Friday 2 - Jokinen - Dermatopathology

Question 1

Vitiligo vs Albinism

Answer 1

V - autoimmune lymphocyte mediated melanocyte destruction

A - congenital absence of tyrosinase

Question 2

Melasma

Answer 2

Mask like facial hyperpigmentation. results from pregnancy, oral contraceptives.

Question 3

Solar lentigo

Answer 3

Hyperpigmentation of basal epidermis due to excess melanin production. (sun protective mechanism)

Question 4

Lentigo simplex

Answer 4

localized hyperplasia of melanocytes, not sun related

Question 5

Nevus. Most common mutation in them.

Answer 5

Mole. benign neoplasm of melanocytes. BRAF

Question 6

Blue nevi

Answer 6

Look like a cancerous melanoma, but are benign.

Question 7

Spitz nevi

Answer 7

Difficult to distinguish from a melanoma under microscope. All should be excised.

Question 8

Halo

Answer 8

Immune reaction to nevus cells

Question 9

Dysplastic Nevus

Answer 9

Means atypical. Potential precursor of melanoma. Multiple = marker of increased risk of melanoma

Question 10

Nevus of Ota/Ito

Answer 10

Ota: peri-ocular, intra-ocular dermal melanocytic nevus
Ito: mongolian spot, same type of lesion, but usually on the back

Question 11

ABCD

Answer 11

Grading for melanoma
Asymmetry
Border
Color
Diameter (>6mm is bad)

Question 12

Breslow’s depth. Survival rates?

Answer 12

BEST way to know probability for a melanoma to metastasize.
Depth on invasion into the dermis measured in mm.

5-year survival
<1mm: 95-100%
1-2mm: 80-96%
2.1-4mm: 60-75%
4mm: 37-50%

Question 13

When do you try a sentinel lymph node biopsy

Answer 13

When a melanoma is >1 mm in thickness

Question 14

Seborrheic keratosis

Answer 14

Common epithelial neoplasm. Trunk, head, neck are typical sites. Sharply demarcated, lots of keratin.

Question 15

Acrochordon

Answer 15

skin tag

Question 16

Actinic keratosis & how it’s treated

Answer 16

benign neoplasm of epidermis caused by sun exposed skin. rough spots on skin.

Treated via liquid nitrogen, curretage, topical chemo.

Question 17

Basal cell nevus syndrome

Answer 17

Dominant inheritance. Rare. BCC at early age

Question 18

Adnexal proliferation/Neoplasms

Answer 18

Differentiation of tissue toward hair follicle, eccrine, sebaceous, and apocrine glands.

Question 19

Cowden’s syndrome. Where? mutation in what?

Answer 19

Heriditary condition prone to multiple hamartomas and malignancy.

Skin: multiple trichilemmomas (benign proliferation of hair follicle epithelium).
Internal: breast, endometrial, and thyroid carcinoma

Mutation in PTEN

Question 20

Muir-torre syndrome (MTS). What is it and when and how do you test for this?

Answer 20

Germline mutations in DNA mismatch repair proteins MLH1, MSH2.

Gives rise to sebaceous adenoma and carcinoma

Young/adult patient with sebaceous adenoma or carcinoma, test for MTS via immunohistochemistry.

Question 21

Merkel cell carcinoma, what causes it?

Answer 21

Aggresive epithelial neoplasm. Most caused by polyomavirus.

Question 22

Dermatofibroma

Answer 22

Dermal proliferation of histiocytes and fibroblasts. Tan brown firm papules.

Question 23

Dermatofibrosarcoma Protuberans

Answer 23

Well differentiated fibrosarcoma of skin, rarely metastasize, storiform bland spindled cells.

Question 24

Hemangioma

Answer 24

Well formed vascular spaces in dermis (benign). Strawberry mark.

Question 25

Langerhans cell histiocytosis

Answer 25

Langerhans cells (dendritic cells) infiltrate the skin.

Question 26

Leukemia Cutis

Answer 26

Spread of leukemic cells to the skin.

Question 27

Cutaneous t cell lymphoma

What does it look like in early stages

Answer 27

T cells arise in marrow and travel to skin. Looks like psoriasis, eczema, etc. in early stage. Lots of plaques.

Question 28

Mycosis Fungoides

Answer 28

Most common type of Cutaneous t cell lymphoma (CTCL). Neoplastic cell is CD4+ T cell.

Question 29

Cutaneous b cell lymphomas

Answer 29

Less common that CTCL. Usually solitary nodules.