CALCIFIED CONCRETIONS IN THE ANTERIOR-PITUITARY GLAND OF THE FETUS AND THE NEWBORN - A LIGHT AND ELECTRON-MICROSCOPIC STUDY

Calcified concretions including typical laminated psammoma bodies can be detected on routine hematoxylin-eosin (H&E) examination of fetal an d neonatal anterior pituitary glands. This finding has seldom been rep orted in the literature and, to the authors' knowledge, no ultrastruct ural examinations of fetal or neonatal pituitary calcifications have b een reported to date. In this study, histological sections of anterior pituitary glands from 200 fetuses and infants ranging in age from 15 weeks of gestation to 1 year of life revealed calcified concretions in all the cases up to 1 month of life. They decreased in incidence post natally and were not found after 6 months of age. Most were round to o void, basophilic or eosinophilic, often laminated, and measured betwee n 5 and 30 mu m in diameter. Immunohistochemical stains showed that th e calcifications followed no particular pattern of distribution among the most prevalent pituitary cell types. Ultrastructural examination r evealed small single or multiple intracellular calcified deposits, and larger, sometimes laminated, extracellular calcifications, suggesting an intracellular origin for the concretions with cell death occurring concomitant with their formation. This phenomenon, which to some exte nt resembles the formation of psammoma bodies in certain tumors, seems to represent a distinctive morphological type of developmental cell d eath. Apoptosis, a more common form of developmental cell death, was a lso found in some of the sections. Pathologists should be aware of the fact that calcified concretions represent a normal finding in the ant erior pituitary gland of fetuses and young infants. Their mere presenc e in cases of fetal or perinatal demise with no other pertinent findin gs should not be attributed to intrauterine viral infections or ischem ic-anoxic events. Copyright (C) 1996 by W.B. Saunders Company