Case Number : Case 761 - 17th May Posted By: Guest

Mucinous metaplasia of the vulva in association with plasma cell mucositis

I agree with Dr. Sezer: mucinous metaplasia arising within Zoon's vulvitis.

Zoon's vulvitis with mucinous metaplasia.

Agree with everyone. Very nice case!

[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4]Zoon's vulvitis[/size][/font][/color]

A dense band-like infiltrate predominated by plasma cells. There is also epidermis thinning and mucinous metaplasia. I agree with my colleagues opinion of Zoon's vulvitis (vulvitis circumscripta plasmacellularis).
Is this paper from you, Dr. Carr?
Thomson MA, Carr RA, Ganesan R, Humphreys F. Extensive mucinous metaplasia of the vulva arising within Zoon's vulvitis. Br J Dermatol 2007;156:750-752.

[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4]Zoon's vulvitis. [/size][/font][/color]Nice case. Some of the keratinocytes next to the big goblet cells [in bottom left photo] show early metaplasia, with just a few basophilic mucin granules and absence of nuclear indentation.

Well done. It amazes me sometimes that sometimes, even when there are literally only a few cases in the world literature that a diagnosis can be so well known and easy for you all. Yes that is our paper but this is a different case. I have now collected four examples (of mucinous metplasia) all in association with the Zoon's reaction pattern. I say the Zoon's pattern because it seems the prevailing view is that the vast majority of Zoon's are either lichen scleruosus or lichen planus in which the diagnostic features of those more specific dermatoses have not been biopsied. An expert clinician with an interest in vulval (genital) dermatoses who biopsies the right area can usually provide a more specific diagnosis and I have recently experienced that in another case in which one biopsy showed classic Zoon's reaction pattern and a second simultaneous biopsy showing a clear-cut lichenoid dermatosis (either lichen planus or lichen sclerosus). So when you see the Zoon's pattern (often has moderate haemosiderin deposition in the corium) look out for subtle mucinous metplasia (as seen here) and you will often find it. Don't confuse it with Paget's in which the you will see the classical Pagetoid arrangement of the atypical cells on Cam5.2 or CK7 throughout all layers of the epithelium. In contrast mucinous metaplasia when fully developed has cuboidal to collumnar cells on the surface (right hand figure second down). The mucin in the cytoplasm can be subtle but a good haemotoxylin (as in the case illustrated here) will show it nicely even in incomplete cases like this one. In fact "collumnar mucinous metaplasia" would be a nice term to use for these cases.

Apologies for the delay in positng. I was involved with the London Dermpath Symposium (but had to leave early on friday afternoon to start a golfing holiday). A very good meeting it was too with a chance to sit at the multi-header with leading experts, microscope based self-assessment course of wonderful range of cases, mini-sypmosium of dysplastic naevus with cases available to participants online and at the meeting in an attempt to acheive more consensus, varied lectures and scientific presentations (including our series of 50+ tricholemmomas highlighting the basaloid variant and some interesting new research in melanoma). Mark Hurt debated with Alistair Robson: "This house believes dysplastic naevus is a useless diagnosis that should be dropped from useage". I can recommend this meeting to you all for next year.
Enjoy the rest of your weekends and regards from Dessert Springs Golf Resort in Spain (amazing golf course and practive facilities!)