Melanoma in Situ: Prognosis, Recurrence, Margins, Treatments

The global population is so clued up nowadays on the dangers of excessive exposure to harmful rays of sunshine. Additionally, the environmental lobby has fuelled this with tons of information broadcast in the public domain about the hole in the ozone layer. So, forget tanning parlours and sun beds, so last century, it’s all about covering up with Factor 50 or fake spray tans to achieve that golden glow and honeyed look. Melanoma is a diagnosis most people associate with the skin but what is the actual meaning of melanoma?

Spotting melanoma

Melanoma originates in the skin cells and is therefore frequently visible unlike other forms of cancer which remain invasive and hidden. Melanoma derives its name from melanin, a darkish brown or black pigment present in the skin, hair and eyes in both people and mammals. Melanin controls the skin’s tanning response via Melanocytes, the skin’s pigment cells.

To create melanoma, there is usually an external trigger, for instance, commonly persistent sunburn or just continuous quantities of UV light. Ethnically, Caucasian people are at greater risk than those with darker skin tones such as people of African or Hispanic heritage.

What is the most likely prognosis of melanoma in situ?

Melanoma originates in the skin cells and is therefore frequently visible unlike other forms of cancer which remain invasive and hidden. Melanoma derives its name from melanin, a darkish brown or black pigment present in the skin, hair and eyes in both people and mammals. Melanin controls the skin’s tanning response via Melanocytes, the skin’s pigment cells. To create melanoma, there is usually an external trigger, for instance, commonly persistent sunburn or just continuous quantities of UV light. Ethnically, Caucasian people are at greater risk than those with darker skin tones such as people of African or Hispanic heritage.

What is the most likely prognosis of melanoma in situ?

Melanoma is a form of cancer which causes death if it spreads or metastasizes to other locations in the body including internal organs. A melanoma discovered in situ, therefore, is routinely awarded the prognosis of malignancy requiring prompt intervention. Malignant melanoma in situ is clinically defined as a thin but spreading patch of melanoma the depth of which is relative to the gravity of the disease. It may be no deeper than the superficial skin layers but characterised by outward spread and increasing in diameter.

How is melanoma detected?

Melanomas are visible so cancer which is potentially identified early. Melanoma may not necessarily evidence as a new growth or change in fresh unblemished skin, it can manifest as an alteration to the appearance of an existing mole or birthmark. Glance at these pictures to familiarise yourself with the identity of melanoma.

Different types of melanoma

A melanoma diagnosis tends to fall into one of three categories, Spreading melanoma, Nodular melanoma which centres around a mole or other normally harmless skin condition and Lentigo melanoma which involves freckles.

Are there sites on the body where melanoma is more common?

Melanomas as a generalisation occur on the legs of females and on the backs of males, possibly reflecting popular fashion and clothing trends in hot weather, exceptions always prove the rule, however.

Melanomas can develop on the face, usually presenting as a slowly growing odd-shaped freckle. Rarely, there are instances of subungual melanoma sited under the fingernails and acral lentiginous melanoma are on the palms of the hands and soles of the feet.

What is the treatment for melanoma in situ?

Treatment options involve surgical excision which aims to remove cancerous tissue plus a small quantity of healthy skin to ensure that nothing has been overlooked. Adequate clearance is confirmed by histology whereby excised skin is studied in a laboratory environment under a microscope. This is the standard treatment regimen for melanoma in situ plus close monitoring and follow-ups of the patient to detect any progression of the disease. Melanoma which has metastasized thereby affecting other parts of the body requires more aggressive treatments such as chemotherapy or radiotherapy.

What are the average margins removed with melanoma in situ?

Currently, surgeons will harvest approximately 5mm of unaffected skin around the lesion. This became a documented industry standard in 1992. Evidence is increasingly demonstrating that this amount is conservative but no scientific data exists to suggest a more appropriate alternative.

Despite cutting edge technology – pun intended! – so bright lighting, something called Woods lighting which is black light invisible to the naked eye and, the enhancement of magnification – the clinician cannot take the risk that he has missed a tiny portion of cancerous cells, undetectable with the naked eye. Thus, the debate over accurate and beneficial margins in cases of melanoma in situ continues to rage amongst the medical profession. Most sufferers want the minimal loss of skin for cosmetic reasons but fear the return of cancer more.

What are the stages of melanoma?

Very rapid skin changes are often far less concerning than those materialising over the passage of time. Actual confirmation of melanoma is undertaken via biopsy. A tiny segment is removed for specialist analysis. A positive corroboration is accompanied by a benchmark of severity simply referred to as Stages I-IV, the latter being the most serious. Stage labelling allows the doctor to understand the progression of the disease and determine the most efficacious interventions. The first three stages refer to the depth of melanoma within the skin, size and possible ulceration. Only Stage IV indicates that the illness has spread to other organs.

What is the recurrence of melanoma in situ following surgery?

Survival rates hinge almost totally on the original status of the melanoma at point of diagnosis. Prompt identification and treatment are therefore crucial to happy outcomes. Further primary i.e. not secondary developments, melanomas in situ have a recurrence rate of 0.5% per annum for the first five years post-treatment, decreasing thereafter. Certain age ranges demonstrate a greater propensity for recurrence too, those aged between 15 and 39 and 65 to 79 with the middle years less favoured.

 

 

Article References:

  1. https://blog.dana-farber.org/insight/2014/07/what-are-the-most-common-sites-for-melanoma/
  2. https://www.medicinenet.com/melanoma/article.htm#what_are_the_types_of_melanoma
  3. https://journals.lww.com/dermatologicsurgery/Abstract/2016/03000/Excision_Margins_for_Melanoma_In_Situ_on_the_Head.7.aspx
  4. https://www.dermnetnz.org/topics/wood-lamp-skin-examination/
  5. https://www.jwatch.org/jd201204060000001/2012/04/06/surgical-margins-melanoma-situ
  6. https://www.aimatmelanoma.org/stages-of-melanoma/

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