Case Number : Case 1471 -12 February Posted By: Guest

So far makes me think of nodular subcutaneous amyloid. Another differential could be a Deep burn out pilomatricoma but i think it is less likely. I imagine the other pictures will show a whole different story...

Found this report also of subcutaneous amyloid secondary to subcutaneous insulin: Pharmaceutical amyloidosis associated with subcutaneous insulin and efurvitide administration. Amyloid 2014 Jun; 21(2): 71-75

I was also thinking of amylodosis. As Raul said there are numerous references about insulin related amyloidomas/ amyloidosis.

Agree with amyloid tumor. Not sure about insulin relation...thinking of plasmocytoid B-cell lymphoma related-amyloidosis.

Looks like a amyloidoma. But wouldn't be surprised if this is secondary to a burnt our epithelial tumour as Raul mentioned.....

I remember have seen one or two cases of amyloidoma during the residency with calcification and giant cell reaction. I wonder what is the others pathologists experience

Beautiful picture with apple-green birefringence

Amyloidoma. Still curious to know if it was located at an injection site.

Yes this could be either subcutaneous nodular amyloid (frequently AL type, usually not associated with systemic amyloidosis) but the calcification and giant cell reaction might be more in keeping with amyloidoma (of the extremities, usually AA type) according to Paternak et al Am. J. Dermpath. 2007;29:152-5.

I was not aware of diabetic injection amyloidomas (thank you).

This case was not local to me so I don't have follow-up and the anatomic location was not stated but the clinician did specifically state the lesion was NOT at the site of insulin injection.  There were scattered lymphoid aggregates and plasma cells appeared to be polytypic (within the usual technical limitations of the staining). I advised the patient should be worked up for consideration of systemic amyloidosis but commented this may be unlikely.