What is the management approach for a patient with a retroperitoneal hematoma and a 15x16 mm left adrenal lesion, without symptoms or precipitating factors?

Management of Retroperitoneal Hematoma with 15x16 mm Left Adrenal Lesion

This asymptomatic patient requires comprehensive hormonal screening followed by repeat imaging in 3-6 months, with the retroperitoneal hematoma managed conservatively if hemodynamically stable, while the small adrenal lesion undergoes standard incidentaloma workup to exclude functional tumors that could have caused spontaneous bleeding. 1, 2

Immediate Assessment of Hemodynamic Status

The first priority is determining hemodynamic stability, as this dictates whether conservative management or urgent intervention is required. 2

• Hemodynamically stable patients with retroperitoneal hematoma should be managed non-operatively with serial clinical examinations and monitoring 2
• Check vital signs for systolic BP <90 mmHg, heart rate >100 bpm, or shock index >1, which would indicate ongoing bleeding requiring intervention 3
• Obtain baseline hematocrit and monitor for decreases >5-6% absolute, which suggests continued bleeding 1
• CT abdomen/pelvis with IV contrast is the gold standard imaging for confirming retroperitoneal hematoma and characterizing the adrenal lesion 1

Critical Hormonal Workup for the Adrenal Lesion

The presence of retroperitoneal hematoma with an adrenal lesion mandates urgent exclusion of pheochromocytoma, as these tumors can cause spontaneous hemorrhage and are potentially life-threatening. 1, 4

Mandatory Screening Tests:

• Screen for pheochromocytoma with plasma or 24-hour urinary metanephrines - this is non-negotiable given the clinical presentation of retroperitoneal bleeding with an adrenal mass 1
• Perform 1 mg overnight dexamethasone suppression test to evaluate for cortisol excess 1
• Check morning plasma aldosterone concentration and plasma renin activity if hypertension is present 1
• If signs of virilization exist, obtain serum androgen testing 1

Pheochromocytoma is a critical diagnosis to exclude because it can present as "silent" pheochromocytoma with spontaneous retroperitoneal hemorrhage, even without classic catecholamine excess symptoms. 4 Other adrenal lesions including adenomas, myelolipomas, and hemangiomas have also been reported as causes of spontaneous retroperitoneal bleeding. 5, 6

Characterization of the Adrenal Lesion

Obtain unenhanced CT to measure Hounsfield units (HU) if not already performed, as this is the key initial test for characterizing adrenal incidentalomas. 1

• Lesions <10 HU on unenhanced CT are consistent with benign lipid-rich adenomas 1
• Lesions >10 HU are indeterminate and require second-line imaging with either washout CT or chemical shift MRI 1
• At 15-16 mm, this lesion is well below the 4 cm threshold that raises concern for malignancy 1

Management Algorithm Based on Imaging and Hormonal Results

If Pheochromocytoma is Confirmed:

• Immediate surgical referral for adrenalectomy after appropriate alpha-blockade 1
• Minimally invasive surgery should be performed when feasible, though retroperitoneal approach allows early control of adrenal vein 7
• Do NOT perform biopsy - this is contraindicated in pheochromocytoma due to risk of hypertensive crisis 1

If Hormonal Screening is Negative and Lesion is Benign (<10 HU):

• No further imaging or hormonal follow-up is required for benign non-functional lesions <4 cm 1
• The retroperitoneal hematoma likely represents spontaneous bleeding from a benign source or minor trauma

If Hormonal Screening is Negative but Lesion is Indeterminate (>10 HU):

• Obtain second-line imaging with washout CT or chemical shift MRI to further characterize 1
• Repeat imaging in 3-6 months to assess for growth 1
• Be aware that approximately one-third of pheochromocytomas can show washout patterns similar to adenomas, and one-third of adenomas may not washout typically 1

If Mild Autonomous Cortisol Secretion (MACS) is Detected:

• Annual clinical screening for metabolic comorbidities (diabetes, hypertension, osteoporosis) is recommended 1
• Adrenalectomy may be considered in younger patients with progressive metabolic complications after shared decision-making 1

Conservative Management of Retroperitoneal Hematoma

More than 80% of retroperitoneal hematomas can be treated conservatively with transfusions without surgery if the patient remains hemodynamically stable. 1

• Monitor for signs of expansion: hypotension, suprainguinal tenderness, severe back or lower-quadrant abdominal pain 1
• Serial hematocrit measurements to detect ongoing bleeding 1
• Angiography with super-selective angioembolization is indicated if arterial contrast extravasation or pseudoaneurysm is identified on CT in a stable patient 2

Critical Pitfalls to Avoid

• Never biopsy an adrenal lesion before excluding pheochromocytoma - this can precipitate hypertensive crisis 1
• Do not assume the hematoma is traumatic without hormonal workup - functional adrenal tumors are well-documented causes of spontaneous retroperitoneal hemorrhage 4, 5, 6
• Beware that approximately one-third of pheochromocytomas may appear benign on washout CT, so clinical suspicion and hormonal testing take precedence 1
• In hemodynamically unstable patients, immediate operative management takes priority over complete workup 2, 8

Follow-Up Strategy

• If initial hormonal workup and imaging suggest benign adenoma (<10 HU, <4 cm, non-functional): no further adrenal-specific follow-up is needed 1
• If indeterminate lesion: repeat imaging at 3-6 months, then annually if stable 1
• Resolution of retroperitoneal hematoma should be confirmed on follow-up imaging
• Any growth >5 mm/year warrants repeat hormonal workup and consideration of adrenalectomy 1