An abdominal wall mass of exogenous insulin amyloidosis in setting of metastatic sarcoma.

Exogenous insulin amyloidosis (AIns) is an iatrogenic form of amyloidosis which is found in diabetic patients, generally localized to the site of subcutaneous insulin administration. It may form a discrete mass that could come to clinical attention, and can contribute to abnormal pharmacokinetics of the exogenous insulin, resulting in worsened control of diabetes. In this case report, we describe such a lesion in a 72-year-old man with a history of type 2 diabetes and primary adrenal gland epithelioid sarcoma and discuss the diagnostic challenges it poses.