What is the management approach for a left adrenal myelolipoma?

Management of Left Adrenal Myelolipoma

Adrenal myelolipomas do not require further follow-up imaging or functional testing if they are benign, non-functional, and less than 4 cm in size. 1

Diagnosis and Evaluation

Adrenal myelolipomas are benign neoplasms composed of adipose tissue and myeloid elements. They are relatively uncommon, accounting for approximately 7-15% of adrenal incidentalomas 1.

Initial evaluation should include:

• Imaging characteristics: Myelolipomas typically contain macroscopic fat that can be identified on CT or MRI, making them relatively easy to diagnose radiologically 2
• Size assessment: Measure the exact dimensions of the myelolipoma
• Hormonal evaluation: Despite being typically non-functional, hormonal screening should be performed to rule out subclinical hormone production 2

Management Algorithm

For myelolipomas <4 cm:

• No further follow-up imaging or functional testing is required 1
• These small, asymptomatic myelolipomas can be managed conservatively with observation alone

For myelolipomas ≥4 cm but <7 cm:

• If asymptomatic: Consider repeat imaging in 6-12 months 1
• If symptomatic: Consider surgical removal 3

For myelolipomas ≥7 cm:

• Surgical removal is indicated due to:
  • Risk of spontaneous rupture and hemorrhage 3
  • Difficulty distinguishing from other adrenal malignancies 4
  • Presence of symptoms (typically abdominal pain) 3

For any size myelolipoma:

• Surgical removal is indicated if:
  • Patient is symptomatic (typically abdominal pain) 3
  • Evidence of hormone hypersecretion 2
  • Significant growth (>5 mm/year) on follow-up imaging 1

Surgical Approach

When surgery is indicated:

• Minimally invasive adrenalectomy should be performed when feasible 1, 2
• Open adrenalectomy may be necessary for very large tumors (>10 cm) 2

Follow-up Recommendations

• Myelolipomas that grow <3 mm/year on follow-up imaging require no further imaging or functional testing 1
• If growth is >5 mm/year, adrenalectomy should be considered after repeating functional work-up 1

Important Considerations

• Myelolipomas are invariably benign, but can be confused with other adrenal masses, particularly if they lack the typical fat content 4
• Growth rates are variable - some may grow over time while others remain stable or even decrease in size 5
• The rate of associated endocrine dysfunction may be underestimated; approximately 7.5% of myelolipomas may be associated with adrenal hypersecretory disorders 4
• Congenital adrenal hyperplasia has been associated with about 10% of adrenal myelolipomas 4

Pitfalls to Avoid

• Don't assume all myelolipomas are non-functional; always perform hormonal evaluation 2
• Don't automatically pursue surgery for all myelolipomas; size, symptoms, and growth rate should guide management 4
• Don't confuse myelolipomas with other fat-containing retroperitoneal tumors or adrenal malignancies 2

The management of adrenal myelolipomas has evolved toward a more conservative approach as our understanding of their natural history has improved. Most can be safely observed, with surgery reserved for specific indications based on size, symptoms, and growth patterns.