SUN-457 - Adrenal Incidentaloma and Non-Classic Congenital Adrenal Hyperplasia Combine with MACS: A Case Report

A remarkable number of patients with adrenal incidentaloma display Mild Autonomous Cortisol Secretion (MACS). It is also known that researchers have found a high frequency of partial deficiency of 21-alpha-hydroxylase, defined by an exaggerated 17-hydroxyprogesterone (17-OHP) response to ACTH; however, the combination of two or more concomitant alterations is rare, alt-hough described in the literature (1). Some adenomas can produce these precursors (or have intratumoral enzyme defects), making it difficult to distinguish whether hormone abnormalities arise from “pure CAH,” from the adenoma, or from a mixed picture

A 45-year-old male with a history of 46XX SRY-positive karyotype, infertility, secondary hy-pogonadism, and osteopenia presented for evaluation of low testosterone. He was previously diagnosed with a left adrenal incidentaloma measuring 4.4 × 4.1 cm.
A dexamethasone suppression test (DST) showed mild elevation of cortisol (3.7 µg/dL), sup-pressed ACTH (3.6 pg/mL), and elevated 17-hydroxyprogesterone (513.44 ng/dL). Additional laboratory studies included:
• Androstenedione: 0.6 ng/dL (N < 1.6 ng/dL)
• Testosterone: 202 ng/dL
• DHEA-S: 158.6 µg/dL
• 24-hour urine cortisol: 1507 mg/day
• Plasma metanephrines: 61 pg/dL (N 12–67 pg/dL)
• Aldosterone: 6.5 ng/dL (N < 35 ng/dL)
Non-contrast CT of the adrenal glands showed a left adrenal adenoma measuring 4.4 × 4.1 cm which measures 1.4 Hounsfield units.
A 17-hydroxyprogesterone stimulation test showed:
• Baseline: 237.82 ng/dL (N < 138 ng/dL)
• 30 min post-cosyntropin: 3669.70 ng/dL
• 60 min: 3581.79 ng/dL
Based on these results, the patient was diagnosed with NC-CAH and MACS. Due to the indeterminate nature of the adrenal mass and presence of cortisol autonomy, he was evaluated by endocrine surgery and scheduled for adrenalectomy.
CAH due to 21-OHD is characterized by elevations of progesterone, 17-OHP, DHEA-S, androstenedione, and testosterone, accompanied by varying degrees of mineralocorticoid and cortisol deficiencies (2,3). Despite high 17-OHP concentrations, our patient had normal androstenedione, DHEA-S, and aldosterone, but mild cortisol autonomy and low testosterone. Therefore, this case was diagnosed as NC-CAH.
With widespread imaging use, adrenal incidentalomas are detected in approximately 4.5% of the population (2). An elevated 17-OHP level may suggest CAH or an intrinsic effect of an adrenal tumor.
It is important to recognize that elevated 17-OHP (or other precursors) may originate from adenoma steroidogenesis rather than systemic CAH. These observations support the possibility of intratumoral deficits in various steroidogenic enzymes, that is resolved once patients undergo for adrenalectomy.
Our patient underwent for left adrenalectomy. Histopathology was positive for left adrenal adenoma. Currently patient on hydrocortisone replacement therapy due to partial adrenal insufficiency

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