Pituitary Gigantism in an Adolescent Girl With Postsurgical Residual Disease Treated With Lanreotide

Pituitary gigantism (PG) is a rare endocrine disorder that may present with multiple pituitary hormone abnormalities in pediatric patients. A hallmark presentation is accelerated growth due to growth hormone (GH) excess. Current treatment modalities include surgery, radiation, and medical therapy. We describe a 14-year-old girl who presented with recurrent slipped capital femoral epiphysis with GH excess and multiple other hormonal abnormalities. A sellar mass was identified on magnetic resonance imaging of the brain and was surgically resected. The pathology report was consistent with pituitary gland adenoma with mammosomatotrophs hyperplasia. Post surgery, serial laboratory results showed persistently elevated growth factor and GH levels, and residual tumor was reported on follow-up imaging. Even though we found limited data on the efficacy and safety of a long-acting somatostatin analogue, lanreotide, in the treatment of PG, a total of 4 doses of lanreotide successfully reduced growth factor and GH levels to normal ranges in our patient. Repeat imaging 5 weeks post discontinuation of lanreotide showed reduction of residual tumor volume. This case reveals that a short course of lanreotide may be used as an effective medical treatment in pediatric patients with PG who have residual disease after surgical intervention.