Slowly Growing Adrenal Mass: A 20-Year Incubation

Seventeen years later when she presented with dysuria at the age of 65 years, abdominal CT showed that the left adrenal mass had enlarged to 7.4 cm in diameter (Figure 1C). She declined to have a left adrenalectomy.

The present evaluation was completed at age 68 years—20 years after her initial presentation. She was 153 cm tall and weighed 53.5 kg. Her blood pressure was 101/54 mm Hg. She did not have any signs or symptoms of adrenal cortical hormone excess or deficiency. Her routine laboratory testing was normal. Her plasma ACTH concentration was suppressed, with a normal plasma cortisol concentration at 8 AM. However, her plasma cortisol concentration showed a normal diurnal rhythm and incomplete suppression with the overnight 1-mg DST (Table). An abdominal CT scan demonstrated a 9.7-cm round and inhomogeneously enhanced left adrenal mass with tiny high-density spots (Figure 1D), whereas the right adrenal mass had not changed in size over the 20 years.

Iodine-131-6-iodochoresterol scintigraphy showed normal uptake in the right adrenal mass and absence of uptake in the large left adrenal mass (Figure 2).

On the basis of the clinical, laboratory, and imaging findings, the left adrenal mass was suspected to be an adrenocortical carcinoma. The right adrenal mass was assumed to be an adrenocortical adenoma because it was lipid-rich (according to the low attenuation on CT) and stable in size over 20 years. In view of its benign nature, and to avoid primary adrenal insufficiency, the right adrenal gland was not addressed surgically. The patient agreed to proceed with laparoscopic left adrenalectomy, and an oval encapsulated tumor was removed. Hydrocortisone replacement was discontinued 6 days after the surgery because the patient did not have signs or symptoms of adrenal insufficiency. The plasma ACTH concentration increased to 12.4 pg/mL, and the plasma cortisol and dehydroepiandrosterone sulfate concentrations decreased compared with her preoperative levels. In addition, the plasma cortisol concentration showed normal suppression with the overnight 1-mg DST (Table).

Pathology examination revealed a 9 × 6 × 7-cm oval, smoothly encapsulated, reddish-brown and yellowish tumor. Microscopically the hemorrhagic lesion consisted of hyaline degeneration of stroma, intricately arrayed dilated vessels with fibrin, and old coagulated blood. In addition, at the rim of the hemangioma-like mass there were lipid-rich clear adrenocortical cells, which lacked the long cord structure of normal zona fasciculata (Figure 3). Immunohistochemical staining for steroidogenic enzymes showed that the lipid-rich cells were positive for steroidogenic factor-1, 3β-hydroxysteroid dehydrogenase, and steroid 17-α-hydroxylase/17,20-lyase (Figure 4 A-C), which are key enzymes in the cortisol synthetic pathway. Immunohistochemistry was negative for dehydroepiandrosterone sulfotransferase, cytochrome P450 enzyme steroid 11 β-hydroxylase (CYP11B1), and aldosterone synthase. The zonae fasciculata and reticularis in the normal adjacent adrenal cortex were atrophic, and the immunohistochemical staining was negative for dehydroepiandrosterone sulfotransferase and positive for aldosterone synthase (Figure 4 D-F). These findings suggested that the lipid-rich cells produced cortisol and that the hypothalamic–pituitary–adrenal axis had been chronically suppressed by the adrenal glucocorticoid secretory autonomy. Aldosterone synthesis was preserved. The Weiss score1 was 0/0, and the final diagnosis on pathology was cortisol-producing adrenocortical adenoma with vascular cyst formation.