3. MALIGNANT MELANOMA: 3. MALIGNANT MELANOMA A tumour arising from melanocytes of the basal layer of the epidermis Less commonly – uveal tract (eye) and meningeal membranes


INCIDENCE: INCIDENCE Global incidence is rising relentlessly In NI, the incidence rate of melanoma is increasing faster than any other tumour 1996 – 181 new cases of malignant melanoma On average 28 deaths due to melanoma each year


RISK FACTORS FOR MELANOMA: RISK FACTORS FOR MELANOMA Large numbers of benign naevi Freckles Clinically atypical naevi Severe sunburn Early years in a tropical climate Family history of MM


PATIENT EDUCATION: PATIENT EDUCATION


FAMILY HISTORY: FAMILY HISTORY The majority of MMs occur in a sporadic pattern 2-10% of patients presenting with MM give a positive family history In part this may be due to the inheritance of specific MM susceptibility genes eg, CDKN2A on chromosome 9 Other reasons for familial clustering are atypical naevi and sun exposure


NAEVI: NAEVI CONGENITAL NEVI – occur in 1% of newborns. Tend to be large. Increased risk of MM ACQUIRED MELANOCYTIC NAEVI – 30-50% of all MMs arise in pre-existing naevi. ↑nos of naevi=↑risk MM ATYPICAL NAEVI / SYNDROME –association between a familial occurrence of MM and an atypical naevus phenotype


SUNSCREENS: SUNSCREENS Have been promoted as protective agents But this is not supported by epidemiological data ? Causal role of sunscreen chemicals ? False sense of security in those at risk – spend longer out doors but don’t reapply appropriately


AIDS IN CLINICAL DIAGNOSIS: AIDS IN CLINICAL DIAGNOSIS GLASGOW SYSTEM Major: Change in size Irregular pigment Irregular outline Minor: Diameter >6mm Inflammation Oozing/bleeding Itch/altered sensation AMERICAN ‘ABCDE’ SYSTEM Asymmetry Border Colour Diameter Examination


TYPES OF MELANOMA: TYPES OF MELANOMA


NODULAR: NODULAR Commoner in males Trunk is a common site Usually thick with a poor prognosis Black/brown nodule Ulceration and bleeding are common


SUPERFICIAL SPREADING: SUPERFICIAL SPREADING The most common type of MM in the white-skinned population – 70% of cases Commonest sites – lower leg in females and back in males In early stages may be small, then growth becomes irregular


ACRAL LENTIGINOUS MELANOMA: ACRAL LENTIGINOUS MELANOMA In white-skinned population this accounts for 10% of MMs, but is the commonest MM in nonwhite-skinned nations Usually comprises a flat lentiginous area with an invasive nodular component


SUBUNGAL MELANOMA: SUBUNGAL MELANOMA Rare Often diagnosed late – confusion with benign subungal naevus, paronychial infections, trauma Hutchinson’s sign – spillage of pigment onto the surrounding nailfold


LENTIGO MALIGNA MELANOMA: LENTIGO MALIGNA MELANOMA Occurs as a late development in a lentigo maligna Mainly on the face in elderly patients May be many years before an invasive nodule develops


AMELANOTIC MELANOMA: AMELANOTIC MELANOMA Diagnosis is often missed clinically The lack of pigmentation is due to the rapid growth of the tumour and the differentiation of the malignant melanocytes


METASTATIC MELANOMA: METASTATIC MELANOMA


PROGNOSTIC VARIABLES: PROGNOSTIC VARIABLES The Breslow thickness is the single most important prognostic variable (distance in mm of the furthest tumour cell from the basal layer of the epidermis)


Slide19: Scalp lesions worse prognosis, then palms and soles, then trunk, then extremeties Younger women appear to do better than either men at any stage or women over 50 Ulceration of the tumour surface is a high risk factor


MANAGEMENT: MANAGEMENT Surgical excision – 1-3cm margins depending on breslow depth Invasive primary MM on the digits can be treated by amputation Need to investigate all MMs over 1mm for metastases – CXR, USS abd or CT chest, abd, pelvis, bloods – FBP, LFTs, LDH New scanning modality in Belfast – PET scan – for high risk primaries or evaluating lymphadenopathy


FOLLOW UP: FOLLOW UP No general agreement on time period Depends on tumour thickness Thick tumours – 5-10 years Need to examine the scar and check for lymphadenopathy, liver, spleen, and total body examination for other suspicious naevi


PLANTAR MALIGNANT MELANOMA: PLANTAR MALIGNANT MELANOMA Caucasians – 1-9% Asians – 29-46% Afro-Carribean – 60-70%


SUBUNGAL MELANOMA: SUBUNGAL MELANOMA TRAUMA


Dwyer PK et al British Journal of Dermatology 1993;128:115-120: Dwyer PK et al British Journal of Dermatology 1993;128:115-120 51 white caucasian patients west of Scotland with plantar melanoma 20 – sup spreading melanoma 27 – acral lentiginous 4 – nodular Female:male – 3:2


Franke W et al Melanoma Research 2000;10:571-576: Franke W et al Melanoma Research 2000;10:571-576 Prognosis for plantar melanoma poor Poor survival can be improved by a significant reduction in the time period between the first observation of a plantar skin lesion and surgical treatment


Walsh SM et al The Journal of Foot and Ankle Surgery 2003;42(4):193-198: Walsh SM et al The Journal of Foot and Ankle Surgery 2003;42(4):193-198 “…..that the clinician must maintain a high index of suspicion when a patient presents with a pigmented or atypical lesion on the foot.”