Case Number : Case 738 - 15 Apr Posted By: Guest

Follicular LP/LPP

Follicular LP

Infundibulocentric lichenoid infiltrate of lymphocytes, infundibulum plugged by corneocytes, incipient wedge-shaped infundibular hypergranulosis and scattered necrotic keratinocytes. Interfollicular epidermis is spared. Absence of mucin between collagen bundles.
I favor lichen planopilaris.

lichen planopilaris

LP/follicular LP vs lichenoid keratosis

Lichen planopilaries

lichen planopilaris

Lichen planopilaris is correct. The clinical history of multiple lesions on the back excludes lchenoid keratosis.

Why is it not POROKERATOSIS,

[quote name='Guest' timestamp='1366049008']
Why is it not POROKERATOSIS,
[/quote]
I'm afraid to say that porokeratosis is not a good diagnostic hypothesis.
Clinically, porokeratosis tend to appear in childhood or young adulthood, and our patient here is 59 years old. Back is not a typical site for this disease, but extremities and, less frequent, sun-exposed areas. Furthermore, case history is not consistent with the characteristic gross configuration of porokeratosis, to wit, annular lesions with keratotic rim.
Microscopically, infundibular plugging is not a feature of porokeratosis, and the common denominator of all variants of this disease (cornoid lamella) is lacking.