Pituitary gigantism with intracerebral metastases

Gigantism is usually caused by a benign growth hormone (GH)- secreting pituitary tumor. We describe a case of gigantism with markedly increased serum GH concentrations and radiological evidence of meningocerebral metastases. The 16-year-old patient presented with vision loss and gait disturbance. His basal serum GH concentration was markedly elevated (1293-2070 μg/L) and did not decrease with an oral glucose load. There was biochemical evidence of hypogonadism with low follicle-stimulating hormone, luteinizing hormone, and testosterone (the serum prolactin level was normal). A 6-cm pituitary tumor with secondary hydrocephalus was found on computerized tomographic imaging. Because surgical excision with shunt placement was of limited clinical benefit, the patient underwent postoperative external beam radiation therapy. Serum GH levels were partially responsive to octreotide therapy, but treatment was incompletely effective due to noncompliance. At the age of 18 years, intracerebral, cerebellar, and meningeal metastases became evident on neuroimaging. Although a post mortem examination was not performed, death was caused by increased intracranial pressure and cerebral, as well as cerebellar, herniation.