Endocrine Abstracts

Background

Unilateral forms of primary aldosteronism (PA) are usually surgically treated to remove the source of aldosterone excess. After adrenalectomy, aldosteronism persists in a subset of patients indicating abnormal aldosterone production from the unresected gland.

Objective

To retrospectively analyze histopathology and post-surgical outcomes in a 3-year prospective cohort of patients diagnosed with unilateral PA (2016 to 2018).

Methods

Histopathology was evaluated by the international HISTALDO consensus and postsurgical outcomes were assessed by the PASO criteria.

Results

The cohort comprised 60 adrenals categorized as classical or nonclassical histopathology of unilateral PA. The classical group (solitary aldosterone-producing adenoma or nodule) comprised 45 cases (75% of 60). More than half of these adrenals (26 of 45) displayed aldosterone-producing lesions in the adjacent cortex. The nonclassical group comprised 15 adrenals (25% of 60) characterized by multiple aldosterone-producing micro/nodules or aldosterone-producing diffuse hyperplasia. A high proportion of the classical histopathology group achieved complete biochemical success compared with the nonclassical group (97.6% versus 66.7%, P = 0.002). The ratio of the aldosterone concentration in the contralateral adrenal vein to the peripheral vein was increased in the nonclassical group relative to the classical group (3.8 [1.7–6.5] vs 2.0 [1.1–3.1], P = 0.004).

Conclusion

Adrenals with nonclassical histopathology of unilateral forms of PA are associated with disease persistence and abnormal aldosterone production from the unresected adrenal.