Question: How common are bilateral adrenal adenomas? Is there a way to tell if the adenomas on both glands are functional? Could this actually be bilateral adrenal hyperplasia?

Answer: Almost certainly bilateral adenomas are a form of hyperplasia, which I have called type-I macronodular hyperplasia.

1. I suppose there could be the individual patient where this may not be the case, but if the patient has Cushing’s syndrome, this has to be considered and the patient has to be tested for ARMC5 mutations.
2. Additional investigations may be used like PET scanning
3. to try to determine the bilateral or unilateral nature of the disease. Adrenal venous sampling has been well validated in primary hyperaldosteronism only. Some reports mention its use in adrenal Cushing’s but this is has not been well studied or validated.

By Dr. Constinine Stratakis, NIH, Bethesda, MD with other members of the NIH team, Spring, 2016

References

1. Hsiao, et al, Clinical and Genetic Heterogeneity, Overlap with Other Tumor Syndromes, and Atypical Glucocorticoid Hormone Secretion in Adrenocorticotropin Independent Macronodular Adrenal Hyperplasia Compared with Other Adrenocortical Tumors. J Clin Endocrinol Metab, August 2009, 94(8):2930 –2937
2. Faucz, et al, Macronodular Adrenal Hyperplasia due to Mutations in an Armadillo Repeat Containing 5 (ARMC5) Gene: A Clinical and Genetic Investigation. J Clin Endocrinol Metab, June 2014, 99(6):E1113–E1119
3. Patel, et al, FDG PET/CT Scan and Functional Adrenal Tumors: A Pilot Study for Lateralization. World J Surg. 2016 Mar;40(3):683-9. doi: 10.1007/s00268-015-3242-y.