Case Number : Case 896 - 25th November Posted By: Guest

[font=tahoma,geneva,sans-serif][b]Mucin deposition ?? may consider granuloma annular ;interstitial type..[/b][/font]
[font=tahoma,geneva,sans-serif][b]A bit difficult without clinical description for the lesions.[/b][/font]

Mucin deposition associated with an increased number of fibroblasts, some of them multinucleated.
I think this is Papular mucinosis.

dermal mucinosis. primarily papular mucinosis

[b]Agree with papular mucinosis[/b]

Agree with papular mucinosis

Localized lichen myxedematosus (papular mucinosis). There is fibroblast proliferation and mucin deposition in the upper dermis, particularly pronounced in the subepidermal zone. Fibrosis is insufficient to scleromyxedema.

I will add macular mastocytosis (TMEP) to the differential. There is an increased number of subtly granulated mononuclear cells and a few rare stellate multinucleated cells, although the resolution limits make it difficult to differentiate the latter's lineage (mast cell, plasma cell, fibroblast).

Papular mucinosis

[size=4]Ooops, this is vitiligo. No melanocytes nor melanin pigment were highlighted.
But what about the bluish material splitting collagen fibers in the upper dermis? Maybe it is l[/size][font=arial, verdana, tahoma, sans-serif][size=4]ocalized lichen myxedematosus involving an area of previous known vitiligo..[/size][/font][color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4].[/size][/font][/color]

Indeed- looks like vitiligo. However I am a bit puzzled like everyone else with the dermal changes. Are these incidental??

It is indeed quite amusing to see the entire dermpath community on the website being fooled by this case. Having said that Vitiligo is certainly not a histological diagnosis as CPC is always required and essentially it is a diagnosis of exclusion: [url="http://www.ncbi.nlm.nih.gov/pubmed/18613870"]http://www.ncbi.nlm.nih.gov/pubmed/18613870[/url].

Do remember that in the groin/ mucosal area, histology is often required to rule out Vitiligoid Lichen Sclerosus: [url="http://www.ncbi.nlm.nih.gov/pubmed/18388368"]http://www.ncbi.nlm.nih.gov/pubmed/18388368[/url]

Indeed Dr. Hurt, that is what I meant. Certainly did not mean that 'you' had tried to fool us. I was referring to the 'case' having fooled us. Apologies if I came across differently. Vitiligo is considered in the differential of 'invisible dermatoses' (though in the early stages- the features are inflammatory, lichenoid). However in this case, something else was visible which made us all go off on a tangent. We do often see associated features in various dermatoses and neoplasms. However, when we know the history and feel that the associated changes are of no clinical relevance, we sub-consciously or consciously ignore these changes, for the sake of not confusing the clinician. In this case, without the knowledge of the clinical request- we all concentrated on the 'associated' change!

Blind reporting is certainly the way I was taught and is the best practice. It makes us think; In this case- I wondered, if there is indeed some mucin in the dermis (which you might not have tested for), does the patient have associated myxedema (related to another autoimmune, thyroid disease)?

Of course it is easy to also imagine things when we are looking blind and I have often made a complete fool of myself (even in not so invisible dermatoses!). But, I am sure we would all be interested to know the status of the dermal mucin in this case.