Endocrine Abstracts

Introduction: The development of pituitary gland is orchestrated by genetic signals, transcription factors and signaling molecules with a crucial role in cell proliferation and differentiation. Anterior pituitary gland is formed by both granular (secretory) and agranular cells represented mainly by follicular-stellate cells. It is known that these cells form a supporting network around secretory cells and produce many kind of growth factors, but their major function remains unknown. Development of follicular-stellate cells and their implications in pathological processes of the adenohypophysis is scarcely covered in the literature.

Material and methods: 54 newborn pituitary glands obtained from autopsy (ages between 0 days and 6 months) were evaluated using morphological (hematoxylin and eosin) and immunohistochemical staining (glial fibrillary acidic protein and S100 protein).

Results: The histopathological examination of the anterior pituitary gland revealed acidophilic-basophilic differentiation starting with 0 days. Pituitary anterior cells are distributed in nests and cords in first month after birth. The nests became dominant, starting one month, like in normal adult gland. Follicular-stellate cells, evaluated using GFAP and S100 protein, presented isolated IHC expression during first month, morphologically having oval and round shape. The follicular-stellate cells density increased progressively starting with five-seven days, with a more relevant IHC cytoplasmic reaction. The one-month specimens present follicular-stellate cells having star-like appearance with a strong IHC expression, being predominantly located in perivascular areas. Compared to S100 protein, GFAP analysis revealed more details about cell morphology (shape, orientation, tendency to form a network).

Conclusions: Few data regarding newborn pituitary gland morphological and immunohistochemical characteristics are found in the literature, even less about follicular-stellate cells. Their role is incompletely described, and it may be associated with normal and pathological development of pituitary gland. Newborn pituitary gland shows different microscopical aspect compared to adult. Follicular-stellate cells density increases with age, starting one week after birth.