What is the initial approach to diagnose and treat unilateral adrenalitis in an inpatient?

Diagnostic and Management Approach to Unilateral Adrenalitis in the Inpatient Setting

The initial approach to unilateral adrenalitis requires comprehensive imaging with non-contrast CT followed by hormonal evaluation to determine functionality, with management decisions based on imaging characteristics and hormone status. 1

Initial Diagnostic Workup

Imaging Studies

1. Non-contrast CT scan as first-line imaging 1

   • Evaluate for:
     • Hounsfield units (HU) measurement (<10 HU suggests benign lesion)
     • Size (>4 cm raises concern for malignancy)
     • Margins (irregular margins suggest malignancy)
     • Heterogeneity

2. Second-line imaging if initial CT is indeterminate 1

   • Contrast-enhanced CT with washout protocol
   • Chemical-shift MRI

Hormonal Evaluation

All patients with unilateral adrenal lesions should undergo:

1. Cortisol evaluation 1

   • 1 mg overnight dexamethasone suppression test
   • Morning cortisol level

2. Aldosterone evaluation (if hypertension or hypokalemia present) 1

   • Plasma aldosterone-to-renin ratio
   • Confirmatory testing with saline suppression if ratio >30

3. Catecholamine evaluation (if HU >10 or symptoms present) 1

   • 24-hour urinary metanephrines or plasma metanephrines

4. Androgen testing (if virilization present or malignancy suspected) 1

   • Serum DHEA-S, testosterone, androstenedione

Management Algorithm Based on Findings

For Functional Adrenal Lesions:

1. Cortisol-secreting adenomas 1

   • Unilateral laparoscopic adrenalectomy for overt Cushing's syndrome
   • Consider adrenalectomy for mild autonomous cortisol secretion in younger patients with metabolic comorbidities

2. Aldosterone-secreting adenomas 1

   • Confirm lateralization with adrenal vein sampling
   • Laparoscopic adrenalectomy if unilateral source confirmed
   • Medical management with mineralocorticoid receptor antagonists if surgery not possible

3. Pheochromocytoma 1

   • Preoperative alpha-blockade followed by beta-blockade
   • Laparoscopic adrenalectomy

For Non-functional Adrenal Lesions:

1. Benign-appearing lesions <4 cm with <10 HU 1

   • No further follow-up required

2. Benign-appearing lesions ≥4 cm with <10 HU 1

   • Repeat imaging in 6-12 months
   • No further follow-up if growth <3 mm/year
   • Consider adrenalectomy if growth >5 mm/year

3. Indeterminate lesions 1

   • Options include:
     • Repeat imaging in 3-6 months
     • Surgical resection
   • Decision based on patient factors and clinical suspicion

4. Lesions with features concerning for malignancy 1

   • Size >4-6 cm
   • Irregular margins
   • Heterogeneous appearance
   • Rapid growth
   • Recommend surgical resection

Special Considerations for Unilateral Adrenalitis

Infectious Causes

• Consider tuberculosis, histoplasmosis, or cryptococcosis 2
• Obtain appropriate cultures and consider adrenal biopsy if suspected

Autoimmune Adrenalitis

• Usually bilateral but can present unilaterally in early stages 3
• Check adrenal autoantibodies if suspected

Metastatic Disease

• Consider PET scan if history of malignancy 1
• Adrenal biopsy may be indicated in select cases 1

Pitfalls to Avoid

1. Misdiagnosing adrenal insufficiency

   • Unilateral adrenalitis rarely causes adrenal insufficiency unless the contralateral gland is compromised 4
   • Monitor for symptoms of insufficiency if bilateral involvement is suspected

2. Inappropriate adrenal biopsy

   • Adrenal biopsy should not be performed routinely 1
   • Consider only when:
     • Infectious etiology is suspected
     • Metastatic disease is suspected and would change management
     • Other diagnostic methods have failed

3. Missing concomitant conditions

   • In autoimmune adrenalitis, up to 50% develop other autoimmune disorders 4
   • Screen for associated conditions if autoimmune etiology is suspected

4. Inadequate preoperative preparation

   • Functional tumors require specific preoperative management
   • Pheochromocytomas require alpha-blockade before beta-blockade
   • Cortisol-producing tumors may require perioperative steroid coverage

By following this systematic approach to diagnosis and management of unilateral adrenalitis, clinicians can ensure appropriate treatment while minimizing unnecessary procedures and optimizing patient outcomes.