These deposits have the characteristic waxy appearance of amyloid. Additional studies would include thioflavin T stain (fluorochrome dye) for confirmation of amyloid. Congo red could also be done. Nodular amyloidosis implies a localized, tumor-like deposit not associated with systemic disease but it may be necessary to first do a clinical workup for systemic amyloidosis and also do immunophenotyping of the deposit using antibodies to kappa, lambda, Anti-AA, and Anti-prealbumin before reaching that conclusion. Anti-amyloid substance P could also be done. In my experience, this is quite rare. I can only recall seeing two previous patients with nodular amyloidosis. There is one patient in the clinic that is currently being followed by hematology and dermatology over the last 3-4 years,who seems to have localized nodular amyloidosis.