Endocrine involvement in systemic amyloidosis.
To present an overview of the published data on endocrine involvement and endocrine dysfunction in patients with systemic amyloidosis. We conducted a review of the medical literature using MEDLINE data sources, including clinical trials, in vitro studies, and case reports on pituitary, thyroid, parathyroid, pancreatic, adrenal, and gonadal involvement in systemic amyloidosis. Reports of endocrine involvement in systemic amyloidosis seem to consist primarily of small-samplesize clinical trials or case reports, probably because of the rarity of the disease itself. Systemic amyloidosis mainly involves and causes functional impairment in the thyroid and testes in the endocrine system. Evaluation of adrenal function necessitates special consideration because amyloid infiltration of the adrenal glands resulting in failure may be a life-threatening condition. Amyloid deposition commonly seen in the pituitary gland and the pancreas of patients with Alzheimer disease and type 2 diabetes mellitus, respectively, is generally classified as local amyloidosis and should not be confused with systemic involvement. Additionally, detection of amyloid deposition in the thyroid and testes may have a diagnostic role in patients with suspected systemic or renal amyloidosis. Published data suggest that systemic amyloidosis frequently involves the endocrine system, and endocrine dysfunction seems to be not as rare as previously thought. A rapidly growing goiter or symptoms and signs of adrenal or gonadal dysfunction should raise suspicion of amyloid infiltration. Involvement of pituitary, parathyroid, and pancreatic sites in systemic amyloidosis still remains to be clarified. Further studies with larger sample sizes are needed for complete characterization of the effect of systemic amyloidosis on the endocrine system.