Lichen Planopilaris: What’s important on Biopsy
LPP and AGA have MANY shared features!
There are many features of lichen planopilaris and androgenetic alopecia that are the same. Both conditions have perifollicular fibrosis although the degree of fibrosis may sometimes be more in LPP (but not always). Both conditions have inflammation. Not surprising … it’s easy to get confused.
Lichen planopilaris is a destructive process and ideally I like to have AT LEAST ONE PIECE OF GOOD EVIDENCE pointing to destruction, namely:
1) loss, reduction or at least atrophy of sebaceous glands or
2) death of hair follicle keratinocytes (lichenoid change or necrosis).
If I don’t have any of these two, I’d like the pathologist to help me figure out 3) if elastic tissue has been destroyed using some kind of elastin stain.
If none of these three features are present and clinically the story does not fit with scarring alopecia, we either need to abandon the original diagnosis or rebiopsy again to try to prove this is a scarring alopecia!!!!
I encourage doctors I work with to get in the habit of crossing out the words “perifollicular fibrosis” and “perifollicular inflammation “ in biopsy reports and seeing what information is left over. If the report seems strange or incomplete … one needs to call the pathologist for more information or rebiopsy!