Case Number : Case 2917 - 10 September 2021 Posted By: Dr. Richard Carr

To me appears like a tiered pattern of necrobiosis and fibrosis, with few giant cells and aggregates of plasma cells. Pigment at the top likely to be hemosiderin. I am thinking of necrobiosis lipodica. 

51 minutes ago, Meenakshi Batrani said:

To me appears like a tiered pattern of necrobiosis and fibrosis, with few giant cells and aggregates of plasma cells. Pigment at the top likely to be hemosiderin. I am thinking of necrobiosis lipodica. 

Yes. Difficult case for me, because the stratified layers of necrobiosis don’t appear striking, but Necrobiosis Lipoidica was my first thought too. 

Found this: https://www.researchgate.net/publication/7966125_Light-chain-restricted_plasmacellular_infiltrates_in_necrobiosis_lipoidica_-_A_clue_to_an_underlying_monoclonal_gammopathy. 

These are Kappa & Lamda as Vincenzo as worked out and the patient does have a monoclonal gammopathy. Are there any other diagnostic considerations in this setting other than NL?

Necrobiotic xanthogranuloma

Yes me too! Necrobiotic xanthogranuloma seemed to fit all the clinico-pathological features best and there are some quite striking multinucleate cells. Patient had a longstanding MGUS and localised restriction on Kappa / Lambda. I did initially suggest NL until the clinicians revealed the MGUS which was not supplied on the request form so please don't blame me for being difficult! The patient was not diabetic. 

Very interesting case, Richard. Thanks. 

Thanks for this case sir

are touton giant cells/cholesterol clefts needed or not necessary in diagnosis of NXG

They are seen in the classic cases but I guess there must be variants such as this that sit between stools.