Case Number : Case 2020 - 03 March 2018 Posted By: Dr. Richard Carr

The salient features are epidermal atrophy, hydropic degeneration of basal cells, thickened BMZ, lympho- plasmacytic infiltrate in the dermis with mucin. Dermal vacuolization is rather prominent. I think this is chronic DLE.

Forgot to include incontinence of pigment

Would like To know what is in those vacuoles. Two year History so probably  not infection. Any injection at this site for cosmetic purpose ? Breast implants in the history?

Dermal mucinous fibrosis with nodular lymphoid infiltrate in an over 60th---->>Desmoplastic Melanoma is my first spot.

Furthermore pictures 2/4/5 show a DEJ impressive for a regression..

Wold like to see a S100 stain!

32 minutes ago, vincenzo polizzi said:

Dermal mucinous fibrosis with nodular lymphoid infiltrate in an over 60th---->>Desmoplastic Melanoma is my first spot.

Furthermore pictures 2/4/5 show a DEJ impressive for a regression..

Wold like to see a S100 stain!

....but now many doubts about this lesion.  The pigment looks like tattoo...

I agree the pigment looks like tattoo. It may be a lichenoid tissue reaction to tattoo.

It has more to it than what meets the eye. Is it a tattoo reaction treated with corticosteroid injection? But then why should it bleed and scab?

To me the responses to this case is very instructive of how we approach things.  There is a tendancy for us to try to make a diagnosis in every case.  It's called an error of commission. Trying to be helpful by thinking every case can be diagnosed.  Please look at the clinical again and ask yourself how likely it is the patient has DLE or has been injected on the nose on has a desmoplastic melanoma?  IHC was done on the case and was re-assuring.  The bottom line is there is no BCC or other tumour seen after careful examination. If we want to speculate in the report we should make it clear we don't know for sure but for example it could represent an inflammatory regression reaction to previous tumour (sometimes a pan-keratin can demonstrate the colloid bodies) with pigment incontinence. Alternatively there may have been a ruptured cyst or comedone.  The "fat-like" spaces are called pseduolipomatosis cutis (reference cited in Weedon) and I would regard it as a reaction pattern with speculative causes as above.

I agree that it makes sense to post from time to time, cases for which (as my mentor used to say) "there is no answer in the envelope". I encourage my fellow lovers of dermatopathology to consider a differential diagnosis in all posted cases and to formulate a diagnostic approach to these cases. It's such a useful exercise and I promise that it will help 'in real life'. Thank you Dr. Carr for this very instructive case. 

On ‏٠٥‏/‏٠٣‏/‏٢٠١٨ at 13:12, Dr. Richard Carr said:

To me the responses to this case is very instructive of how we approach things.  There is a tendancy for us to try to make a diagnosis in every case.  It's called an error of commission. Trying to be helpful by thinking every case can be diagnosed.  Please look at the clinical again and ask yourself how likely it is the patient has DLE or has been injected on the nose on has a desmoplastic melanoma?  IHC was done on the case and was re-assuring.  The bottom line is there is no BCC or other tumour seen after careful examination. If we want to speculate in the report we should make it clear we don't know for sure but for example it could represent an inflammatory regression reaction to previous tumour (sometimes a pan-keratin can demonstrate the colloid bodies) with pigment incontinence. Alternatively there may have been a ruptured cyst or comedone.  The "fat-like" spaces are called pseduolipomatosis cutis (reference cited in Weedon) and I would regard it as a reaction pattern with speculative causes as above.

Great comment!