Normotensive primary aldosteronism in a patient with myasthenia gravis: a localization diagnostic conundrum unraveled by Ga-pentixafor PET/CT - a case report with review of literature.

PURPOSE

While primary aldosteronism (PA) is typically screened in hypertensive patients, normotensive PA remains underrecognized, especially in complex cases where standard diagnostic approaches fail. We present a challenging case of normotensive PA complicated by myasthenia gravis (MG) requiring chronic glucocorticoids, which interfere with conventional cortisol-based adrenal venous sampling (AVS) interpretation. This case highlights the pivotal role of Ga-pentixafor PET/CT as an innovative alternative for subtype differentiation in such complex scenarios.

METHODS

A 30-year-old normotensive woman with MG (on long-term glucocorticoids) was incidentally found to have a left adrenal adenoma. Biochemical testing confirmed PA (elevated ARR, positive captopril challenge test and saline infusion test). Due to glucocorticoid interference with AVS interpretation, Ga-pentixafor PET/CT was utilized for precise localization. We further reviewed literature on alternative diagnostic strategies for PA when conventional cortisol-based AVS interpretation is compromised.

RESULTS

Ga-pentixafor PET/CT successfully localized the aldosterone-producing adenoma, guiding laparoscopic adrenalectomy. Postoperatively, the patient achieved complete biochemical remission (normalized ARR and potassium). To our knowledge, this is the first reported use of Ga-pentixafor PET/CT for PA subtype diagnosis in a glucocorticoid-dependent normotensive patient, offering a paradigm for similar challenging cases.

CONCLUSIONS

For PA patients with confounding factors affecting cortisol-based AVS interpretation (e.g., chronic glucocorticoid use), Ga-pentixafor PET/CT emerges as a robust non-invasive alternative for accurate subtype differentiation. This case provides a novel diagnostic framework for complex PA presentations, advocating for tailored imaging strategies to overcome traditional limitations.

© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.