Lupus Profundus(hyaljnizing subcutaneous fatty tissue and interstitial mucinosis. There are also many granulocytic-resembling dendritic plasmocytoid CD123+ cells. 

Lupus profundus- picture perfect

It is a very difficult case for me. At first glance it looks typical for Lupus profundus, as we can see superficial and deep dermal inflammation, lobular fat necrosis, mucin deposition, plasma cells and other findings. But in a closer look we can also see that the lobular necrosis is not the hyaline type, classic of lupus profundus. The clinical picture also demonstrates a female with lesions localizated at the lateral aspect of the thigh. So I am really in doubt about Lupus profundus x Cold associated perniosis of the thighs, a proposed term by Cerroni for the "equestrian cold panniculitis". In this condition we also see superficial and deep inflammatory infiltrates, some interface dermatitis, mucin deposition and vasculitis, but aparently there´s no such huge subcutaneous lobular necrosis. To complicate this subject, some cases of cold perniosis appears in patients with autoimune diseases, like Lupus. So, it is for me a very diifficult case and I am very anxious to se more comments.

Cold-Associated Perniosis of the Thighs ("Equestrian-Type" Chilblain): A Reappraisal Based on a Clinicopathologic and Immunohistochemical Study of 6 Cases.

Lupus panniculitis [ vacuolar interface/dermal inflammation/lymphoplasma cytic infiltrate/mucin and necrosis

I've asked Gerardo Ferrara to take a look at this case. Any other thoughts will be welcomed.

IgorSC - thanks for the helpful reference.

Gerardo Ferrara was kind enough to take a look and he comments as follows:

=======================

Rick... I am on vacation with limited means to get the net.
On the screen of my cell phone it seems a lupus panniculitis.
But the screen is tiny Indeed...

=======================

(BTW I'm Rick to my friends and often Ricardo to my Italian friends! and occcasionally ricardisimo!! if I've been a good boy)

This agrees with my report of a rather classic / textbook lupus panniculitis. I with held the following information (for fear of making the case too easy):

SLE with previous DLE forehead & Lupus profundus right shoulder & right buttock
Due to start azathioprine, on hydroxychloroquine. Dermovate.
Mixed connective tissue disease
Positive for U1-RNP antibodies.
Pain in joints & muscles
Panniculitis & DLE
Raynaud's

thanks sir for sharing wonderful text book case

Thank you for the comments, Dr. Richard. The "granular" necrosis, the outer thigh localization and my recent reading of this papper made me think something different, but the other clinical and laboratory findings are consistent with Lupus profundus. Anyway, it is always nice to have these kind of cases to be allert to other possibilities.

Degos?