What is the management approach for a child presenting with a sellar mass?

Management of Sellar Masses in Children

A child presenting with a sellar mass requires immediate MRI with high-resolution pituitary protocols, comprehensive endocrine evaluation, and ophthalmologic assessment, followed by multidisciplinary treatment planning that prioritizes surgical resection for most lesions except prolactinomas. 1, 2

Initial Diagnostic Workup

Imaging Protocol

• MRI with high-resolution pituitary protocols is the gold standard for evaluating pediatric sellar masses, providing superior tissue characterization compared to CT 1
• Obtain thin-section imaging (≤0.5 cm slice thickness) with pre- and post-contrast T1-weighted sequences to define tumor extent and relationship to critical structures 1
• MRI can directly visualize the pituitary gland and characterize lesions even without IV contrast, though contrast increases conspicuity of small adenomas 1
• CT provides complementary information about bony anatomy and sellar remodeling but offers less lesion characterization than MRI 1

Endocrine Assessment

• Perform comprehensive hormonal screening including thyroid function tests (TSH, T3, T4), morning cortisol and ACTH, prolactin, sex hormones (LH, FSH, testosterone/estradiol), and growth hormone/IGF-1 1, 3
• Up to 48% of pediatric sellar lesions demonstrate thyroid hormone deficiencies, and approximately 28% show elevated prolactin levels 3
• Approximately 30% of patients demonstrate some degree of hypopituitarism, though many remain asymptomatic 3

Ophthalmologic Evaluation

• Measure visual acuity with age-specific tests recorded as logarithm of the minimum angle of resolution 1
• Perform age-appropriate visual field testing, which is critical for macroadenomas and post-surgical microadenomas 1
• Consider optical coherence tomography in children ≥3 years old, as thinner retinal nerve fiber layer correlates with visual field loss and optic neuropathy 1
• Visual recovery is unlikely after the first post-operative month, and age <6 years with visual symptoms at diagnosis indicates increased risk of poor visual outcomes 1

Differential Diagnosis Considerations

Most Common Pediatric Sellar Lesions

• Craniopharyngiomas account for the majority of pediatric sellar masses, while pituitary adenomas are extremely uncommon during childhood 2, 4
• Other entities include arachnoid cysts, germ cell tumors, optic pathway gliomas, and rarely meningiomas 5, 6, 7
• The type and frequency of sellar lesions in children differ significantly from adult presentations, with pediatric tumors showing predilection for unusual anatomical locations including intraventricular, parasellar, cavernous, and infratentorial sites 1, 6

Treatment Approach

Surgical Management

• For most sellar tumors except prolactinomas, transsphenoidal resection remains the mainstay of treatment 2, 4
• Complete resection is the treatment of choice when feasible, with modern techniques including image-guided surgery (frameless stereotaxy) improving precision and reducing surgical side-effects 1
• Endoscopic transsphenoidal surgery has shown promise as a less invasive primary treatment modality 2
• For tumors involving skull base, cavernous sinus, or petrous bone, joint procedures with pediatric neurosurgeon and skull base specialist are recommended 1
• Intraoperative electrophysiological monitoring of relevant cranial nerves is recommended when operating near critical structures 1

Medical Management

• Dopamine agonist therapy should be considered as first-line treatment for most prolactin-secreting adenomas 4
• Medical management may be appropriate for certain hormone-secreting tumors that respond to dopamine analogs or other medications 1

Adjuvant Therapy

• Radiotherapy is considered for WHO grade II/III tumors, multiple relapses, invasion of adjacent brain, extensive tissue invasion, or contraindication to surgery 1
• Stereotactic radiosurgery has shown promise as an adjuvant treatment modality 2
• Less invasive alternatives include intracavitary therapy and debulking followed by radiation therapy for selected cases 4

Histopathological Assessment

• Obtain histopathological assessment of operated tissue including immunostaining for pituitary hormones and Ki-67, with additional immuno-profiling when relevant 1
• Ki-67 ≥3% combined with local invasion on imaging predicts a 25% recurrence rate after surgery in pediatric cases 1
• Multilevel approach should include pituitary hormones, cytokeratin, and Ki-67 as basic reporting, with transcription factors added for immunonegative or unusual staining patterns 1
• O6-methylguanine-DNA methyltransferase immunohistochemistry can be useful if considering temozolomide therapy for aggressively growing tumors 1

Critical Pitfalls to Avoid

• Do not delay surgical planning for resectable lesions, as visual recovery is unlikely after the first post-operative month and younger children have worse visual outcomes 1
• Avoid attempting complete resection of tumors enveloping major vessels (carotid artery, venous sinuses) or involving vital neural structures, as risks may outweigh benefits 1
• Do not overlook the need for lifelong endocrine surveillance, as hormonal deficiencies may develop or progress over time 1, 3
• Recognize that some tumors may require staged multiple procedures or partial resection if blood loss threatens life, particularly with giant tumors 1
• Ensure multidisciplinary discussion regarding risks of surgical death or significant neurological deficits versus benefits of alternative therapies for complex cases 1