# Incidentally Discovered Adrenal Mass With Mild Autonomous Cortisol Secretion and Pheochromocytoma

## TL;DR

A rare case of a single adrenal tumor producing both cortisol and catecholamines is described, highlighting the need for thorough testing and careful surgery.

## Contribution

This case report documents a rare collision tumor with both autonomous cortisol secretion and pheochromocytoma features.

## Key findings

- The patient had a collision tumor with features of adrenal cortical adenoma and pheochromocytoma.
- Postoperative normetanephrine levels normalized, and antihypertensive medication needs decreased.
- Comprehensive biochemical and imaging assessment is crucial for managing such rare adrenal tumors.

## Abstract

Adrenal incidentalomas are adrenal masses detected on imaging performed for conditions unrelated to suspected adrenal disease. While pheochromocytomas and adrenal cortical adenomas are well-recognized entities, their coexistence with autonomous cortisol secretion (ACS) within a single lesion is rare and presents diagnostic and therapeutic challenges. A 53-year-old woman was incidentally found to have a left adrenal mass during imaging performed for evaluation of obstructive jaundice. She had hypertension but no classic symptoms of pheochromocytoma or overt Cushing’s syndrome. Adrenal-protocol non-contrast CT showed an attenuation of −13 Hounsfield units (HU), suggestive of a benign adrenal adenoma. Biochemical evaluation revealed non-suppressible cortisol on the overnight dexamethasone suppression test (ONDST) and low-dose dexamethasone suppression test (LDDST), along with suppressed adrenocorticotropic hormone (ACTH), consistent with mild autonomous cortisol secretion (MACS). Additionally, 24-hour urinary fractionated normetanephrine levels were elevated, with normal fractionated metanephrine levels, confirming catecholamine excess. Preoperatively, she was managed with alpha- and beta-blockade, followed by open left adrenalectomy. Intraoperatively, she developed hypertension requiring nitroprusside infusion, and postoperatively she experienced transient hypotension, which was managed with intravenous fluids and hydrocortisone. Histopathology revealed a collision tumor with features of adrenal cortical adenoma and pheochromocytoma. Postoperatively, her requirement for antihypertensive drugs decreased from three to one. Repeat 24-hour urinary fractionated normetanephrine levels were normal at four weeks after surgery. This case highlights the importance of comprehensive biochemical and imaging assessment in adrenal incidentalomas. The tumor’s dual-secretory nature necessitated meticulous perioperative management to prevent complications, and recognition of such rare entities is crucial for optimizing surgical and medical outcomes.