ALL photos in this note are from DermNet NZ – https://www.dermnetnz.org/topics/melanoma/
Visit the above link to see all photos 
 
Melanoma is more associated with episodic intense sunburns than more continuous sun exposure.
Melanomas are malignant tumours derived from melanocytes, usually on the skin. Occasionally a primary melanoma develops in other organs that have melanocytes (eg eyes, genitals, buccal mucosa, bowel). The most common site for melanoma is the leg in women and the back in men (ie not the body parts most exposed to the sun).
 
 The main risk factors are: ( important for KFP ) 
    • elderly male 
    • blistering sunburns as a child or adolescent
    • fair complexion, blue eys rather than brown, and red/blond hair  –  and a tendency to sunburn ( rather than tan ) 
    • marked solar skin damage ( episodes of intense sun exposure ) 
    • multiple common melanocytic naevi
    • dysplastic naevus syndrome
    • PHMX – history of previous melanoma or nonmelanoma skin cancer
    • Drug Hx and PMHx – immunodeficiency.
    • Family Hx – family history of melanoma
 
History –
The most important feature of the history is to ask about is whether there has been any change in the skin lesion.
For melanoma, changes most often occur over months. 
The early changes are those in size, shape and colour. As the melanoma invades, it may become raised, which can be associated with bleeding or crusting.( Commonest symptom of invasion is itchiness ). Although most of these changes are not associated with symptoms, the most common sensation is itching. 
Consider melanoma when a lesion is:
    • new or changing (most melanomas arise de novo rather than from a pre-existing mole)
    • prominent and pigmented and stands out from other moles (‘ugly duckling’)
    • a rapidly growing nodule of any colour
    • of particular concern to the patient
    • typical dermatoscopically (eg asymmetric pigmentation, blue-white veil, multiple brown dots, pseudopods, radial streaming)
    • changed on subsequent dermatoscopy.
A mnemonic for the appearance of melanomas is the ABCD[E] rule:
    • Asymmetry – one half different from the other 
    • Border irregularity 
    • Colour variation -varies within the lesion. Pigment is largely or completely absent in hypomelanotic melanoma
    • Diameter – greater than 6 mm. Sometimes melanomas are diagnosed when smaller than this—an increasing diameter is more important than size
    • Evolution –  changing or evolving
    • “ugly duckling” sign can help identify melanoma.
1) Superficial spreading melanoma is the most common type, usually presenting as an irregularly pigmented macule or plaque. 
Through a dermatoscope this melanoma is typically a range of colours, with architectural disorder, radial streaming, branched streaks, pseudopods, peripheral black dots and blue-white structures.
 
2) Nodular Melanoma is aggressive and invasive, and can grow rapidly over weeks and ulcerate. 
The colour varies from black through red. 
Approximately 50% are hypomelanotic. 
Often a nodular melanoma defies the ABCDE rule, and the mnemonic EFG (ie ‘elevated, firm, growing’) is more appropriate. 
E- Elevated 
F- Firm 
G- Growing 
Rarely, a nodular melanoma is pedunculated and can resemble a pyogenic granuloma or basal cell carcinoma. Dermatoscopy is less useful for a thick nodular melanoma.
 
3) Acral lentiginous melanoma is the most common type in people with dark skin. It presents on the palms, soles or nail bed. Tumours are often large as they are diagnosed at a late stage.
 
 
4) Lentigo maligna typically occurs on severely sun-damaged skin. Mainly it affects older patients, but occasionally it occurs in adults younger than 40 years. Lentigo maligna is an in situ melanoma, and the delay before it invades is often long and unpredictable. Patients are often aware of an irregular, brown-to-black facial macule for many years. Therefore, lentigo maligna can be quite large at presentation, even though it is still restricted to the epidermis. Histology is needed to distinguish it from other pigmented facial lesions and to detect invasive melanoma (lentigo maligna melanoma). Dermatoscopically, lentigo maligna may have an annular–granular pattern, asymmetric pigmented follicular openings and rhomboidal structures. Invasive melanoma can develop unpredictably, so active treatment of lentigo maligna is advised.
 
D/D for Lentigo maligna 
    • solar lentigo 
    • flat seborrheic keratosis
    • Pigmented acnetic keratosis / solar keratosis 
 
5) Desmoplastic melanoma is rare and aggressive. Its appearance is often subtle, and sometimes scar-like. 
Most are nonpigmented. Desmoplastic melanoma may be associated with overlying lentigo maligna.
A small but significant number of melanomas cannot be diagnosed clinically, and a history of lesion change can be the only clue.
 
Amelanotic and hypomelanotic melanoma ( AHM ) 
 
Amelanotic melanoma – 
 
Examination – 
The most important aspect of clinical examination is to examine the whole skin surface – under good lighting. In particular, if melanoma is suspected, the patient should be examined for enlarged lymph nodes in the appropriate draining area (eg axilla or groins). 
The accuracy of a melanoma diagnosis has been found to be increased by those in general practice with a sub-specialty and training in dermoscopy. 
Others are encouraged to refer.
 
Management – 
Even When a confident clinical diagnosis of melanoma is made – excision biopsy with a 2 mm margin along with a cuff of subdermal fat,  is needed to be done with the orientation to the excision margins  – (NHMRC guideline) 
( Cancer council states ( 2020 ) – The optimal biopsy approach for a suspicious pigmented lesion is complete excision with a 2 mm clinical margin and upper subcutis. Subcutis is the subcutaneous fat. Hence its the same as NHMRC advice).
An excisional biopsy should be performed with consideration of definitive surgery in mind, should the diagnosis of melanoma be confirmed. As such, the incision should be oriented along Langer’s lines of stress on the trunk and parallel to the long axis of the extremity for extremity lesions. Such an incision facilitates the subsequent closure of a wide local excision and reduces the need for skin grafting.
Most excisions should be performed with elliptical incisions, with the required margin included in the short axis of the ellipse
For large lesions, a punch or incisional biopsy permits the diagnosis of melanoma to be made in most cases. However, an incisional biopsy may not accurately assess tumor thickness if the thickest portion of the lesion is not sampled
 
Must never do wide local excision in the first go. 
the reason is that if you do a wide local excision – 
   1) it may lead to excessive or inadequate tumour clearance 
   2) it will be impossible to map the draining lymph nods there after. ( sentinal nodes mapping) 
 
Partial biopsies such as punch biopsies, incision biopsies and shave biopsies are frequently unsatisfactory and may result in misdiagnosis due to unrepresentative sampling. 
 

Definitive treatment by wide excision

The width of excision required for a particular melanoma is based primarily on its Breslow thickness 
 
The arrow indicates the Breslow thickness. This is defined as the microscopically measured vertical depth of invasion of the tumour from the granular layer of the epidermis to its deepest part within the dermis or subcutaneous tissue
Melanoma has the potential to metastasize to any organ; common sites of dissemination include the skin, subcutaneous tissues, lymph nodes, lung, liver, bone, brain, and visceral organs.
The likelihood of the melanoma having spread is directly related to prognostic factors, particularly depth of invasion.
 
The histology report would give us the breslow thickness – 
This would decide the next step in management 
 
Breslow thickness*
Surgical margin
Melanoma in situ
0.5cm ( 5 mm) margin – repeat excission shuld be done 
Wider margins (>5 mm) may be required for in situ lentigo maligna melanoma based upon final pathologic evaluation
Melanoma <1.0 mm
1 cm – repeat excision should be done ( provided its not stage 3 or above based on clinical staging) 
melanomas <1.0 mm thick but with ulceration, – Sentinel node biopsy should be considered before wide  local excision
Melanoma 1.0–4.0 mm
1–2 cm is the excision to be organised  –
However, a referral to a specialist is recommended at this level of thickness – 
sentinel node biopsy should be performed before wider local excision through a specialist centre. (Sentinel node biopsy can not be done after wide local excision)  
Melanoma >4.0 mm
2 cm  – same as above – 
* For melanomas 2–4 mm thick, it may be desirable to take a 2 cm margin where possible
 
Same table – from a check – 
 
Acral lentiginous and subungual melanoma are usually treated with a minimum margin as set out above, where practicable, including partial digital amputation usually incorporating the joint immediately proximal to the melanoma
 
If melanoma is confirmed, and some of the lesion was left behind after the initial excision, wide local excision should be performed as soon as possible. Ideally, if all the lesion was removed in the initial excision, wide local excision should be performed within 4 weeks.
 
Depth of excision in usual clinical practice is excision down to but not including the deep fascia unless it is involved. The excision depth should be the same as the lateral margin when possible, but no further than the deep fascia.
 
KNOW THIS part typed in pink – ( know the concept only ) –
A sentinel node is one that receives lymphatic drainage directly from the primary tumour site. Lymphatic mapping to determine the location of sentinel nodes involves the intradermal injection of a small dose of radioactive tracer at the primary tumour site. At the time of surgery, the surgeon injects patent blue dye adjacent to the primary tumour and identifies the sentinel node as ‘hot and blue’ through a small incision at the location indicated by the radiologist. The sentinel node is removed and sent for histological examination. Often there may be sentinel nodes in more than one lymph node field, particularly if the tumour is located along the central axis of the torso. Melanomas of the head and neck region regularly drain to more than one zone of the cervical node field.
Patients who are being considered for sentinel node biopsy should be referred before wide local excision of the primary tumour site. If sentinel node biopsy is being considered it is important that lymphatic mapping be done prior to wide excision.
Patients who have positive sentinel lymph node biopsy be offered completion lymphadenectomy, or be referred to a specialist centre for discussion of further treatment options
metastases are rare for thin melanomas (< 0.75mm) and the risk for tumours 0.75–1.0mm thick is about 5%. Intermediate thickness melanomas (1–4mm) have a risk that starts at about 8% for 1mm tumours and this rises steadily to 30% with increasing depth. Melanomas thicker than 4.0mm have a risk of approximately 40% for nodal involvement, in addition to a high risk of systemic spread, but the involved regional nodes are usually not clinically apparent at the time of primary diagnosis
 
Extracts from Check – 
 
Based on Breslow thickness, LN spread and distant metastasis, melanoma are staged in to 5 stages 
    • Stage 0: <0.1 mm  – melanoma is in the top layer of skin – epidermis – ( insitu ) 
    • Stage 1: <2 mm without ulceration or up to 1 mm with ulceration
    • Stage 2: >2 mm or > 1mm with ulceration 
    • Stage 3: spread to lymph nodes
    • Stage 4: distant spread.
Serum lactate dehydrogenase (LDH) should be obtained in all patients as it has prognostic significance for patients with stage IV disease and could be used as a biomarker for response to treatment
 
KNOW THIS – ( know the concept only ) –
 
People with a large number of pigmented naevi on their skin are more likely to develop melanoma.
The risk of developing melanoma is increased 10-fold in a patient with a past history of melanoma, and 4-fold in a patient with non-melanoma skin cancer. 
Having a first-degree relative (ie parent, child or sibling) doubles the risk of a person developing melanoma.
 
FOLLOWUP – 
 
A guide for a patient who has had melanoma is to see their doctor for a full skin and lymph node check 
 
( based on uptodate ) 
every 3 months for 2 years, then every 6 months for 2 years, then every year after that.
 
 
(Check – 2015 states  ) –
for stage 1 disease – 6 monthly for 5 years and yearly there after 
                                – stage 2 and 3 – followed up every 3 months – 
 
 
( uptodate states ) 
Patients determined to be at high risk of developing melanoma, based on the presence of multiple atypical nevi, history suggesting a familial melanoma syndrome, or patients with “red hair phenotype,” should be educated regarding the need for regular full skin examinations by clinicians with skin expertise, skin self-examination, and sun protection. 
 
Autosomal dominantly inherited mutations in melanoma susceptibility genes are responsible for only a small proportion of cutaneous melanomas and the role of genetic screening should be limited to patients participating in a defined research program. (See ‘High-risk individuals’ above and ‘Genetic screening’ above.)
 
the Australian and New Zealand Guidelines recommend only history and physical examination with imaging studies prompted by clinical complaints while the Swiss Guidelines recommend positron emission tomography (PET)/computed tomography (CT) scan every 6 to 12 months for stages IIC and III patients.
 
In conclusion, historically the major value of the follow-up visits was to detect potentially surgically curable recurrences, particularly locoregional. With the advent of more effective systemic therapies, this paradigm is clearly evolving. At a minimum, we recommend a detailed medical history and physical examination with special attention to regional recurrences every 3 to 12 months, depending on the risk of recurrence. 
 
Followup in general population – ( uptodate) 
 
●We suggest that persons at high risk for melanoma (white men ≥50 years, individuals with a history of significant sunburn or multiple moles, and individuals with “red hair phenotype”) have a periodic full-body skin examination performed by a clinician who has had appropriate training in the identification of melanoma.
 
●We recommend that individuals at especially high risk (history suggesting a familial melanoma syndrome or with multiple atypical nevi) have a regular full-body skin examination by a clinician with skin expertise. The optimal frequency for such examination is unknown.
 
●We do not suggest routine screening for the general population outside of these risk groups. However, for patients without identified increased risk, clinicians should remain vigilant for any suspicious lesions identified in the course of a routine or sick visit (opportunistic case finding) and make appropriate referrals for further evaluation of all such lesions.
 
 
EFG
elevated, firm and growth – melanoma until otherwise
 
RRR
red, raised and recent change – melanoma
 
Subungal Melanoma – under the nail 
 
Longitudinal melanonoychia is not malignant
 
 
This is not melanoma – this needs just reassuarance 
subungal haematomas 
 
 
 
 
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