Give at least 5 disorders with definition, etiology, epidemiology, risk factors, pathophysiology
and treatment.
Melanoma
Definition: Melanomas are cancers that are distinguished by the unchecked proliferation of
melanocytes, the epidermis' pigment-producing cells. Typically, a mole serves as the origin of a
melanoma. Being the most aggressive and difficult to diagnose before it has spread to other organs, it
is the most lethal of all skin cancers.
Etiology: Melanomas are produced by melanocytes, which develop from the neural crest and travel
to the epidermis, uvea, meninges, and epidermis. At the intersection of the dermis and epidermis, the
basal layer of the epidermis contains the melanocytes, which live in the skin and create a shielding
melanin. Melanomas can form in or close to a precursor lesion that has already existed, as well as in
skin that appears to be healthy. Without any sign of a precursor lesion, a malignant melanoma
forming in healthy skin. These melanomas are frequently brought on by exposure to sunlight. The
palms, feet, and perineum are examples of non-exposed skin regions where melanoma can develop.
Epidemiology: Over the past 50 years, there has been a sharp rise in the frequency of melanoma
around the world, with individuals with fair skin and those closest to the equator experiencing the
disease most frequently. The highest age-standardized incidence of melanoma in the world, with 32.5
incidences per 100,000 people, is found in Australia and New Zealand. Whites are more likely than
Blacks and Asians to develop melanoma. Black people are thought to get melanoma at a rate one
twentieth that of White people. Additionally, compared to persons with light complexion, white people
with dark skin have a significantly lower risk of having melanoma. The typical melanoma sufferer has
pale skin and tends to burn in the sun rather than tan. It seems that white persons with blond or red
hair and plenty of freckles are most likely to develop melanomas. Whites have the highest incidence,
with 20–30 occurrences per 100,000 people per year in Hawaii and the southwest of the country.
Risk factors:
fair skin. Less melanin (the skin's pigment) means less defense against harmful UV rays. a
background of sunburns. Your risk of developing melanoma is impacted by one or more
painful, blistering sunburns.
living at a better elevation or closer to the equator. UV radiation exposure is higher for people
who live nearer to the equator, where the sun's rays are more direct, than for those that live
farther north or south.
having uncommon or numerous moles. Having quite 50 common moles on your body raises
your risk of developing melanoma. Additionally, the danger of melanoma is increased by
having a novel sort of mole.
Pathophysiology: Melanomas can form in or close to a precursor lesion that has already existed, as
well as in skin that appears to be healthy. Without any sign of a precursor lesion, a malignant
melanoma forming in healthy skin is said to emerge de novo. The cause of many of these melanomas
is solar exposure. The palms, soles, and perineum are examples of non-exposed skin regions where
melanoma can develop. Radial and vertical growth phases are present in melanomas. Malignant cells
proliferate radially in the epidermis during the radial growth phase. The majority of melanomas
eventually reach the vertical growth phase, where the cancerous cells infiltrate the dermis and
acquire the capacity to spread.
Treatment:
Wide local excision of primary melanoma down to deep fascia is performed during surgical
excision (first line treatment). The lesion's thickness determines the resection margins.
Regional lymph node removal: the choice to undertake full lymph node dissection depends on
the likelihood of recurrence and the findings of sentinel lymph node biopsy.
Chemotherapy: Cytotoxic chemotherapeutic drugs used to treat metastatic melanoma include
dacarbazine, temozolomide, and fotmustine. Low response rates and no improvement in
overall survival are observed in patients. Patients who cannot receive immunotherapy or
monoclonal antibody therapy are the only ones who can receive this treatment.
Radiation therapy: utilized as a palliative measure, as a primary treatment for mucosal lesions,
or as an adjunct to surgical excision.
