Dermatopathology Flashcards
What is the difference between a macule and a patch?
A macule is a flat small region of skin with a different color or texture. (like freckles)
A Patch is actually just a macule bigger than 1cm
What is a papule?
A palpable change in consistency or contour of the skin
What do you call a large papule? (diameter greater than 1cm)
a nodule
What do you call a large nodule?
a tumor!
What do you call a coalescence of papules?
a plaque
What is a cyst?
An encapsulated nodule filled with soft material!
A little bump underneath the skin
example: epidermal cyst
What is the difference between vitiligo and albinism?
Albinism - body has defective tyrosinase enzyme, you have normal melanocytes, but they can’t make any pigment
Vitiligo - autoimmune destruction of melanocytes, lymphocyte mediated, have normal enzyme
What is malasma?
Hyperpigmentation often caused by pregnancy or medications
(resolves afterward)
mask-like face hyperpigmentation
worsened by sunlight
What pigmentation lesions are caused by excess melanin, and which are caused by too many malnocytes?
Due to excess melanin
- Freckle
- Melasma
- Solar lentigo
Increased number of melanocytes
- Melanocyte hyperplasia (Lentigo simplex)
- Melanocytic neoplasia (Nevi, Melanoma)
Explain : Solar lentigo
Hyperpigmentation due to excess melanin exposure
Caused by sun exposure - a protective mechanism of melanocytes
What is lentigo simplex?
Localized hyperplasia of melanocytes (increased number of cells)
NOT sun-related
small brown macules
What is cancer? Why shouldn’t you use this term with other physicians?
A malignant neoplasm!
It isn’t really specific…
What are benign vs malignant melanocytic neoplasms called?
Benign: Nevi (basically just moles)
Malignant: Melanoma
Nevi start growing where? Where do they grow later?
They start in the epidermis and later move into the dermis and grow there.
What’s important to know about a spitz nevus?
Big red papule
Cut out that whole thing! Some can behave in crazy ways! So ya, just remember that
What are dysplastic nevi and why are they clinically important?
Basically just nevi with odd borders, shapes and colors
Multiple dysplastic nevi is a marker of increased risk of melanoma
What are the ABCD’s of melanoma?
Asymetry
Border
Color
Diameter
Best predictor of melanoma metastasis is what?
Less than 1mm of deep has better prgnosis 95% survival. The further deep they are the worse prgnosis!
More than 4mm deep, 37-50% survival
Referred to as “Breslow’s Depth”
What is the sentinel lymph node?
The closest lymph node to the biopsied melanoma. Found using injected dye.
What is a Seborrheic Keratosis?
Epithelial neoplasm - brown velvety papules or plaques
Benign!
What are skin tags?
Just an overgrowth of normal skin, looks like small flesh-colored bag
What is actinic Keratosis
Benign neoplasm, rough scaly spots on sun-exposed skin
Have very small chance of becoming squamous cell carcinoma - treat with liquid nitrogen
Squamous cell carcinoma becomes malignant when:
It invades through the basement membrane of the dermis
Describe Cowden’s syndrome:
Got a feeling this is on the test…
Hereditary condition - mutation in PTEN (tumor supressor gene)
Patients prone to multiple harmartomas as well as many malignant neoplasms
Skin has trichilemmomas, brain lesions
Cobblestoning tongue
Describe Muir-Torre Syndome:
Also VERY testable…
Hereditary mutation in MLH1, MSH2 (DNA mismatch repair proteins)
More prone to many carcinomas
Why would it be important to do a punch biposy rather than a shave biposy for a melanoma?
It will allow you to see how deep it goes to establish how serious it is.
