. Seventeen patients with a median follow-up of 66 months (range, 9-123 months) are currently alive (overall survival rate, 52%).

CONCLUSIONS

Although the numbers were small, this study showed that the sentinel lymph node procedure is capable of identifying patients who have occult lymph node metastases and who may benefit from lymphadenectomy for locoregional control and prevention of distant metastases. However, the data also suggest that the sentinel lymph node procedure may increase the risk of locoregional recurrences (in-transit metastases), especially in patients with thick melanomas. The potential role of the sentinel lymph node procedure as an alternative method of lymph node staging in patients with vulvar melanoma needs further investigation only within the protection of clinical trials and probably should be restricted to patients with melanomas with intermediate thickness (1-4 mm).

[Managing cutaneous melanoma]

Cutaneous melanoma represents the main cause of death among skin cancers. Early diagnosis gives, for the time being, the only possibility for high rate of curative treatment. Diagnosis is based on pathological findings, and at primary tumor stage. Breslow thickness of the lesion is the best prognostic index. At local stage of the disease, treatment is precisely codified by international recommendations and consensus conferences. Follow-up after surgical treatment is also well codified. Treatment of lymph node invasion or metastatic disease is, on the other hand, less codified. Despite recent advances, especially in immunotherapy, treatment of advanced stages of melanoma remains difficult.