Flashcards in Disorders of Pigmentation and Melanocytes Deck (25):
What cells are responsible for skin pigmentation?
Where are melanocytes located within the skin?
Embryologically, where are melanocytes derived from?
Neural crest cells
Where is melanin synthesized within the melanocyte?
What precursor molecule is used to synthesize melanin?
A patient presents with a localized loss of skin pigmentation. It was found that an autoimmune destruction of the patient’s melanocytes was occurring. What is the mostly likely diagnosis for this patient?
What enzyme defect is seen with albinism?
Trosinase—impairing melanin production
What are the 2 forms of albinism?
Ocular form—involving just the eyes
Oculocutaneous form—involving the skin and the eyes
Patients who have albinism are at an increased risk of developing what 3 cancers?
Squamous cell carcinoma
Basal cell carcinoma
What causes the darkening of then skin, causing a freckle?
Increased number of melanosomes
Melanocytes are NOT increased
A mask-like hyperpigmentation of the cheeks that has an association to pregnancy and oral contraceptives?
A benign neoplasm of melanocytes?
A nevus that is present at birth and is often associated with hair growth?
What is the most common nevus (mole) in children?
What is the most common nevus (mole) in adults?
What are the characteristics of a nevus?
Flat macule or raised papule that is symmetric, with sharp boarders, even distribution of color, and
What type of nevus is a precursor to melanoma?
A malignant neoplasm of melanocytes that is the most common cause of death from a skin cancer?
What are the 4 major risk factors for the development of melanoma?
Prolonged exposure to sunlight
Dysplastic nevus syndrome
What is the presentation of melanoma?
Diameter > 6mm
What are the two growth phases of melanoma?
What is radial growth of melanoma and its risk of metastasis?
Horizontal growth along the epidermis and superficial dermis
Low risk of metastasis
What is vertical growth of melanoma and its risk of metastasis?
Growth that occurs deep into the dermis of the skin
What are the 4 variants of melanoma?
Lentigo maligna melanoma-radial growth
Nodular-early vertical growth