What are the causes of a suprasellar mass?

Causes of Suprasellar Masses

Suprasellar masses are most commonly caused by pituitary adenomas (84.6%), followed by craniopharyngiomas (3.2%), cystic nonneoplastic lesions (2.8%), inflammatory lesions (1.1%), meningiomas (0.94%), metastases (0.6%), and chordomas (0.5%) 1.

Common Causes of Suprasellar Masses

Neoplastic Causes

• Pituitary Adenomas: Most common cause, can extend superiorly from the sella turcica 2, 1
• Craniopharyngiomas: Typically present as cystic lesions with contrast-enhancing mural nodule(s) 2
• Meningiomas: Common dura-based tumors that can extend into the suprasellar region 2
• Germ Cell Tumors: Particularly common in the suprasellar/hypothalamic region 2
• Metastatic Lesions: From various primary sites including endometrial adenocarcinoma 3
• Schwannomas: Particularly in the cerebellopontine angle 2
• Lymphomas: Rare but can present primarily in the sellar region 1
• Sarcomas: Extremely rare in the sellar region 1
• Leiomyomas and Angioleiomyomas: Rare skull base tumors that can involve the sellar region 2

Non-Neoplastic Causes

• Rathke Cleft Cysts: Common cystic lesions in the sellar/suprasellar region 2
• Empty Sella Syndrome: Herniation of subarachnoid space into the sella turcica, found in up to 30% of patients with hypopituitarism 2, 4
• Inflammatory Processes:
  • Sarcoidosis 2, 1
  • Lymphocytic hypophysitis 2
  • Granulomatous infiltration 2
  • Granulomatosis with polyangiitis 1
• Vascular Lesions:
  • Aneurysms 2
  • Cavernous malformations
• Infectious Processes:
  • Abscesses
  • Tuberculosis
  • Fungal infections

Imaging Characteristics

MRI is the preferred diagnostic imaging modality for evaluation of the sellar and suprasellar regions 2. Key imaging features that help differentiate suprasellar masses include:

• Pituitary Adenomas: Often appear as hypoenhancing lesions on contrast-enhanced MRI 2
• Craniopharyngiomas: Typically present as cystic lesions with contrast-enhancing mural nodule(s) 2
• Meningiomas: Homogeneous enhancement with dural tail sign; superior contour often shows a single upward convex curve 5
• Germ Cell Tumors: Often demonstrate homogeneous enhancement
• Rathke Cleft Cysts: Non-enhancing cystic lesions

Clinical Presentation

The clinical presentation of suprasellar masses depends on their effect on surrounding structures:

• Visual Disturbances: Due to compression of the optic chiasm (e.g., bitemporal hemianopsia) 3
• Endocrine Dysfunction:
  • Hypopituitarism (partial or complete) 2, 4
  • Diabetes insipidus (particularly with lesions affecting the pituitary stalk) 2
  • Hyperprolactinemia (often due to stalk effect)
• Headaches: Common presenting symptom 3
• Cranial Nerve Palsies: Particularly with cavernous sinus invasion 2

Diagnostic Approach

1. MRI with and without contrast is the gold standard for evaluating suprasellar masses 2

   • High-resolution pituitary protocols with thin-section imaging
   • Pre- and post-contrast T1-weighted images
   • T2-weighted and FLAIR sequences

2. CT scanning can provide complementary information 2:

   • Better visualization of calcifications (common in craniopharyngiomas)
   • Assessment of bony involvement or destruction
   • Evaluation of sphenoid sinus for surgical planning

3. Vascular imaging may be necessary in select cases:

   • MR angiography (MRA) or CT angiography (CTA) if vascular lesions are suspected 2

Important Clinical Considerations

• Empty sella syndrome requires comprehensive hormonal evaluation as up to 40% of patients may have at least one hormone deficiency 4
• Pituitary apoplexy (hemorrhage or infarction of a pituitary tumor) requires urgent evaluation and management 2
• For patients with suspected metastatic disease, evaluation for a primary malignancy is essential 3

By understanding the various causes and imaging characteristics of suprasellar masses, clinicians can develop an appropriate differential diagnosis and management plan for patients presenting with these lesions.