Introduction: When a biochemically active adrenal mass is found, surgery is usually recommended. While partial adrenalectomy is increasing in popularity for small adrenal masses, it is not clear which patients will benefit from adrenal sparing to preserve adrenal function in case of contralateral adrenal pathology. We reviewed the available literature to evaluate the frequency of bilaterality of adrenal involvement with most common primary adrenal tumors and the frequency of other pathologies potentially threatening the health of the adrenal gland.
Methods: We reviewed the available PubMed® literature to evaluate the reported bilaterality of primary adrenal tumors, including hereditary and nonhereditary pheochromocytomas, aldosterone producing adenomas and cortisol producing adenomas, and identified 25 articles describing the frequency of bilaterality of adrenal masses. We also reviewed the literature to assess the etiologies of adrenal damage due to other pathological processes that may affect the adrenal gland in the life span of a patient and calculated the combined probability for adrenal damage.
Results: Bilaterality of adrenal tumors in hereditary and nonhereditary diseases ranged from 4.25% to 80%. Hereditary pheochromocytomas were bilateral in up to 80% of cases while nonhereditary pheochromocytomas were bilateral in up to 25%. Aldosterone producing adenomas were bilateral in about 4% of cases while only case reports reported bilaterality in cortisol producing tumors. Additionally, review of other processes, such as infections, infiltrative etiologies, adrenal metastasis and others accounted for about a 1% chance of adrenal damage from all possible causes.
Conclusions: Partial adrenalectomy may be a valid option for patients with hereditary syndromes as there is an increased likelihood of disease in the contralateral gland. Pheochromocytomas followed by aldosterone producing adenomas appear to have the highest rate of bilateral involvement. Coupled with the possibility that an additional 1% of the population may have adrenals affected by various pathological processes, partial adrenalectomy in patients with metabolically active adrenal tumors should be considered.
Keywords: adrenal gland diseases; adrenal insufficiency; adrenalectomy.