Case Number : Case 2037 - 27 March 2018 Posted By: Dr. Richard Carr

Granuloma annulare.

Agree!!!

There are foci of necrobiosis with palisading but other unusual things are the epidermal pallor and superficial location of necrobiosis. Secondly, psoriasis and lichen planus, mentioned in clinical DDs don't resemble GA clinically. I think this is another googly from Dr Carr!  Could be a nutritional dermatosis

It is rectangular punch with horizontal rows of palisading granulomas with necrobiosis . I am seeing some lymphoid  With ?Plasma cells at the lower edge of the lesion ! 

I am more with Necrobiosis Lipoidica. ( always prefer to do a mucin)

When I see a histopathologic - clinical discorrelate, I always think of drug. The lack of significant eosinophils does not dissuade me. I like nutritional deficiency too, Anil! Good thought.

Well I'm glad this case caused you some difficulty and sincerely it (the googly) did me too! Googly is a cricket term for a ball delivered that behaves in the opposite way to what your normally expect the bowler to deliver.

Clearly you are all used to my googly!  I suppose we should ask when is necrobiosis not necrobiosis. Perhaps this is pseudonecrobiosis - may be an awful section that I'm embarrassed to share with you but this is what was delivered.

Interestingly I'd diagnosed superficial naked granulomas on 2 of the 3 levels and opted for sarcoidsosis (on blind review) but was held back by my then visitor who said he thought there was necrobiosis in level 1 (what you see here photographed). We reviewed the clinical and the patient did indeed have some lesions that looked like sarcoid (apple jelly lesions). Incidently the patient is an affluent professional and I suspect unlikely to have a nutritional issue. We came across several old papers referring to patients who had both sarcoid & granuloma annulare. There was a picture in Akerman's famous original book on the inflammatory dermatoses of a sarcoidal granuloma in GA although interestingly the same case did not make it in to the 2nd or 3rd books!

I shared the case digitally (including clinical images) with Werner Kempf in Zurich as follows:

Dear Richard
Thank you for this interesting and challenging case. On one hand there are changes compatible with subacute eczematous and pruriginous reaction considering the epidermal changes and the clinical features. I am not sure whether the changes in the subepidermal compartment in fact represent a necrobiotic area or just the result of the irritation. I would primarily prefer sarcoidosis in combination with eczema. I do not find clear-cut signs of granuloma annulare as I would expect a different pattern of histiocytic infiltration as well as focal necrobiotic areas also in the mid dermis.
I hope that this helps a bit. I am looking forward to more photomicrographs.
Best wishes,
Werner

Hi Werner,
Many thanks for you input.
Deepers show only the sarcoidal granulomas. [mucin was negative]
Think you are right it’s not GA!  Just a mimic in not very good sections!
Regards
Richard

Hope you enjoyed the googly!

It was not just a googly but a yorker Dr Carr!!