What is the recommended treatment for a patient with a small subcortical cyst in the lateral humeral head and a history of a fall a few months ago, with no post-traumatic bony changes demonstrated?

Management of Small Subcortical Cyst in the Lateral Humeral Head

Conservative management with observation and routine follow-up is recommended for an asymptomatic small subcortical cyst in the lateral humeral head with no post-traumatic bony changes.

Clinical Assessment and Diagnosis

The radiographic findings in this case reveal:

• Small subcortical cyst within the lateral humeral head
• No post-traumatic bony changes
• Intact bones
• Maintained acromioclavicular and coracoclavicular distances
• No heterotopic ossifications
• Maintained glenohumeral joint spacing

These findings are consistent with an incidental subcortical cyst, which is a common finding that often represents a normal variant rather than pathology requiring intervention 1.

Management Approach

Recommended First-Line Management

1. Observation with clinical follow-up

   • Monitor for changes in symptoms
   • No immediate intervention required for asymptomatic cysts
   • Reassurance that this is likely a benign finding

2. Pain management if symptomatic

   • NSAIDs for mild discomfort
   • Activity modification during symptomatic periods

Imaging Follow-up

• Follow-up radiographs in 6-12 months if the patient becomes symptomatic
• MRI without contrast is appropriate if symptoms develop or worsen 2
  • MRI is the most sensitive imaging modality for evaluating bone lesions and associated soft tissue abnormalities
  • Helps differentiate between simple cysts and other pathologies

Differential Diagnosis

1. Normal anatomic variant

   • Small cysts in the posterosuperior portion of the humeral head are often normal variants 1
   • These pseudocysts may be connected to joint spaces and lined with collagen connective tissue

2. Intraosseous ganglion cyst

   • Usually asymptomatic but can cause pain with activity 3
   • May mimic impingement syndrome or labral tear

3. Unicameral bone cyst

   • Simple fluid-filled lesion
   • Typically asymptomatic unless pathologic fracture occurs 4

4. Early avascular necrosis

   • Would typically show additional MRI findings
   • Usually presents with more significant pain 5

When to Consider Intervention

Surgical intervention is only indicated if:

1. The patient develops significant pain that correlates with the cyst location
2. The cyst enlarges significantly on follow-up imaging
3. Risk of pathologic fracture increases (cyst size >2/3 of bone diameter)
4. Functional limitations develop that are directly attributable to the cyst

Surgical Options (if needed in the future)

If intervention becomes necessary due to symptoms or progression:

1. Arthroscopic curettage and bone grafting

   • Less invasive approach with shorter recovery time 4
   • Appropriate for symptomatic cysts with good bone integrity

2. Injection therapies

   • Steroid injection, demineralized bone matrix, or bone marrow aspirate
   • Less invasive than open procedures 6

Key Points for Patient Education

• Small subcortical cysts are common incidental findings
• The absence of post-traumatic changes suggests this is unrelated to the fall
• Most remain asymptomatic and require no treatment
• Follow-up is recommended if symptoms develop or worsen
• Prognosis is excellent with conservative management

Pitfalls and Caveats

• Avoid unnecessary invasive procedures for asymptomatic cysts
• Don't attribute unrelated shoulder pain to the cyst without clear correlation
• Be aware that radiographs alone may not fully characterize the lesion if symptoms develop
• Distinguish between this incidental finding and the patient's fall history, which appears unrelated based on the absence of post-traumatic changes

The ACR Appropriateness Criteria supports using MRI without contrast as the next appropriate imaging study if the patient becomes symptomatic, as it provides the most comprehensive evaluation of bone and soft tissue abnormalities 2.