Case Number : Case 1904 - 14 Sept - Dr Arti Bakshi Posted By: Guest

Predominantly compact brightly eosinophilic orthokeratosis (with a possible foci of parakeratosis at right edge) overlying a discrete area of atrophic epidermis with complete effacement of rete ridges. A band-like lichenoid infiltrate + some activated looking irregular lymphocytes immediately beneath it. Papillomatous spires especially more noticeable on the left side of the image.

To me, this looks like a Flegel's disease (Hyperkeratosis Lenticularis Perstans), aware it is a rare disease. Kyrle's disease can share some features with this condition as well but less likely in the current case.

Alternating hyper and orthokeratosis, alternating acanthosis and atrophy of stratum malpighi along with dense band of dermal lymphocytic infiltrate and vacuolar changes in basal cells suggest keratosis lichenoids chronica. Can't rule out Flegel's though.

When I first saw the images I thought of keratosis lichenoides chronica. However, I did not consider Flegel's (have seen only one case before in Richard Carr's amazing collection) so agree, should add Dr. Fatah's great diagnosis as a differential

I didn’t know too much about this disease, but thank s to all of you I’m learning something and as far as I can understand agree with Fatah. Great case. 

Agree- looks like Flagel's

First thought was Flegel's too 

Thanks Raul (is your memory photographic?). My pretty simultaneous "spots" were same as yours. Hope it is KLC then I can ask Arti for some copy sections as I don't have a case in the collection.

Dear All:

It is very interesting to hear Dermatopathologists like Dermatologists relies heavily on visual memories of slides or patterns to reach a possible diagnosis/diagnoses, which will be refined and expanded continually with experience.

KLC remains a challenging and enigmatic disorder, thanks for teaching me Nekham can have similar histology features.

We will wait for Arti for her final thoughts/feedback as CPC is crucial including family history.

For those keen on learning more on Flegel's, this link is a valuable reference written 30 years ago describing various stages of histology depending on the age of lesion.

https://www.ncbi.nlm.nih.gov/pubmed/2439113

Great discussion and well done to Saman for the diagnosis and her educative comments.  

This is Flegel's disease...my very first and only case!...The only other case I have seen was in Richard's collection too.

This patient had typical clinical lesions. No family history that I am aware of. There was no linear/reticulate pattern (seen with clinical lesions of KLC)  nor was there any facial seborrhoeic dermatitis.

The histology fits very well with Flegel's. The discrete and well demarcated area of hyperkeratosis overlying an attenuated epithelium is a characteristic feature. Image 4 shows the sharp border between compact hyperkeratosis and the adjacent normal keratin layer. The band like dermal infiltrate completes the picture.

Sorry, Richard, your wait for a case of KLC continues....

Flegel's disease