Case Number : Case 1938 - 02 Nov - Dr Arti Bakshi Posted By: Guest

Difficult. Bcc-like stromal retraction. Irritated sk-like features. But there’s something more impressive to my eyes: panfollicular differentiation, including matrichal, m.p.b., infundibular differentiation...my spot is epidermal type panfolliculoma ( but it’s first time I make this diagnosis so am afraid I’m wrong)

Favor inverted follicular keratosis. 

Intraepidermal proliferation of cuboidal cells with squamous eddies; basically an irritated seborrheic keratosis with inverted growth pattern (growing along the hair follicle or showing follicular differentiation).

Less common location, sebaceous lobules at the periphery are less common, and grouping appears unusual in my limited experience, but still comes closest to IFK.

I was thinking poroma vs. inverted follicular keratosis. I favor poroma.

By the way, I have posted the diagnosis for yesterday's case. Sorry for the delay!

Hi All. I like the suggestion of poroma but the cells dont have the classic poroid appearance and no ductal differentiation is apparent. Some sections show a vague palisade, squamous eddies and 'follicular' differentiation.

I agree with the diagnosis of inverted follicular keratosis showing follicular differentiation. 

Dear all I havre also posted my post diagnosis from last week 

I thought of SEBK (inverted follicular keratosis)

Agree with inverted follicular keratosis.i think we have eddies.

IFK mostly

My differentials were the same as above....a poroma with follicular differentiation vs inverted follicular keratosis. The architecture was poroma like but the cells were not particularly poroid. The frequent squamous eddies and lack of ductal differentiation made me favour an IFK too.

Well done all!