Skin neoplasms

Question 1

List the normal layers of the epidermis and the cell types of the epidermis.

Answer 1

S. corneum, S. lucidum, S. granulosum, S. spinosum, S. basale.
Cell types include keratinocytes, basal cells, melanocytes, and Langerhan’s cells.

Question 2

List some tumours of keratinocytes.

Answer 2

Epidermal (sebaceous) cyst.
Actinic (solar) keratosis.
Squamous cell carcinoma.
Keratoacanthoma.

Question 3

Briefly describe an epidermal cyst.

Answer 3

Epidermal (sebaceous) cyst: a cyst of keratin debris lined by benign squamous epithelium, found in the dermis.

Question 4

Briefly describe actinic (solar) keratosis.

Answer 4

Actinic (solar) keratosis: hyperkeratosis with dysplasia limited to the epidermis.

Question 5

Briefly describe squamous cell carcinoma.

Answer 5

Squamous cell carcinoma: nodular, scaly and ulcerated lesion on sun-exposed sites with invasion beyond BM.

Question 6

Briefly describe keratoacanthoma.

Answer 6

Keratoacanthoma: a benign, rapidly dividing neoplasm that may spontaneously regress, appearance similar to a crater, nodular with center of keratin.

Question 7

List some tumours of basal cells.

Answer 7

Seborrhoeic keratosis.

Basal cell carcinoma.

Question 8

Briefly describe seborrhoeic (senile) keratosis.

Answer 8

A benign, raised warty lesion, seen in the elderly. Microscopically has a proliferation of basal cells with keratin nests.

Question 9

Briefly describe basal cell carcinoma.

Answer 9

malignant neoplasm, most common in Australia, related to sun exposure. Sloe destructive growth, appears as a pearly nodule or papule with surface telangiectasia. Microscopically has malignant basal cell hypertrophy with peripheral palisading (like a picked fence), apoptotic debris and retraction artefact or clefting.

Question 10

List some tumours of melanocytes.

Answer 10

ephelis (freckle);
lentigo;
naevocellular naevi (mole) - junctional, compound, or dermal;
melanoma.

Question 11

Briefly describe a ephelis.

Answer 11

A freckle. Benign, present since childhood, small pigmented macule that darkens after sun exposure. There is normal melanocyte number but increased pigment in basal layer.

Question 12

Briefly describe solar lentigo.

Answer 12

A benign lesion that occurs in all ages, a pigmented macule that does not darken on sun exposure.
There is linear melanocyte hyperplasia.

Question 13

Briefly contrast ephelis to lentigo.

Answer 13

In ephelis there is a normal melanocyte number but increased pigment, but in lentigo there is linear melanocyte hyperplasia. Ephelis darkens after sun exposure whereas lentigo does not.

Question 14

Briefly describe naevocellular naevi.

Answer 14

Moles can be congenital or acquired benign neoplasms of melanocytes. They are uniformly pigmented and can be macular or popular. There are three main types, junctional, compound, or dermal.

Question 15

Compare and contrast junctional, compound, and dermal naevi.

Answer 15

All are benign. Junctional in children, compound in young adults, dermal in adults. Junctional within the epidermis, compound across both epidermis and dermis and slightly raised, dermal only within dermis and often nodular or pedunculated.

Question 16

Briefly describe melanoma.

Answer 16

A malignant tumour of melanocytes, related to UV exposure. growth can be superficial spreading (in situ or invasive), or nodular. Prognosis depends on wether in situ or invasive, depth of invasion, ulceration, mitotic rate.

Question 17

Briefly describe the Clark Level criteria for assessing anatomical depth of a melanoma.

Answer 17

Clark Levels:

1: epidermis
2: papillary dermis
3: junction of papillary and reticular dermis
4: reticular dermis
5: subcutis

Question 18

Briefly describe Breslow’s thickness.

Answer 18

A measure of the depth of invasion of melanoma according to mm measured. There is a worse prognosis for a depth >0.75 mm.

Question 19

What does ABCDE stand for in comparing a melanoma to a benign naevus.

Answer 19

A: asymmetry
B: border
C: colour variation
D: diameter
E: evolution/elevation

Question 20

Briefly describe Paget’s disease of the nipple.

Answer 20

An in situ malignancy of the nipple from underlying breast carcinoma or ductal carcinoma in situ with eczema like changes as malignant cells extend from the nipple ducts into the epidermis.

Question 21

List some neoplasms of the dermis.

Answer 21

Dermatofibroma, neurofibroma,haemangioma, angiosarcoma, adenoma, lipoma, lymphoma, sebaceous lesions: naevus sebaceous, sebaceous adenoma, sebaceous carcinoma.