What are the implications and necessary follow-up steps for a partially empty sella (sella turcica) found on a head Computed Tomography (CT) scan?

Management of Partially Empty Sella Found on Head CT Scan

A partially empty sella found incidentally on a head CT scan requires endocrine evaluation, as up to 30% of patients may have hypopituitarism requiring treatment. 1, 2

Diagnostic Approach

Imaging Follow-up

• MRI with high-resolution pituitary protocols is the gold standard for further evaluation 2
  • Superior to CT for characterizing empty sella even without IV contrast
  • Can show flattened pituitary gland against sellar floor and CSF-filled sella turcica
  • Can detect small adenomas that CT might miss

Clinical Evaluation

• Comprehensive hormonal assessment is mandatory, regardless of symptoms 2, 3

  • Morning cortisol and ACTH (secondary adrenal insufficiency occurs in higher rates with complete empty sella) 3
  • TSH and free T4 (secondary hypothyroidism)
  • FSH, LH, estradiol (females) or testosterone (males) for gonadal function
  • Prolactin levels
  • Growth hormone and IGF-1

• Ophthalmologic examination 2

  • Visual field testing to rule out compression of visual pathways
  • Assessment for papilledema (may indicate increased intracranial pressure)

Classification and Clinical Significance

Primary vs. Secondary Empty Sella

• Primary empty sella: Spontaneous herniation of subarachnoid space into sella turcica 4

  • May be associated with idiopathic intracranial hypertension
  • Often an incidental finding without clinical implications

• Secondary empty sella: Results from previous pituitary pathology 4

  • Prior surgery, radiation therapy, or medical treatment
  • Pituitary apoplexy or necrosis
  • Infectious or autoimmune processes

Partial vs. Complete Empty Sella

• Partial empty sella: <50% CSF filling, pituitary >2mm thick 3

  • Lower but still significant risk of hormonal abnormalities

• Complete empty sella: ≥50% CSF filling, pituitary <2mm thick 3

  • Higher risk of secondary adrenal insufficiency and hypogonadism
  • More likely to have multiple affected hormonal axes

Management Recommendations

For All Patients with Partially Empty Sella

1. Refer to endocrinology for comprehensive hormonal evaluation 2, 3
2. Initiate hormone replacement therapy based on specific deficiencies 2
   • Levothyroxine for hypothyroidism
   • Hydrocortisone for adrenal insufficiency (15-25 mg daily in divided doses)
   • Sex hormone replacement for hypogonadism
   • Growth hormone if deficient

Special Considerations

• If adrenal insufficiency is diagnosed:

  • Patient should obtain a medical alert bracelet 2
  • Start steroid replacement BEFORE thyroid replacement if both are needed 2

• If headaches or visual disturbances are present:

  • Evaluate for increased intracranial pressure 5
  • Consider ophthalmology consultation 2

Prognosis

• Most patients with partial empty sella have good prognosis and remain asymptomatic 2
• Regular endocrine follow-up is necessary, especially for those with hormonal deficiencies
• Surgical intervention is rarely needed for partial empty sella unless CSF rhinorrhea develops 6

Common Pitfalls to Avoid

1. Assuming empty sella is always benign - up to 30% have hypopituitarism requiring treatment 1, 2
2. Relying on CT alone - MRI is superior for pituitary imaging 1, 2
3. Missing secondary causes - evaluate for history of pituitary disease, surgery, or radiation 4
4. Overlooking increased intracranial pressure - empty sella can be associated with idiopathic intracranial hypertension 5
5. Initiating thyroid replacement before steroid replacement - can precipitate adrenal crisis in patients with both deficiencies 2