Preoperative Workup for 12 mm Adrenal Nodule Before Cataract Surgery
A 12 mm adrenal nodule requires initial hormonal evaluation but does not require further imaging workup or delay of cataract surgery if the nodule is non-functional and has benign imaging characteristics. 1
Initial Assessment Required
The adrenal nodule must undergo a one-time hormonal evaluation regardless of its benign appearance, as approximately 5% of radiologically benign incidentalomas have subclinical hormone production that requires treatment before any surgery. 2 This evaluation includes:
- 1 mg overnight dexamethasone suppression test to screen for autonomous cortisol secretion (applying a cutoff of serum cortisol ≤50 nmol/L or ≤1.8 µg/dL) 1, 3
- Plasma or 24-hour urinary metanephrines to exclude pheochromocytoma, particularly if the nodule measures >10 Hounsfield Units (HU) on non-contrast CT or if there are any signs of catecholamine excess 1, 4
- Aldosterone-to-renin ratio only if the patient has hypertension and/or hypokalemia 1
Imaging Characterization
If not already performed, obtain non-contrast CT to measure Hounsfield units. 1, 3 A 12 mm nodule with HU ≤10 on unenhanced CT is definitively benign and requires no further imaging. 3 If HU >10, second-line imaging with washout CT or chemical-shift MRI should be performed to confirm benign characteristics. 1, 2
Decision Algorithm for Cataract Surgery
If the nodule is non-functional and benign-appearing (HU <10):
- Proceed with cataract surgery without delay 1, 2
- No further follow-up imaging or functional testing is required for this small benign nodule 1, 2
If autonomous cortisol secretion is detected (cortisol post-dexamethasone >50 nmol/L):
- The patient requires perioperative glucocorticoid stress-dose coverage for the cataract surgery 4, 5
- Administer hydrocortisone 100 mg IV before surgery, then every 8 hours, with gradual taper postoperatively 5
If pheochromocytoma is detected:
- Cataract surgery must be delayed until the pheochromocytoma is surgically removed 1, 4
- Preoperative alpha-blockade with phenoxybenzamine or doxazosin is mandatory before pheochromocytoma resection 5
- Any surgery without addressing a pheochromocytoma first risks intraoperative hypertensive crisis 6, 5
Critical Pitfalls to Avoid
Do not skip the initial hormonal evaluation even though the nodule is small and likely benign, as undiagnosed pheochromocytoma can cause life-threatening hypertensive crisis during any surgical procedure, including cataract surgery. 1, 6
Do not perform adrenal biopsy as part of this workup, as it is not indicated for adrenal incidentalomas and carries unnecessary risks. 1
Do not delay cataract surgery for additional adrenal imaging if the nodule is <40 mm, non-functional, and has benign imaging characteristics (HU <10), as these nodules require no further follow-up. 1, 2