Week 1 - Disorders of Cutaneous Pigmentation & Cutaneous Neoplasms

Question 1

Neoplasms usually arise from. . .

Answer 1

the epidermis & the dermis

Question 2

Dermis

Answer 2

Consists of collage/elastic fibers, peripheral nerves, muscle, fat, cartilage

Question 3

Vitiligo

Answer 3

Partial or complete loss of melanocytes, well demaracated macules/patches, hand/wrist, axillae, perioral/periorbital, anogenital
Pathogenesis: autoimmune - T cells attack melanocytes of skin & destroy them - then you get hypopigmented cells

Question 4

Neoplasia

Answer 4

Proliferation of genetically abnormal cells - clonal population or proliferation of cells that can escape the normal cell checkpoints

Question 5

Cancer

Answer 5

Malignant Neoplasm

Question 6

Benign vs. Malignant

Answer 6

Benign = can't metastasis
Malignant = has potential (does not have to) metastasize

Question 7

Albinism

Answer 7

No melanin produced (or decreased melanin)
Inherited defect in tyrosinase!! (normal number of melanocytes)

-Congenital absence of enzyme and melanin is not made or is decreased

Question 8

Stromal Neoplasms

Answer 8

Neoplasms involving connective tissue

Question 9

Nevus (mole)

Answer 9

Benign neoplasms of melanocytes, congenital or acquired - most have mutations (BRAF most common)

Question 10

How do we predict the probability of melanoma to metastasize?

Answer 10

Depth of invasion

Question 11

What is Breslow’s depth?

Answer 11

It is the probability to metastasize that is predicted by depth of invasion of the melanoma

• Measured in millimeters
• Best indicator of probability to metastasize

Question 12

Breslow’s depth

Answer 12

How deep melanoma invades into the dermis (measure from the granular layer to the lowest melanocyte)
-Best prognostic indicator!!

Question 13

Sentinel lymph node biopsy:

Answer 13

Usually for melanomas > 1 mm in thickness - melanomas like to go to lymph nodes (they usually go here first - so if melanoma isn’t here, it usually hasn’t metastasized)

Question 14

Breslow depth & Survival:

Answer 14

4 mm: 5 yr sur. is 37-50%

Question 15

Next most imp. prognostic indicator (after Breslow depth for melanoma):

Answer 15

Ulceration (usually growing very fast), mitotic rate of cells

Question 16

Squamous cell carcinomas

Answer 16

Almost all are sun-related (sometimes related to radiation)

Question 17

Basal cell carcinoma

Answer 17

Most common human malignancy - rarely metastasizes - risk factors include sun exposure, XP, light pigment - can be ulcerated, large papules on the nose

Question 18

Cowden’s syndrome & Muir Torre Syndrome - common symptom:

Answer 18

Adnexal neoplasms/proliferations: differentiate toward hair follicle/glands, benign and malignant types

Question 19

Cowden’s Syndrome:

Answer 19

Hereditary condition prone to multiple hamartomas and malignancy
Skin: multiple trichilemmomas (face- benign proliferation of hair follicle epithelium), benign keratoses on acral skin
-Mucosal papules, cobblestoning tongue
-Internal: breast, endometrial and thyroid carcinoma
-Cerebellar lesions
-Mutation in PTEN (tumor suppressor gene) <– KNOW!

Question 20

Adenoma

Answer 20

Benign tumor of epithelial tissue

Question 21

carcinoma

Answer 21

Malignant tumor of epithelial tissue

Question 22

Multi-Torre Syndrome:

Answer 22

• Hereditary syndrome: germline mutations in DNA mismatch repair proteins: MLH1, MSH2, MSH6, PMS2
• These repair errors in base pairing during replication, especially in 1-2 bp repeats (microsatellites)
• Skin: sebaceous adenoma and carcinoma, keratoacanthomas
• Internal carcinomas: Colon/rectal, endometrial, ovarian
• Represents subset of hereditary non-polyposis colorectal carcinoma syndrome (HNPCC)

Question 23

Merkel Cells

Answer 23

Touch, tactile cells

Question 24

What should you do when biopsying a lesion to send the pathologist?

Answer 24

(1) Have to get a good sample & have a good description (history) sent to the pathologist
(2) Be overly descriptive for pathologist
- Never use terms like rash or lesion
- Be as descriptive as possible

THINK ABOUT DEPTH -take angriest looking biopsy sample - use punch biopsy if in doubt

Question 25

What type of biopsy should you do on a rash?

Answer 25

Punch biopsy!