Case Number : Case 1730 - 13 January - Dr Richard A Carr Posted By: Guest

Here is your Friday the 13th Special from Dr Richard A Carr with IHC images to be added at 6pm-ish GMT, I hope this is not too scary a case  :-)

Geoff Cross - DermpathPRO Projects

Clinical history and histological features ( lamellar fibrosis of papillary dermis, Pautrier abscess, linear lymphocytic infiltration of basal layer, atypical epidermal lymphocytes larger than intradermal ones ) make me favor Mycosis Fungoides. 

I also like MF/CTCL

Sites of the lesions are not the expected ones for mycosis fungoides, so maybe it is a spongiotic dermatitis with a few epidermotropic lymphocytes lined up along basal layer and a Langerhans microabscess in the fashion of a Pautrier simulant.

Agree with Robledo. Eczema, almost EAC like in image 1.

Erythema annulare centrifugum-like mycosis fungoides.

Ceyhan AM, et al. Australas J Dermatol. 2011.

Also thought of spongiotic dermatitis, the dermal infiltrate is quite prominent though.

I would love to c a CD3 and CD1a first to verify what we r seeing in the last image. A true Pautrier's microabscess or a Pautrier simulant. 

But provisionally, I am favoring a spongiotic reaction. To me, the epidermis is too spongiotic for MF and overall looks inflammatory.

The dermal infiltrate is quite dense though. Some coat sleeve impression. 

Some basilar lymphocytes?? Seems annular in configuration (since the ddx is GA). So may be it is EAC with pautrier's simulant. Waiting for the immunos!!!

I think this is a spongiotic dermatitis simulating MF with those Pautrier-like microabscesses. I would like to see immunostains for CD3 and CD1a as well, but at H&E it looks like langerhans cells. I agree with Mona´s observation that the clinical impression of GA may be a clue for EAC or contact dermatitis.

I like to rule out MF by IHC in this case.Although,spongiosis is too prominent to be MF.

Nice IHC pattern!

lt seems intraepidermal lymphocytes have loss of CD7 and CD8 neg . am i right?

so its more likely to be MF

Let me explain in details why favor MF over the other mimics:

1) the epidermal abscess is a true pautrier for me, because nucleus are hyperchromatic, lymphocytic, in opposite to vescicular and reniform of LC.  And the epidermal lymphocytes are twice large than dermal ones  

2) it's too important for me the "lamellar fibrosis " of papillary dermis. It isn't diagnostic off course but it's an useful clue to MF. 

3) 2/3 years of clinical history fit in with chronic disease than acute/subacute one ( like the lamellar fibrosis fit in better with a long time junctional epidermal dermal process  ). 

4) IHC isn't conclusive alone, but it fit very well in with the above, doesn't it?

Well done Vincenzo.  I agree with your diagnosis favouring mycosis fungoides (CD3+, CD4weak, CD7 loss, CD8-, clonal for TRG and TRB) currently being observed (pT1b skin limited disease). We can see spongiosis in mycosis fungoides although often the shear number of epidermotropic, hyperchromatic, lymphocytes remains disproportionate to the degree of spongiosis.  I agree with considering a Langerhan's cell pseudo-pautrier microabscess although Langerhan's cells typically have somewhat paler nuclei with more open chromatin and gentle folded (reniform) nuclei with more abundant pale eosinophilic cytoplasm (surprisingly could not find an example of such on dermpathpro - keep your eyes out though). I found the rather monotonous peri-vascular B-cells of some confusion, never having seen this pattern before so asked for B-cell clonality and this showed a weak polyclonal pattern). I'm guessing it was the latter pattern that led to some confusion with erythema annulare.

Well done Vincenzo, another thing learned today!

After immunohistochemical images, this is mycosis fungoides with odd clinical presentation and with odd microscopic features. Diseases definitively do not read Dermatopathology Textbooks!