VANISHING PSAMMOMA BODIES IN THE ANTERIOR-PITUITARY OF THE HUMAN NEWBORN - AN IMMUNOHISTOCHEMICAL AND HISTOMETRIC STUDY

Adenohypophyses of human newborns contain characteristic psammoma bodi es. Their numbers are maximal within 2 weeks of the neonatal period an d diminish thereafter. They are very rare in infant pituitaries, seemi ng to disappear by shrinkage in that there is a significant direct cor relation between their number and size, The bodies were found to conta in a high concentration of endogenous peroxidase, thus suggesting that the enzyme may be responsible for their disappearance, A statistical majority of psammoma bodies were located within follicular lumens. By immunohistochemistry, the follicular epithelium surrounding psammoma b odies showed immunoreactivity for various pituitary hormones, Light mi croscopy demonstrated that adenohypophysial cells surrounding psammoma bodies contain randomly scattered granules or globules exhibiting per oxidase activity. Extrusion of such granules into follicular lumens ma y play a role in the genesis of the concretions. The conspicuous lamel lar nature of the calcified psammoma bodies suggests that waves of cal cium deposition occur during their morphogenesis. Despite histologic s imilarities, the histochemical characteristics of this type of psammom a body differ from those in other organs as well as from the calcifica tion encountered in prolactin (PRL)-producing pituitary adenomas.