What is Vulvar Melanosis?
Vulvar Melanosis is a benign condition presenting as darkly pigmented irregular macules on the vulva clinically suggesting malignant melanoma. The melanotic macules show lower epidermal pigmentation without melanocytic atypia or nesting. It is a harmless condition that may not require any treatment [1].
What are the Causes of Vulvar Melanosis?
Although a definitive cause for Vulvar Melanosis is not clear, unlike cutaneous melanomas, ultraviolet radiation does not appear to be a contributor as the vulva is absent from sun-exposed areas [2]. Other studies have proposed potential triggers such as chronic inflammatory disease, viral infections and irritant agents as potential triggers in mucosal melanoma which could hypothetically apply to Vulvar Melanosis [3]. However, further research would be imperative in verifying potential causes and confirming such an assertion for Vulvar Melanosis.
What is Melanoma?
Melanoma is a type of skin cancer found in cells called melanocytes, the cells that produce the pigment melanin which gives skin, hair and eyes their colour. Melanoma is the most dangerous and potentially deadly form of skin cancer because it can spread to other parts of the body. If Melanoma is detected and removed when it is still localized, the cure rate is high. But if Melanoma has spread, the chance of a cure is significantly lower. Melanoma can originate on any part of the body, although it is most often located on the chest and back in men, and on the legs in women. Melanoma can develop on the face or the neck too. Much less commonly, Melanoma can develop in the eyes or in the intestines or other internal organs [4, 5].
What are the causes of Melanoma?
There is no single cause for melanoma but it is generally believed to result from a combination of environmental risk factors and genetic factors. The obvious environmental factor is sun exposure and other sources of ultraviolet radiation (UVR) such as sunbeds. Damage to the DNA of skin cells can also cause cancer, and prolonged UVR exposure is thought to play a major role in the causation of Melanoma. From a purely health perspective, anyone with an allergic or sensitive reaction to sun exposure, anyone who freckles or burns easily, and anyone with a light skin tone and otherwise low levels of melanin are particularly at risk [6, 7, 8].
Importantly, genetic predisposition is also an important factor in whether or not someone develops Melanoma. Around 10 per cent of people who develop Melanoma have a family history of the disease. Having a very large number of moles on the body, as well as having a compromised immune system, are also significant risk factors for Melanoma [9].
Although UVB radiation does directly damage DNA, UVA radiation does so indirectly by a process of generating reactive oxygen species. But precisely how damaged DNA from skin cells leads to the development of Melanoma remains unclear [10, 11].
Vulvar Melanosis vs Melanoma
Vulvar Melanosis and Melanoma, while both involving pigmentation changes, have distinct characteristics and implications.
Vulvar Melanosis is a common pigmentary change that accounts for most pigmented vulvar lesions. It presents as single or multiple asymptomatic macules or patches of varying size and colour that may be asymmetric with poorly defined borders. The most frequent location for Vulvar Melanosis is the labia minora (43%), followed by the labia majora (26%) [12]. Despite changes in size and colour over time, Vulvar Melanosis is generally a benign entity and does not signify malignant transformation [12].
On the other hand, Melanoma is a type of cancer that grows out of the melanocytes – the pigment-producing skin cells that impart a variety of complexion-altering colours [13]. Melanoma cancer cells are more aggressive than most kinds of skin cancer and about 75% of skin cancer-related deaths are caused by this dastardly disease. Often, Melanoma is associated with a dark mole on the skin: but the cancerous cells may also grow out of other tissues such as the eye, the mouth, fingernails or toenails [13].
Melanoma is a cancer of the neural crest-derived ectodermal cells involved in the pigmentation of skin and other tissues [14]. It is also medically called malignant melanoma or cutaneous melanoma [15]. The incidence of Melanoma has been increasing over the years and cancer is becoming an emerging public health issue globally [13, 15].
Conclusion
In conclusion, while both Vulvar Melanosis and Melanoma involve changes in pigmentation, they differ significantly in terms of their prevalence and severity.