Pituitary gigantism
ICD-10 E22.0 · ICD-11 5A60.0.1

Pituitary Gigantism in McCune-Albright Syndrome When Somatostatin Analog Treatment Has Not Achieved IGF-1 Control

Clinical scenario

McCune-Albright syndrome (MAS) arises from a postzygotic activating mutation of GNAS and can involve pituitary over-activity presenting as gigantism in children and adolescents. Concomitant craniofacial fibrous dysplasia makes surgical cure exceptional in this setting, making sustained medical therapy the cornerstone of management.

Previous treatment — failure condition

Initial medical therapy with a first-generation somatostatin analog (octreotide or lanreotide) was employed. This protocol applies when that approach has not achieved adequate hormonal control of IGF-1 — the primary treatment target in MAS-associated pituitary gigantism.

Next-line approach

The subsequent step involves a specific targeted medical agent — pegvisomant — with the goal of achieving IGF-1 control. The full structured regimen, including decision criteria and monitoring parameters, is available in the complete protocol.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1016/B978-0-12-814537-1.00002-6

In MAS, mosaicism for a postzygotic activating mutation of GNAS leads to variable and diverse pathology affecting multiple tissues, classically, fibrous dysplasia of the bone, hormonal over-activity, and distinctive café au lait macules.

Acromegaly forms a part of the MAS spectrum and rarely can have an early onset in children/adolescents, leading to pituitary gigantism.

Pegvisomant is, is contrast, an important treatment option for MAS patients with acromegaly or pituitary gigantism, as control of IGF-1 is usually achieved in compliant patients.

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