Hyperplastic Autotransplanted Parathyroid Tissue Migrating into Fatty Tumor after Total Parathyroidectomy

Secondary hyperparathyroidism (SHPTH) occurs commonly in patients with end-stage renal disease (ESRD). Uncontrolled SHPTH is associated with complications of calcium deposition including calciphylaxis and elevated rates of cardiovascular morbidity. Current treatment recommendations for medically refractory disease include total parathyroidectomy, often with autotransplantation (TPTH+AT) of minced parathyroid gland. Surgical intervention is associated with a reduction in cardiovascular mortality. We report a case of a 56-year-old man with ESRD who developed SHPTH and underwent TPTH+AT of parathyroid tissue into the right brachioradialis muscle. Over the course of 7 years he developed a mass at the site of the autotransplanted gland as well as recurrent refractory hyperparathyroidism with increased forearm uptake noted on sestamibi scan. After excision of this mass, pathology demonstrated hyperplasia of the minced gland fragments which were embedded within a mass of fibroadipose tissue rather than the muscle tissue it was originally transplanted in.