Case Number : Case 2470 - 20 December 2019 Posted By: Dr. Richard Carr

Granulomatous inflammation with necrosis. I would consider ruling out mtb

Or may be Necrobiosis lipoidica. Zones of necrobiosis are too large for GA. Clinical correlation is important here. Of course in any granulomatous process and if clinical information is not clear, excluding infectious aetiologies is important as well as foreign body reactions.  

...or may be fungal...there are many eosinophils. But massive and tuberculoid necrosis makes me favor cutaneous tbc ( direct inoculation? )...

I believe this is Necrobiosis lipoidica. There are large areas of necrobiosis with some areas with a lasagna-like distribution of the inflammation and necrobiosis. The dermal fibrosis with horizontal collagen bundles is a tip as well.

I would go with infectious process.Epithelial hyperplasia is not a feature of palisaiding granulomas.

Extensive necrobiosis, giant cells with foamy histiocytes raise the possibility of necrobiotic xanthogranuloma. There's a focus of spongiosis with some eosinophils which may be due to contact sensitization caused by some local application. 

Pink necrobiotic granulomas with eosinophils. I would add to the differentials: medium vessel vasculitis including Churg-Strauss syndrome and Wegener’s Granulomatosis

Necrobiotic granuloma with deep extension, pseudoepitheliomatous hyperplasia and esinophils. In the 5th, 6th and 8th images there is a  fine black pigment ?? Black tattoo. So I would like to add to the differentails: necrobiotic granulomatous tattoo reaction mimicking necrobiosis lipoidica.

Eman is correct!!!! Brilliant. I with held the information that the reaction was localised to a tattoo. I suggested they did check for diabetes though. Interestingly the clinical stated keloid scar following red ink tattoo. I guess the red pigment had been "consumed".

Very good, Eman!

5 hours ago, Eman El-Nabarawy said:

Necrobiotic granuloma with deep extension, pseudoepitheliomatous hyperplasia and esinophils. In the 5th, 6th and 8th images there is a  fine black pigment ?? Black tattoo. So I would like to add to the differentails: necrobiotic granulomatous tattoo reaction mimicking necrobiosis lipoidica.

Excellent! 

Good job, Eman.

22 hours ago, vincenzo said:

Good job, Eman.

Thank u Vincenzo. Hope so!