Pituitary Tumors in Children and Adolescents

Extract

Tumors occupying the pituitary fossa are of two main types: craniopharyngiomas, the most common tumor causing hypopituitarism in childhood, and pituitary adenomas. Virtually all tumors of this region are benign. Tumors that metastasize to the pituitary during childhood are exceedingly rare. Neoplastic or infiltrative processes of the pituitary area, including gliomas arising from the optic chiasm and surrounding region, meningiomas, germ cell tumors arising from the pituitary stalk, and granulomatous diseases that include histiocytosis X, tuberculosis, and sarcoidosis, may interfere with pituitary function. This review will focus on neoplastic diseases that arise from the pituitary gland or its anlagen.

Craniopharyngioma

Craniopharyngiomas account for 80–90% of neoplasms arising in the pituitary region. They originate from squamous rest cells in the remnant of Rathke’s pouch between the adenohypophysis and neurohypophysis. Rathke’s pouch is a cystic diverticulum from the roof of the embryonic mouth that gives rise to the adenohypophysis. Tumors may be completely intrasellar (25%) where they may radiologically mimic a pituitary adenoma, solely extrasellar, or a combination of both. Although craniopharyngiomas may arise at any time in life, there is a bimodal peak in incidence at 5–14 yr of age and again after the age of 50 (1). The overall incidence of craniopharyngiomas in the United States is 1.3 per 10⁶ person years and does not seem to vary with race or gender (1).