Case Number : Case 1775 - 17 March - Dr Richard A Carr Posted By: Guest

As we all celebrate St Patricks day why not take a few minutes out and have a look at this great set of images from Dr Richard A Carr.

 My impression in this case is that we see epidermal atrophy as well as some tagging of the basal layer and a sclerotic band pushing down inflammatory cells. On the other had in the dermis we see mainly a lymphocytic infiltrate that has a tendency to surround nerves as well as some macrophages surrounding some elastic fibers in last pict (elastophagocytosis?). I favour lichen sclerosus based on the images, which can be induced by radiation and can show elastophagocytosis (mainly in non genital sites), the clinical description is weird though. Probably would do some immunos to rule out lymphoproliferative and serial cuts as perineural inflammation can be a clue to a hiding neoplastic infiltrate. 

It could be postradiation lymphangiosarcoma as i can see vascular spaces with prominent endothelial cells plus perineural invasion by weired lymphocytes

This I find quite difficult. There are a few atypical cells there.  Given the Hx- high suspicion of cutaneous met from previous breast ca. Would like IHC please!

Difficult!

Thinking lymphoproliferative first (may be angioimmunoblastic lymphoma) which can present with intermittent rash... need IHC, will definitly do markers to exclude metastasis but feel it less likely because I can c some tagged lymphocytes and the dermal infiltrate looks more like atypical lymphocytes to me...

I was thinking about subacute radiation dermatitis. Tagging of lymphocytes along DEJ, subtle vacuolar change a few eos. However those perineural infiltrates are suspicious. I would do Pancytokeratin, D240, CD31 and a recut

Thinking of radiation recall dermatitis due to a presumptive triggering administration of intravenous trastuzumab. Clinical history of intermittent skin rash and microscopic findings fit well, but I’m not sure about perineural lymphocytic infiltrate.

I think radiation recall dermatitis is a great possibility. Not sure if this results in perineurial inflammation. 

Would also like to add a differential of extra genital lichen sclerosus- morphoea overlap.

I see a lichen sclerosus et atroficus. The above comments are very convincing and appropriate, but I don't know what thinking about in this case. So my spot diagnosis is: "I don't know"!

Caso complicado. Propuesta como diagnostico diferencial poiquilodermia.

Excellent discussion. I reported this as post-irradiation (early) morphoea (LS overlap). I did not do IHC. I have seen peri-neural involvement in morphoea several times now.  I don't think it's in the text-books but have not looked it up recently.

Postirradiation pseudosclerodermatous panniculitis can be histologically confused with both morphea profunda and lupus erythematosus profundus.