Case Number : Case 1774 - 16 March - Dr Arti Bakshi Posted By: Guest

Another neat treat of a case from Dr Arti Bakshi to get your brain cells working.

My spot diagnosis is granulomatous PPD but is hard to rule out drug related eruption just based on the histology as all the colleagues know. Clinical information should help. Does not look like sarcoidosis or infectious to me.

Agree, Granulomatous pigmented purpuric dermatosis.

Granulomatous dermatitis, favor granulomatous PPD... iron stain helpful

What about a granulomatous mycosis fungoides?

What about interstitial granulomatous drug reaction (dermatitis) - need more clinical history. Usually involves skin folds. 

I also thought of interstitial granulomatous drug reaction more than gran Pigm Purp Der... it needs clinical correlation

My first impression was Granulomatou PPD, second one was MF or even an unusual PPD-like MF. Need CPC.

Intraepidermal lymphocytes are twice large than dermal ones...

Good thinking Vincenzo... 

Second look on the photos, it could be MF yes... 

Dr Arti Bakshi has given me another half dozen images to upload, so take a look and see what you think now...

Geoff Cross - DermpathPRO Projects

I like granulomatous MF. Epidermotrophism with tagging along DEJ, atypical lymphocytes, wiry collagen, band-like infiltrate, Clinical could fit, differential drug but I didn't see necrotic keratinocytes 

Thanks Mona! 

After the new pictures agree with Vincenzo and the colleagues that suggested MF. Nice case

Granulomatous mycosis fungoides. After immunohistochemistry images, the task became less challenging, but nonetheless still challenging. Kudos for Vincenzo, who hit the nail on the head with only HE images.

This nicely illustrates the histologic overlap one can see between PPD and MF.  Also a lesson for me in resisting the power of certain features to draw the eye away from others, i.e red cells and histocytes distract from epidermotropism of lymphocytes.  Beautiful case! 

Yes, this is Granulomatous mycosis fingoides!

 The full clinical history was of patches and plaques thought to be consistent with MF on review by dermatologist. I accept I was a bit cheeky in the initial images as I purposely focussed on the granulomata, However, it is easy to get misled by these and ignore the real pathology in real life too, as pointed out nicely by Alice. So definitely a big 'well done' to Vincenzo for spotting the lymphoid atypia and tagging in the initial images...he clearly wins the prize for the sharpest eyes on this case!!

Thanks for all your valuable comments.

Forgot to add....many thanks to Dr Naveen Sharma for sharing this lovely case with me.