Isolated adrenal metastasis from breast cancer: adrenalectomy and exemestane plus palbociclib

What happened, in summary

A 69-year-old woman had a remote history of invasive ductal breast carcinoma treated with lumpectomy and chemotherapy, followed by 15 years in remission. She also had papillary thyroid carcinoma treated with thyroidectomy 10 years earlier. She later developed 4 years of intermittent right-sided abdominal pain. CT imaging found 2 right adrenal nodules that were not present on imaging 2 years before. Hormonal testing was normal, ruling out common functioning adrenal tumors such as Cushing syndrome, pheochromocytoma, and primary hyperaldosteronism. PET imaging showed no hypermetabolic activity, but the adrenal nodules remained indeterminate and continued to enlarge during surveillance. After review by an adrenal tumor board, she initially chose monitoring with CT scans every 6 months. When repeat imaging showed further growth, she proceeded with laparoscopic right adrenalectomy. Pathology unexpectedly showed metastatic carcinoma of breast origin. The tumor was ER-positive, PR-positive, and HER2-negative, with breast-lineage markers including GATA3 and mammaglobin. Follow-up CT abdomen/pelvis and PET-CT showed no evidence of metastatic disease elsewhere, suggesting an isolated adrenal metastasis. She then started exemestane and palbociclib, combining endocrine therapy with CDK4/6-targeted therapy. Surveillance included CT abdomen/pelvis every 6 months, annual mammography, and annual PET imaging. As of July 2025, surveillance had shown no recurrence so far while she remained on treatment. The adrenal workup was clinically important because the nodules looked lipid-poor and indeterminate on CT, yet did not show PET uptake or hormone production. Surgery was chosen only after interval growth made continued surveillance less reassuring, and pathology then established the breast-cancer origin.