Primary hyperaldosteronism is thought to be a relatively common cause of hypertension, possibly accounting for 10% of cases
]. An aldosterone-producing adenoma is an important cause of PA to identify, as surgery would be curative of PA and result in improvement or cure of hypertension and hypokalemia
]. However, there are often difficulties in establishing not only the diagnosis of PA but also the subtype of PA.
Distinguishing unilateral from bilateral aldosterone hypersecretion is done by adrenal venous sampling, a challenging procedure that requires a level of expertise that is not always available
]. In this particular case, AVS gave confusing results, because the cortisol levels should have been much higher in the adrenal veins than was detected, and the aldosterone/cortisol ratio is normally higher in the adrenal vein responsible for the PA than in the periphery. Although, the cortisol-corrected aldosterone ratios in each case showed some level of left lateralization, these data were insufficient to recommend left adrenalectomy. Moreover, these data highlight one of the major challenges in making this diagnosis, since not only is AVS a technically challenging procedure that is operator dependent, but interpretation of the results depends on appropriate specimen dilution by the laboratory
]. Because adrenal macronodules are uncommon in young patients
], and because her 2.3
cm left adrenal mass was new compared with imaging done 1
year prior, she proceeded with laparoscopic left adrenalectomy.
Other forms of primary hyperaldosteronism should always be considered, in particular glucocorticoid-remediable aldosteronism (GRA). In this case, the patient did have a family history of uncontrolled hypertension in her mother. However, further workup for GRA for this patient was not done because she had severe recurrent hypokalemia (less than 2.5
mEq/L), which is typically not seen in GRA
]. Moreover, GRA usually presents at a very early age, often in childhood
]. In addition to GRA, other inherited forms exist, including a recently described family with mutations in the KCNJ5
gene, which leads to massive bilateral adrenal hyperplasia and severe hyperaldosteronism
]. Of importance, somatic mutations of this gene may be an important factor in the development of aldosterone-producing adrenal adenomas
As evident from her initial biochemical studies, this patient clearly had PA. However, initial imaging was negative for adrenal nodules. While small adenomas are not always visible on imaging studies
], AVS often helps localize these lesions. However, three AVS procedures were performed and no precisely defined lateralization was established despite technically successful studies defined as an adrenal vein-to-periphery cortisol ratio of >5:1
]. A lateralization ratio of >4 is commonly used to define a unilateral source of aldosterone overproduction
] and this patient’s lateralization ratio was 2.2. Cases of aldosterone producing adenomas with lateralization ratios <4 have been previously reported
This case raises an important issue for clinicians that our clinical judgment should not be trumped by misleading results (as in this case with data from the AVS procedures and the early imaging studies). While we suspected that this patient had primary hyperaldosteronism based on her symptoms, the data were often hard to interpret. In this case, our persistence ultimately allowed us to make the diagnosis of a unilateral aldosterone-producing adenoma. It is important to follow guidelines, but in certain cases, clinical judgment should not be undervalued.