Case Number : Case Number : Case 1858 - 12 July - Dr Iskander Chaudhry (Invited) Posted By: Guest

Morning all - new case added!

epidermal hyperplasia, suprabasal clefting. can't see any intraepidermal collection of eosinophils or polys. not sure if there is any definite dyskeratosis in the left hand field of image 3. so thinking on lines of pemphigus vegetans, Darier's (which may have a localised/segmental variant?)

SYRINGOCYSTOADENOMA PAPILLIFERUM. 

Axilla is an odd location, but I found this:

A case of zonal syringocystadenoma papilliferum of the axilla mimicking verruca vulgaris.
Xu XL, et al. Am J Dermatopathol. 2010.
 

Acantholytic dyskeratotic acanthoma ?

I Am confused based on the these images. Some areas look papillary in pic 2 SCP-like but it is hard to interpretate. I think this is more consistent with acantholytic acanthoma,

given tha it is a solitary lesion, i agree, it would be in keeping with acantholytic acanthoma

Although the inflammatory infiltrate is not as intense and eosinophils-rich as it would be expected, pemphigus vegetans deserves consideration. Axilla is a typical site, and subtle suprabasal acantholysis of both pseudoepitheliomatous hyperplastic epidermis and infundibular follicular epithelium are characteristic microscopic features.

Pemphigus vegetans was my "spot". Liked some of the other suggestions.

P Vegetans would be top on my list too.

P vegetans my first thought

Prominent acanthosis, suprabasal clefts and very few acantholytic cells within the lacunae. Lack of significant inflammatory infiltrate within the epidermis/superficial dermis is striking feature (especially eosinophilis) in otherwise well circumscribed flat based lesion. History mention a lesion rather than an eruption making acantholytic acanthoma or other benigin epidermal proliferations with acantholysis slightly more favourable to me. Immunobullous is in the differential including P. Vegetans but the latter is a rare disease and CPC is essential in this context. 

Good point about the "lesion" comment and lack of eosinophils!

Thanks all !

It was in fact P. Vegetans - had supporting IMF and also lesions elsewhere.

Iskander

Interesting update on this case, thanks. It reinforces some limitations of H&E patterns and pauci-cellularity was a good learning point for me or perhaps one need to beware of the sin of diagnostic greed!