A Borderline Adrenal Incidentaloma: How Much Surveillance Does a Negative Workup Still Need
A single patient whose entirely negative hormonal workup meets an adrenal mass that doesn't cleanly satisfy the newest guideline's own criteria for stopping imaging follow-up altogether.
Trevor N., a 55-year-old high school shop teacher, found out about his adrenal nodule the same way most people do — an unrelated CT, this one for suspected appendicitis that turned out to be a resolving diverticulitis instead. He has spent the weeks since reading everything he can find online about adrenal masses, a habit his wife has gently asked him to stop, and arrives at today's visit with a printed list of questions. The 2.4 cm right adrenal mass measured 14 Hounsfield units on the non-contrast images, mostly homogeneous but with a small area of subtle heterogeneity the radiologist flagged without calling outright concerning. A full hormonal workup — 1 mg dexamethasone suppression, plasma metanephrines, and, given his hypertension, an aldosterone-renin ratio — came back entirely normal. The nodule, in other words, is almost certainly benign and entirely nonfunctioning. The disagreement in front of the team isn't about what it is; it's about what, if anything, happens next.
Practice on this question has genuinely moved. Older guidance, still followed at some centers, called for repeat imaging at six to twelve months and then annually for a defined period, treating any incidentaloma as worth watching regardless of its initial imaging characteristics. The 2023 European Society of Endocrinology guideline instead states that a homogeneous adrenal mass with an attenuation of 10 Hounsfield units or below needs no further imaging follow-up at all, irrespective of size — a real, recent de-escalation from the older standard. Trevor's mass sits just above that clean 10-HU cutoff, with the added complication of the subtle heterogeneity the radiologist noted, so neither the new guideline's clearest "stop" language nor the old schedule's blanket "watch it" applies to him without some interpretation either way.
Endocrinology consult, reviewing the imaging and labs
Every functional test came back negative, and the 2023 ESE guideline no longer recommends routine follow-up imaging for a definitively benign-appearing mass regardless of size. I'd tell him this chapter is closed rather than schedule a repeat scan that carries its own radiation and cost for a finding that's already reassuring on every axis we can test.
I'd slow down on treating this as the clean case the newest guideline had in mind. I specifically noted the heterogeneity in my read — not as a throwaway line, but because it's genuinely there, and his attenuation sits just above the clean 10-HU threshold the guideline actually uses to justify stopping imaging entirely. One repeat scan at six to twelve months, watching for stability, is a reasonable middle ground I wouldn't want skipped just because the functional labs are clean.
I'm not proposing the old annual-surveillance schedule indefinitely — just one confirmatory look, given what I actually saw on the images, not what a size-and-density rule alone would predict.
Then let's actually ask what "heterogeneity noted, not called concerning" means in practice before either of you commits to a plan built on how that phrase gets read. I'll set up a direct conversation between endocrinology and radiology about this specific image, not a hypothetical one — and whatever they agree the finding actually supports is what I'll tell Trevor, rather than us choosing between two guideline eras without that clarification.
Agreed: hold any imaging decision until endocrinology and radiology jointly review the specific images and clarify what the noted heterogeneity actually supports, rather than defaulting to either guideline era without that step.
Not agreed: what should happen if that review remains genuinely ambiguous rather than resolving cleanly either way. The radiologist would default to the single confirmatory scan in that case; the endocrinologist would rather trust the negative functional workup and stop there even with residual imaging uncertainty, reasoning that hormonal testing is the more decision-relevant axis for this patient regardless of subtle imaging texture.