Case Number : Case 2305 - 15 April 2019 Posted By: Limin Yu

granulomatous inflammation with necrosis

special stains for MTB/fungus needed

perforating GA?

This looks like a perforating dermatosis with acanthosis around a transepidermal elimination canal. What is being eliminated from the dermis maybe altered collagen or mucin. I favour perforating papular mucinosis. 

Appears to be perforating necrobiotic granulomas: Deep GA, Rheumatoid nodule. Will also perform Fite for atypical mycobacterial infection. 

Looks like a cat scratch disease...but in this site should be very odd.

I think the kind of necrobiosis is more like the "fibrinoid-type". The granulomas also came from the deep of the biopsy, so I believe this is perforating rheumatoid nodule.

Agree with many of the above comment. Neutrophils in the necrobiotic areas, would first rule out infections. If stains and cultures are negative, then deep GA or rheumatoid nodule.

Great differentials and agree it seems more fibrinoid (at least to my eyes). Definitively I would perform special stains and if these are negatives I favor Rheumatoid nodule over GA.

10 hours ago, John Zhang said:

Agree with many of the above comment. Neutrophils in the necrobiotic areas, would first rule out infections. If stains and cultures are negative, then deep GA or rheumatoid nodule.

10 hours ago, IgorSC said:

I think the kind of necrobiosis is more like the "fibrinoid-type". The granulomas also came from the deep of the biopsy, so I believe this is perforating rheumatoid nodule.

Agree with both. The appearance is infectious but it could really be a reumatoidi nodule.  

Can we add epitheloid sarcom to the differential?

Perforating rheumatoid nodule is my first thought. Epithelioid sarcoma to be R/O but cells do not look atypical from this power

sir whats the final diagnosis

Looks palisaded granulomatous and necrobiotic. I would go for rheumatoid (or pseudorheumatoid / deep GA nodule).