MANAGEMENT OF ENDOCRINE DISEASE: Differential diagnosis, investigation and therapy of bilateral adrenal incidentalomas

Abstract

The investigation and management of unilateral adrenal incidentalomas have been extensively considered in the last decades. While bilateral adrenal incidentalomas represent about 15% of adrenal incidentalomas (AIs), they have been less frequently discussed. The differential diagnosis of bilateral incidentalomas includes metastasis, primary bilateral macronodular adrenal hyperplasia and bilateral cortical adenomas. Less frequent etiologies are bilateral pheochromocytomas, congenital adrenal hyperplasia (CAH), Cushing's disease or ectopic ACTH secretion with secondary bilateral adrenal hyperplasia, primary malignancies, myelolipomas, infections or hemorrhage. The investigation of bilateral incidentalomas includes the same hormonal evaluation to exclude excess hormone secretion as recommended in unilateral AI, but diagnosis of CAH and adrenal insufficiency should also be excluded. This review is focused on the differential diagnosis, investigation and treatment of bilateral AIs.

Adrenal Incidentaloma

“…On unenhanced CT, both adrenal glands are enlarged usually with multiple nodules but diffuse enlargement without nodules is also seen ( 325 ). On contrast-enhanced imaging, nodules can have marked enhancement, and HU >10 has also been described.…”

“…Bilateral adrenalectomy is recommended for bilateral pheochromocytomas; however, the risk of adrenal insufficiency and the side effects of life long glucocorticoid replacement have led to certain centers performing adrenal cortex sparing resections particularly in the setting of genetic syndromes such as VHL and MEN2A where the risk of malignant tumors is low ( 325 ).…”

Neoplastic metastases to the endocrine glands

“…The frequencies of adrenal metastases at autopsy, adrenalectomy and fine-needle aspiration (FNA) biopsies were 3.1, 7.5 and 33%, respectively (Lam & Lo 2002) (Table 1). Although synchronous bilateral metastases are rare (<0.5%) (Ozturk 2015, Shumarova 2016, occurring mostly with melanoma, thyroid, sarcomatoid, hepatocellular, bladder and in 4% of patients with non-small-cell lung cancer (NSCLC) (Tanvetyanon et al 2008), the prevalence of bilateral adrenal metastases in lymphomas reaches 71% (Peters et al 2013, Bourdeau et al 2018. Approximately 50% of melanomas, 30-40% of breast and lung, and 10-20% of renal and gastrointestinal cancers, metastasise to the adrenals in surgical series (Lam & Lo 2002, Wansaicheong & Goh 2016.…”

WFUMB position paper on the management incidental findings: adrenal incidentaloma

“…In patients with a high body mass index, diabetes mellitus, and arterial hypertension, the prevalence is even higher [15,16]. Bilateral AIs are found in about 10%-15% of cases [17-19]. In unselected healthy subjects and in patients with inflammatory bowel disease, a prevalence of 5% was reported using abdominal US [8,20-22].…”

“…Patients with bilateral AI should be investigated for Cushing's disease, congenital adrenal hyperplasia, and BMAH [19,96]. The indication for surgery in bilateral NFAI is more restricted.…”