What are the characteristics of a pituitary (hypophyseal) sellar meningioma?

From the Guidelines

Pituitary sellar meningioma diagnosis and treatment should prioritize MRI imaging for evaluation and monitoring, given its high sensitivity and specificity in characterizing lesions in the sellar and parasellar regions 1.

Diagnosis and Imaging

• MRI using high-resolution pituitary protocols is the preferred diagnostic imaging modality for evaluation of the pituitary and sellar regions, as it reliably depicts anatomy and pathologies involving the pituitary gland, infundibulum, optic chiasm, and vascular structures 1.
• The addition of IV contrast increases the conspicuity of small adenomas and is useful for characterizing lesions, but MRI with IV contrast may only be performed for use in operative guidance and should not be considered a first-line imaging test 1.
• MRI can confirm absence or ectopia of the posterior pituitary gland and suggest pituitary underdevelopment, although objective criteria for pituitary hypoplasia do not exist 1.

Treatment and Management

• Treatment typically involves surgical removal, with the transsphenoidal approach being preferred for smaller tumors, while craniotomy may be necessary for larger tumors 1.
• Complete resection is the goal when possible and safe, and radiation therapy may be recommended for residual tumor tissue, recurrence, or cases where surgery is contraindicated.
• Symptoms often result from compression of nearby structures and may include headaches, visual disturbances, hormonal imbalances, and rarely, cerebrospinal fluid leakage.

Follow-up and Monitoring

• Regular follow-up with MRI imaging is essential after treatment to monitor for recurrence, typically every 6-12 months initially, then annually 1.
• These tumors grow slowly and have a good prognosis with appropriate treatment, with many patients achieving long-term tumor control.
• Unlike pituitary adenomas, sellar meningiomas originate from different tissue and typically don't cause hormonal overproduction, though they may cause hormonal deficiencies through compression of the normal pituitary gland.

From the Research

Pituitary Sellar Meningioma

• Pituitary sellar meningiomas are rare tumors that account for about 1% of sellar masses 2
• They can mimic pituitary adenomas but are more vascularized and invasive 2
• The most common symptoms of pituitary sellar meningiomas are visual disturbances, headache, and incidental findings 2
• Hyperprolactinemia is found in approximately 36% of patients with pituitary sellar meningiomas 2

Clinical Characteristics

• The majority of patients with pituitary sellar meningiomas are female, with a female-to-male ratio of 6:1 2
• The mean age of patients with pituitary sellar meningiomas is 52 years, with a range of 30-78 years 2
• The mean maximal diameter of pituitary sellar meningiomas is 2.9 cm, with a range of 0.9-6.8 cm 2
• A "dural tail" sign is reported in approximately one-third of cases 2

Treatment and Outcomes

• Surgical cure is achieved in approximately 53% of patients with pituitary sellar meningiomas after initial surgery 3
• Postsurgical hypopituitarism occurs with high frequency, and many patients require subsequent surgical intervention or adjunctive treatment with external beam radiation 3
• Gross total resection (GTR) is achieved in approximately 34% of operated patients, whereas in 65% of cases, the tumor is incompletely removed 4
• After treatments, hypopituitarism is present in approximately 53% of patients at the last evaluation, and it is associated with surgery extension (subtotal or GTR) but not with tumor subtype, type of radiotherapy, or radiation dose received 4

Surgical Approaches

• The endonasal microscopic approach is a minimally invasive route for removal of pituitary adenomas and other parasellar tumors, including pituitary sellar meningiomas 5
• The endoscopic endonasal transsphenoidal approach is a slightly modified technique that has been successfully used in patients with pituitary lesions, including pituitary sellar meningiomas 6
• The advantages and limitations of these techniques are discussed and compared to standard transsphenoidal surgery 5, 6