Chapter 7

Question 1

What are the three key features of lichenoid dermatitis?

Answer 1

1. Basal layer is destroyed
2. Civatte bodies
3. Sawtooth rete pattern

Question 2

True or False:

Lichen planus should not have parakeratosis or eosinophils.

Answer 2

True

• Lichen planus is like a strict parent: “You will not hang around eosinophils or parakeratosis.”
• Lichenoid drug eruption and remaining lichenoid processes are more permissive: “You don’t need to have eosinophils or parakeratosis, but if you want to, it’s OK.”

Question 3

What are the features of lichen planus?

Answer 3

• Lichenoid interface dermatitis
• No parakeratosis or eosinophils
• Sawtooth rete ridges

Question 4

What are civatte bodies?

Answer 4

Remnants of basal keratinocytes and pinched off bits of the basement membrane

Question 5

What are the features of lichenoid drug eruption?

Answer 5

• Lichenoid interface dermatitis
• Typically has eosinophils and parakeratosis

Question 6

What are the features of a benign lichenoid keratosis (BLK)?

Answer 6

• Lichenoid interface dermatitis
• Parakeratosis
• Stratum corneum NOT homogenous
• Solar lentigo commonly present at margin
• Earliest stage of evolution may show vacuolar interface dermatitis with a lymphocyte in every vacuole

Question 7

What are features of lichenoid graft-versus-host disease?

Answer 7

• Lichenoid interface dermatitis
• May have parakeratosis and/or eosinophils

Question 8

What are the features of hypertrophic lupus erythematosus?

What about on DIF?

Answer 8

• Lichenoid interface dermatitis
• May have eosinophils and parakeratosis
• Superficial and deep infiltrate
• Follicular plugging
• DIF → continuous granular band of IgG/A/M and C3 (full house) at BMZ

Question 9

What are the features of lichenoid regression of lentigo maligna?

Answer 9

• Lichenoid interface dermatitis
• Heavily sun-damaged skin
• Adjacent rete pattern may be effaced
• Parakeratosis and eosinophils may be present

Question 10

What are the features of a porokeratosis?

Answer 10

• Cornoid lamella → column of parakeratosis at 45-degree angle with underlying dyskeratotic cells
• Zone between cornoid lamellae may appear lichenoid or psoriasiform

Question 11

What are the three key features of vacuolar interface dermatitis?

Answer 11

• Intact basal layer (as opposed to lichenoid interface dermatitis)
• Vacuoles within basal layer
• Rounded rete pattern