Guideline on the management of melanoma

OBJECTIVE

1. The Guideline for the Management of Melanoma has been developed in an attempt to improve management through the process of locating the best available evidence on which to base decisions. It is expected to help to improve the quality of care. 2. Melanoma remains a common cancer in South Africa. Despite the achievement of earlier diagnosis, it would appear from current statistics that at least 850 people continue to die of melanoma each year. Many of these deaths occur at a younger age than for other solid tumours, so the number of years of life lost due to melanoma exceeds that of many other cancers. It is seen as imperative to maximise effective management of melanoma. 3. Prevention of melanoma has not yet been achieved, and there are no conclusive data to show that current promotion of sun avoidance has substantially altered its incidence. 4. Early detection is an important factor in melanoma management, with diagnosis based mainly on changes in colour, diameter, elevation and border (irregularity of outline) of a skin lesion, asymmetry of a lesion, or a lesion different from other naevi. People at high risk of melanoma should be offered a surveillance programme.

RECOMMENDATIONS

1. All clinicians should be trained in the recognition of early melanoma. 2. If there is doubt about a lesion, the patient should be referred for specialist opinion (if readily available) or a biopsy should be undertaken. Biopsy of a pigmented lesion should be done only on the basis of suspicion of melanoma. Excision with a 2 mm margin is adequate. 3. Prophylactic excision of benign naevi is not recommended. In general, elective lymph node dissection is not indicated. 4. People with high-risk primary melanoma, lymph node involvement and melanoma in unusual sites (e.g. mucosal and disseminated melanoma) should be managed with support from a melanoma centre.

VALIDATION

Melanoma management involves many medical specialties. Guidelines should therefore be developed through a multidisciplinary consensus. The Melanoma Advisory Board consists of a forum of dermatologists, oncologists, plastic surgeons and pathologists.

S100A protein expression in the distinction between lentigo maligna and pigmented actinic keratosis

Lentigo maligna (LM), a type of malignant melanoma in situ, and pigmented actinic keratosis (PAK) may have similar clinical appearances but are different in prognosis and treatment. Diagnosis is established by skin biopsy. In certain cases, microscopic features may be very similar in both entities, making it difficult to determine whether the pigmented atypical cells are keratinocytes or melanocytes. Immunohistochemical markers can be useful for the identification of melanocytes in these cases. There are limitations to the use of some standard immunohistochemistry markers, however. S100 proteins are a varied group of proteins that are of special interest because of their dysregulated expression in neoplastic disorders. Their expression is changed during malignant transformation, progression, and/or metastasis in various cell lines and tumors, including melanomas. Our study analyzed the expression of several of the S100 protein subtypes (S100A2, S100A6, and S100A8/A9 or A12) in 38 LM cases and 44 PAK cases to define their potential value in the distinction between these entities together with their role in the development of early malignant melanoma of the skin. The results showed an upregulation of S100A2 protein in atypical keratinocytes in PAK and in normal keratinocytes adjacent to melanoma cells in LM. There was also an upregulation of S100A8/A9 or A12 protein, as detected by the antibody MAC387, in normal keratinocytes adjacent to both atypical keratinocytes and melanocytes in PAK and LM, respectively. There were statistically significant differences in the level of positive cells and in the pattern of immunoreactivity for anti-S100A2 and MAC387 in each entity, however. Moreover, the findings of our study support the notion that melanocyte-keratinocyte interactions are abnormal in both of these disease entities and may be involved in their progression.

Dermatological perspectives of malignant melanoma

Early recognition and treatment of thin cutaneous melanoma have contributed to a decreased case-fatality rate over the past 60 years. The only known preventive measure for melanoma is sun protection in childhood, which directly affects the number of melanocytic nevi developing as an adult. Additional melanoma risk factors, clinical features, and malignant potential of precursor lesions are discussed. The four major clinicopathologic subtypes of melanoma are described, with recommendations for appropriate biopsy techniques for suspected melanoma. Nationwide skin cancer screenings by dermatologists and greater public awareness of the warning signs of melanoma have enhanced detection of early melanoma, and promoted chances for cure.

Eruptive multiple lentigo-maligna-like lesions in a patient undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing colorectal carcinoma: a lesson for the pathogenesis of malignant melanoma?

Induction of multiple eruptive dermal and atypical melanocytic naevi has frequently been reported in children with malignant haematological diseases and chemotherapy-induced immunosuppression. This is the first report of an adult patient to develop multiple eruptive melanocytic skin lesions while undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing cancer. Our observation adds further evidence to the link between systemic (iatrogenic or intrinsic) immunosuppression and the induction of melanocyte proliferation and transformation.

The precursors of malignant melanoma

The precursors to melanoma are generally considered to be related to nevi of different types. Here we emphasize the dysplastic nevus, the congenital nevus, and lentigo maligna as specific lesions. The dysplastic nevus is discussed not only as a formal precursor but also as a marker of cutaneous melanoma. The clinical and histologic characteristics are outlined, as well as evidence of progression in dysplastic nevi. The congenital nevus is briefly reviewed and emphasis is placed upon clues to malignant degeneration. The concept of lentigo maligna as a precursor as distinct from an in situ phase is detailed.

Atypical lentiginous junctional naevi of the elderly and melanoma

The diagnosis of atypical lentiginous melanocytic naevi in chronic sun-damaged skin is a clinical and pathological challenge. Mottled skin in the elderly is a result of extensive freckling, guttate hypomelanosis, solar lentigines, seborrhoeic keratoses and small dark lentigines. In addition, atypical lentiginous junctional naevi may be seen as isolated lesions and may merge with lesions that are indistinguishable from lentigo maligna. The predominant site distribution of such lesions on the trunk and limbs and the presence of a nested naevoid pattern on biopsy differs from classical lentigo maligna, which develops mainly on the head and neck. Based on case studies combining dermatoscopy with clinical and pathological features, we have found that atypical lentiginous junctional naevi of the elderly may evolve to lentigo maligna and in some cases to small cell (naevoid) melanomas. Such lesions have been previously classified as dysplastic naevi, atypical melanocytic hyperplasia, atypical melanocytic proliferation, atypical lentiginous melanocytic proliferation or premalignant melanosis (McGovern). The current definition of lentigo maligna appears too narrow and the pathway to lentigo maligna in the elderly skin may include a naevoid subset.

[Dermatoscopy of pigmented lesions]

Dermoscopy is a simple to use in vivo method for the early diagnosis of malignant melanoma and the differential diagnosis of pigmented skin lesions. It has been shown to increase diagnostic accuracy over clinical visual inspection in the hands of an experienced physician. This paper is a review of the principles of Dermoscopy as well as recent technological developments.

Evaluation of pigmented lesions of the nail unit

Acquired pigmentary changes of the nail are secondary to a number of etiologies. These include nail matrix nevi; physical induction secondary to trauma; malignant melanoma; nutritional deficiencies; inflammation secondary to lichen planus; endocrine causes such as Addison's disease; or secondary to bacterial, fungal, or viral infections. The most important task faced by clinicians is to distinguish benign from malignant etiologies of nail pigmentation. We will briefly review the various entities that can yield dyspigmentation and their differentiation from melanoma of the nail.

Ultraviolet-Assisted Punch Biopsy Mapping for Lentigo Maligna Melanoma

Lentigo maligna melanoma (LMM) accounts for a substantial incidence of all locally recurrent melanoma. In addition, the head and neck area accounts for 60% to 90% of all LMMs, which has important functional and cosmetic implications. The difficulty in the identification of the true borders of LMM may account for the high incidence of local recurrence. The purpose of this study was to evaluate the efficacy of ultraviolet-assisted punch biopsy mapping to identify clear margins using identified, 2-mm circumferentially arranged punch biopsies at the junction of the pigmented and nonpigmented borders. A retrospective chart review of 20 patients with biopsy-confirmed LMM of the head and neck was performed. Using ultraviolet identification, 2-mm circumferentially arranged biopsy specimens were obtained and sent for formal pathological review, including immunohistochemical staining. The average time for completion of pathological review was 5 to 7 days. If the punch biopsies were positive for lentigo maligna or LMM, punch biopsies were obtained more peripherally. Once clear, margins were obtained and definitive resection was performed. Twenty patients with biopsy-proved LMM were evaluated. Follow-up ranged from 6 months to 3 years (mean follow-up, 1 year). Fourteen patients were cleared after their first series of biopsies, 3 patients required a second series of biopsies, 2 patients required a third session, and 1 patient required a fourth biopsy session. To date, there has been no evidence of recurrence. No patients required reexcision for positive surgical margins. One complication has been local cellulitis of a punch biopsy site requiring a short course of antibiotics. Ultraviolet-assisted punch biopsy mapping of LMM is a safe, well-tolerated, and accurate technique for identifying the true histological margin of LMM. The procedure reduces the need for repeat surgical excisions to obtain clear margins and may decrease the risk for recurrence by mapping accurately the true histological margin.

Treatment of lentigo maligna

Lentigo maligna (LM) is an indolent form of melanoma in situ with the potential to progress to invasive melanoma. Early detection and adequate treatment prior to development to invasive melanoma are essential. Definitive excision with negative margins is currently the treatment of choice for LM. Conventional excision, Mohs micrographic surgical excision, and nonexcisional methods of treatment of LM will be discussed.

Improvement of early recognition of lentigo maligna using dermatoscopy

BACKGROUND

The clinical differentiation between lentigo senilis/initial seborrheic keratosis and lentigo maligna on the face can be difficult.

OBJECTIVE

Our purpose was to determine whether dermatoscopy (eg, skin surface microscopy at 10x magnification) can reliably differentiate between these entities.

METHODS

Dermatoscopic slides of 87 consecutive patients presenting 37 malignant and 50 benign pigmented skin lesions on the face were analyzed with the use of 27 dermatoscopic criteria.

RESULTS

Univariate analysis selected two criteria specific for lentigo maligna: asymmetric pigmented follicular openings and dark (brown or black) rhomboidal structures. Location-specific importance in relation to facial location was attributed to the color "slate-gray, " especially in combination with structures such as dots, globules, streaks, and homogeneous areas. Multivariate analysis (logistic regression model) revealed the 4 most important features to be asymmetric pigmented follicular openings, dark rhomboidal structures, slate-gray globules, and slate-gray dots with a sensitivity of 89% and a specificity of 96%.

CONCLUSION

Three conclusions can be drawn from our study: With a set of 4 dermatoscopic features, early lentigo maligna can be detected with high accuracy; dermatoscopic features on the face differ from criteria used in other locations; and our progression growth model for lentigo maligna delineates the different steps of malignant growth in lentigo maligna.

Amelanotic lentigo maligna melanoma: a unique case presentation

Amelanotic melanomas comprise only 2% of melanomas and are commonly a difficult clinical diagnosis, due to the lack of melanin pigment typically found in melanomas. Even rarer is the amelanotic lentigo maligna, which may have an unusual clinical presentation, such as erythema, pruritus, or edema. Biopsy is the key to diagnosis. Multiple therapies for amelanotic lentigo malignas have been tried, but excision, with margin control (Mohs micrographic surgery-frozen or paraffin sections), remains the treatment of choice.

Cancer precursors

A significant proportion of cutaneous malignancies arise from well-defined precursor lesions that have often been present for many years. This provides an opportunity to reduce rates of skin cancer by recognition and treatment of these lesions. Precursors of keratinocytic malignancy, such as actinic keratoses and Bowen's disease, are extremely common in the older, white population and will frequently be encountered by generalist physicians in the context of examinations for noncutaneous conditions. Less common conditions, such as erythroplasia of Queyrat and nevus sebaceous, are associated with a higher risk of malignant change, and their recognition is therefore imperative. The management of the various precursors of melanoma remains controversial, as the exact risk of malignant transformation of many of these lesions is still unclear.

Optical coherence tomography of the human skin

BACKGROUND

Optical coherence tomography (OCT) is a new diagnostic method for tissue characterization.

OBJECTIVE

We investigated normal and pathologic structures in human skin in several locations to evaluate the potential application of this technique to dermatology.

METHODS

Based on the principle of low-coherence interferometry, cross-sectional images of the human skin can be obtained in vivo with a high spatial resolution of about 15 microns. Within a penetration depth of 0.5 to 1.5 mm, structures of the stratum corneum, the living epidermis, and the papillary dermis can be distinguished.

RESULTS

Different layers could be detected that were differentiated by induction of experimental blisters and by comparison with corresponding histologic sections. Furthermore, OCT images of several skin diseases and tumors were obtained.

CONCLUSION

OCT is a promising new imaging method for visualization of morphologic changes of superficial layers of the human skin. It may be useful for noninvasive diagnosis of bullous skin diseases, skin tumors, and in vivo investigation of pharmacologic effects.

Small cell (naevoid) melanoma: a clinicopathologic study of 131 cases

One hundred and thirty-one small cell melanomas were reviewed with respect to clinical data submitted with each specimen and the histological pattern of each tumour. Of the small cell melanomas, 80% developed in individuals over the age of 50 years. There was a 2:1 male predominance with 58% of the tumours in men occurring on the back. All but one melanoma showed a lentiginous intraepidermal pattern. The dermal component was characterized by cords and nests of hyperchromatic melanocytes associated with interstitial fibrosis. Small cell melanomas may be recognized as thin lesions and are commonly located in chronic sun-damaged skin of elderly individuals. They may represent a special naevoid variant of lentigo maligna melanoma.

Malignant melanoma: differential diagnosis of pigmented lesions

The incidence of melanoma is rising globally despite increased awareness. Familiarity with the clinical signs and certain risk factors for melanoma can result in early recognition, and potentially influence outcome. Unfortunately, there are several other cutaneous tumors, both malignant and benign, that resemble melanoma, and may confuse and possibly delay the diagnosis. This paper discusses the clinical characteristics of melanoma and its most common pigmented simulators.

The starburst giant cell is useful for distinguishing lentigo maligna from photodamaged skin

BACKGROUND

Because lentigo maligna (LM) occurs in areas of the body that are subjected to long-term UV radiation (UVR), it may be difficult to distinguish atypical melanocytes in LM from the pleomorphic, atypical melanocytes in actinically damaged skin.

OBJECTIVE

The purpose of this study was to determine whether the presence of multinucleated melanocytes would help to make this distinction.

METHODS

A total of 89 cases of LM were reviewed for the presence or absence of multinucleated melanocytes and, if present, the maximum number of nuclei was recorded. As controls, 107 elliptical excisions of basal cell carcinoma or squamous cell carcinoma were randomly selected. The tips of the ellipses were reviewed for the presence or absence of multinucleated melanocytes.

RESULTS

Multinucleated melanocytes with a "starburst" appearance, because of their prominent dendritic processes, were present in 85% of LM cases but in only 21% of sun-damaged control specimens (p < 0.00001; odds ratio [OR] = 22.6; 95% confidence interval [CI] = 10.6-47.9). The sensitivity and specificity of starburst giant cells (SGCs) in the diagnosis of LM was 85% and 78%, respectively. The maximum number of nuclei per SGC ranged from 2 to 30 in the LM cases (mean, 6.8 +/- 6.1) and from 2 to 6 in the controls (mean, 2.7 +/- 1.1) (p < 0.001). If only those SGCs with more than two nuclei are considered, 76% of cases but only 8% of controls contained SGCs (p < 0.00001; OR = 35.3; CI = 15.2-81.7). Similarly, 64% of cases and 3% of controls had SGCs with more than three nuclei (p < 0.00001; OR = 61.8; CI = 18.1-210.6).

CONCLUSION

The SGC is a useful indicator for the diagnosis of LM. The diagnosis of LM is also more likely as the number of nuclei in SGC increases.

[Malignant melanoma in dermatoscopical picture]

Dermatological investigation offers a more precise clinical diagnosis of malignant melanoma in 20-30% of cases. It gives a correct visualization of melanocytic structures up to dermatoepidermal junction in ten fold magnification. A less distinct picture can be obtained from medium corial structures. Lentigo maligna melanoma and superficially spreading melanoma can be well distinguished from other pigmented lesions. Dermatoscopy offers an inspirative view between a clinical and microscopical picture plane.

Recurrent lentigo maligna invading a skin graft successfully treated with Mohs' micrographic surgery

Lentigo maligna (LM) is a pigmented lesion occurring on sun-exposed skin that may become lentigo maligna melanoma (LMM). The tumor can behave in an aggressive fashion, causing significant cosmetic disfigurement, often extending significantly further than the clinical margin. Complete surgical excision is the treatment of choice. We describe a 74-year-old woman with a large LM of the left cheek, upper and lower eyelids, and preauricular skin that had recurred twice. The tumor was removed using Mohs' micrographic surgery (MMS) with rush permanent sections and was found to infiltrate extensively the split-thickness skin graft that had been placed five years earlier. LM can invade and replace a skin graft. Although destructive modalities and conventional surgery are recommended by some authors, MMS offers the greatest likelihood of cure, the ability to examine nearly 100 percent of the surgical margins, and maximal tissue sparing. Complete excision of LM at its earliest recognition may prevent invasive LMM and will limit cosmetic disfigurement.

Lentigo maligna and lentigo maligna melanoma

Lentigo maligna (LM) is a pigmented lesion that occurs on the sun-exposed skin, particularly the head and neck areas, of an older patient. The lesion increases in size and at some point, often many years after its onset, may become lentigo maligna melanoma (LMM). For this reason, most authors consider LM a form of melanoma in situ. Treatment includes surgical or destructive modalities; the preferred form of therapy is surgical removal. Histopathologic features include a proliferation of atypical melanocytes along the basal layer of the epidermis and adnexal structures. This article discusses the clinical, histopathologic, and epidemiologic features of LM. The prognosis and treatment of LM are reviewed. Although the lifetime risk of the development of LMM is unclear, LMM is discussed briefly.

[Malignant lentigo]

Lentigo maligna (LM) is a premalignant skin alteration, which may progress to lentigo maligna melanoma (LMM). LM usually appears as a small dark brown spot in the head and neck region. Over some years it may gradually enlarge to palm size and the colour become more motley. Histologically many atypical melanocytes are seen in the basal layer of the epidermis and along the adnexal structures, as well as there being dermal elastosis and a lymphohistiocytic inflammatory infiltrate in the superficial dermis. Excision should be performed as soon as the diagnosis is made to avoid more extensive excision, transplantation and development into LMM later on. If transformation of LM into LMM occurs, often after many years, fast growth, increased pigmentation and sometimes a nodular formation are observed. Histologically, the atypical melanocytes have invaded the dermis.

Melanoma: detection and management

The author discusses the features of very early melanoma and looks at the importance of change as a characteristic for diagnosing it. The use of the dermatoscope is also discussed in relation to the early diagnosis of melanomas and other lesions. Identification of the high risk patient and appropriate methods of surveillance for such patients are also presented.

Familial cutaneous melanoma and two-mutational-event modeling

BACKGROUND

According to the Knudson two-mutational-event theory, two mutations at a genetic locus may be required for the development of some cancers. Persons who have inherited a defect in one chromosome and therefore require only one more mutation for cancer development are at a higher risk of manifesting cancer at a younger age than persons without an inherited mutation, who need two acquired "hits." This difference allows one to distinguish familial and sporadic types of the same malignancy by evaluating age of disease onset.

METHODS

To study the role of inheritance in the etiology of familial cutaneous melanoma, characteristics of patients with familial versus nonfamilial melanoma were analyzed according to the Knudson two-mutational-event model.

RESULTS

The familial versus nonfamilial graphs, based on age of diagnosis, did not support this model. However, there was a statistically significant earlier age of diagnosis for patients with familial melanoma. Melanoma thickness was less (i.e., earlier cancer at possibly younger age) for patients with a positive versus a negative family history. Conversely, linear regression, after adjusting for tumor thickness, showed that patients with hereditary melanoma still manifested earlier ages of diagnosis of melanoma compared with sporadic patients.

CONCLUSIONS

Genetic patterns other than the two-step model, additional family-related factors, patient-physician sensitization due to a family history, or a combination of these factors might explain this age difference. More complex multistep modeling of the data may be helpful in better characterizing the genetic patterns of cutaneous melanoma.