A new look at pituitary adenomas: structure elucidating function.

Cases of seven different types of surgically resected pituitary adenoma are described. Included are tumours secreting prolactin or growth hormone or both, and nonfunctioning tumours--undifferentiated and oncocytic tumours, and one tumour with cells of the adrenocorticotropin-melanocyte-stimulating hormone type. The final interpretation of a case of pituitary adenoma should include an assessment of thorough morphologic studies, using not only routine staining and light microscopy but also immunostaining and electron microscopy, to complement the biochemical, radiologic and clinical evaluation.