Attenuation Value in Adrenal Incidentalomas: A Longitudinal Study

ContextA tendency to grow has been reported in adrenal incidentalomas. However, long-term data regarding attenuation value, a measure of lipid content, are not available.AimThis study aims to collect radiological data (diameter in mm and attenuation value in Hounsfield units, HU) with computed tomography (CT) in adrenal incidentalomas, in order to compare baseline characteristics with the last follow-up imaging.DesignThis is a longitudinal study which included patients with a new diagnosis of adrenal incidentaloma, evaluated from January 2002 to June 2020.SettingReferral University-Hospital center.PatientsTwo hundred seventy-seven patients with 355 different cortical adenomas (baseline group) were evaluated at the first outpatient visit; the follow-up cohort consists of 181 patients with 234 adenomas (12–175 months after baseline). Inclusion criteria were conservative management and radiological features able to minimize malignancy or risk of progression.Main Outcome MeasureCT modification according to endocrine function: autonomous cortisol secretion (ACS) if cortisol >50 nmol/L after 1-mg dexamethasone test (DST).ResultsAt baseline CT, mean diameter was 18.7 mm and attenuation value was 0.8 HU (higher in ACS, 66 cases >10 HU), without modification in early imaging (12–36 months). The size increased over time (r = 0.289), achieving the largest differences after at least 60 months of follow-up (mean diameter, +2 mm; attenuation value, −4 HU), combined with a reduction in the attenuation value (r = −0.195, especially in patients with ACS). Lipid-poor adenomas (>10 HU) presented a reduced cortisol suppression after 1-mg DST, an increase in size and the largest decrease in attenuation value during follow-up. Univariate analysis confirmed that larger adenomas presented reduced suppression after DST and increase in size during follow-up.ConclusionsGrowth is clinically modest in adrenal incidentaloma: the first follow-up CT 5 years after baseline is a reasonable choice, especially in ACS. Mean density is increased in patients with ACS and overt hypercortisolism. Mean density reduces during follow-up in all adrenal adenomas, suggesting an increase in lipid content, especially in those with ACS.

Predictors of Tumour Growth and Autonomous Cortisol Secretion Development during Follow-Up in Non-Functioning Adrenal Incidentalomas

Purpose: To assess the risk of developing autonomous cortisol secretion (ACS) and tumour growth in non-functioning adrenal incidentalomas (NFAIs). Methods: Multicentre retrospective observational study of patients with NFAIs. ACS was defined as serum cortisol >1.8 µg/dL after 1 mg-dexamethasone suppression test (DST) without specific data on Cushing’s syndrome. Tumour growth was defined as an increase in maximum tumour diameter >20% from baseline; and of at least 5 mm. Results: Of 654 subjects with NFAIs included in the study, both tumour diameter and DST were re-evaluated during a follow-up longer than 12 months in 305 patients. After a median follow-up of 41.3 (IQR 24.7–63.1) months, 10.5% of NFAIs developed ACS. The risk for developing ACS was higher in patients with higher serum cortisol post-DST levels (HR 6.45 for each µg/dL, p = 0.001) at diagnosis. Significant tumour growth was observed in 5.2% of cases. The risk of tumour growth was higher in females (HR 10.7, p = 0.004). Conclusions: The frequency of re-evaluation with DST in NFAIs during the initial 5 years from diagnosis can probably be tailored to the serum cortisol post-DST level at presentation. Re-evaluation of NFAIs with imaging studies, on the other hand, seems unnecessary in most cases, particularly if the initial imaging demonstrates features specific to typical adenoma, given the low rate of significant tumour growth.

SP5.2.6 Adrenal Incidentalomas in Living Kidney Donors: A Dilemma?

Aims During donor multi-detector CT angiogram (MDCTA), incidental findings occur, commonly adrenal incidentalomas (AIs). These are usually benign and non-functional with an estimated incidence of 4%.1 These potentially limit organ donation due to the need to exclude malignancy. There is no consensus on the management of donors with AIs.1,2 This study aims to explore the incidence and clinical course of AI’s in living kidney donors. Methods We performed a single-centre, retrospective study on all prospective living kidney donors between November 2000 and September 2020. Patients with adrenal lesions during work-up were identified and further information was collected from electronic patient records. Results Six (1.09%) of the 546 donors during that period had an AI. All were small (<4cm) and non-functional with benign radiographic features. Five (83.3%) proceeded to donation while 1 (16.7%) was unsuitable for donation due to complex vascular anatomy. Of the five donors that proceeded, 2 (40%) were contralateral and 3 (60%) ipsilateral AI’s to the side of nephrectomy. Of the 3 ipsilateral AIs, 2 (66.7%) underwent nephrectomy alone whilst 1 (33.3%) underwent a simultaneous nephrectomy and adrenalectomy. There was no evidence of malignancy or functional change in AIs post-donation. Conclusion The incidence of adrenal pathology in living donors is low and largely benign. These patients should not be excluded from donation. Such patients could benefit from open discussion regarding simultaneous adrenalectomy vs conservative management.