Chapter 5

Question 1

According to Elston, what looks like a clonal seborrheic keratosis but has ducts?

Answer 1

Hidroacathoma simplex

Question 2

What is the diagnosis for the following phrase: “Blue islands floating in a sea of snot”?

Answer 2

Mucinous carcinoma

Islands of blue cells surrounded by mucin

Question 3

According to Elston, “what is a syringoma from hell?”

Answer 3

Microcystic adnexal carcinoma (MAC)

• MAC differentiates as pilar and sweat
• Sclerosing sweat duct carcinoma is a subtype of MAC (“a sweaty MAC”) → differentiates only as sweat; “monophasic” → only has pink “paisley tie” islands (not blue islands like in MAC)

Question 4

What are the histologic features of a hidrocystoma?

Answer 4

• A simple sweat duct cyst with cuboidal epithelium
• Can be stretched out

Question 5

What is the primordial sweat gland, according to Elston?

Answer 5

Apocrine glands

Answer 6

Also known as a chondroid syringoma

Anastomosing strands surrounding myxoid stroma

Has mesenchymal elements and epithelial elements