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October 1976

Prolactin-Secreting Pituitary Tumor in Early Adolescence: Hormonal and Electron Microscopical Studies

Author Affiliations

From the Department of Medicine, University of Hawaii School of Medicine and the Fronk Clinic, Honolulu.

Arch Intern Med. 1976;136(10):1164-1168. doi:10.1001/archinte.1976.03630100076020

A 13-year-old boy was evaluated for an enlarged sella. There were no consistent visual field defects, and carotid arteriograms and pneumoencephalograms showed no extrasellar abnormality. The endocrine workup demonstrated a subnormal growth hormone reserve. The only other, but most striking abnormality, was an excessively high serum prolactin level, which was partially suppressed with levodopa. A chromophobe pituitary tumor was removed that had histological features suggestive of malignant neoplasm. Characteristics of a prolactin-secreting tumor were confirmed by electron microscopy. The serum prolactin levels decreased substantially after surgery and further after a course of pituitary irradiation; however, they continue to be elevated above normal. Prolactin determinations play an integral part in the evaluation for a possible pituitary tumor—not only for diagnostic purposes, but also to provide a parameter of future tumor activity in an established case. Electron microscopical studies are helpful in identifying the tumor as source of the excessive prolactin secretion.

(Arch Intern Med 136:1164-1168, 1976)