Human pituitary somatotroph adenoma and prolactinoma: An ultrastructural and immunoelectron microscopical study

Abstract

17 cases of pituitary somatotroph adenoma and 38 cases of prolactinoma were studied with electron microscopy and immunoelectron microscopy using protein A-gold complex. 4 adenomas were shown by immunoelectron microscopy to contain simultaneously growth hormone (GH)-producing and pcolactin (PRL)-producing cells. 6 cases were classified as densely granulated GH adenomas and 11 as sparsely granulated variant, wheceas only 3 adenomas out of 38 prolactinomas were identified as densely granulated adenomas. The present study showed that not all cells with fibrous bodies possessed secretory granules positive for GH, and in some cells with fibrous bodies. PRL-producing granules were also detected. Misplaced exocytosis was found frequently in the sparsely granulated prolactinomas. From these findings it may be suggested that fibrous bodies are not a morphological feature characteristic of pituitary somatotroph adenomas.

Keywords

pituitary adenomas / growth hormone / prolactin / fibrous bodies / immunoelectron microscopy

References

[1] KovacsK, HorvathE. HartmannWH, SobinLH. Tumors of the pituitary gland. Atlas of Tumour Pathology, 1986WashingtonArmed Forces Institute of Pathology

[2] TomitaT, et al.. Immunoelectron microscopy for growth hormone and prolactin in pituitary adenomas. Hum Pathol, 1987, 18: 367-74

[3] HorvathE, et al.. Acidophilic stem cell adenoma of the human pituitary. Arch Pathol Lab Med, 1977, 101: 594-9

[4] ChallaRV, et al.. Pathobiologic study of pituitary tumors: report of 62 cases with a review of the recent literature. Hum Pathol, 1985, 16: 873-84

[5] WangBL, et al.. Simplified purification and testing of colloidal gold probes. Histochemistry, 1985, 83: 109-15

[6] SilverMM. Postembedding immunoelectron microscopy using protein A-gold. Ultrastruct Pathol, 1987, 11: 693-703

[7] HorvathE, KovacsK. Morphogenesis and significance of fibrous bodies in human pituitary adenomas. Virchows Arch (Cell Pathol), 1978, 27: 69-78

[8] CarstensPH, BroghamerWL. Duodenal carcinoid with cytoplasmic whorls of microfilaments. J Pathol, 1978, 124: 235-8

[9] Alvarez-FernaudezE. Intracytoplasmic fibrillary inclusions in bronchial carcinoids. Cancer, 1980, 46: 144-51

[10] McNuttMA, et al.. Coexpression of intermediate filaments in human epithelial neoplasms. Ultrastruct Pathol, 1985, 9: 31-43

[11] GouldVE, et al.. Neuroendocrine skin carcinoma coexpressing cytokeratin and neurofilament proteins. Ultrastruct Pathol, 1985, 9: 83-90

[12] McNicolAM. Pituitary adenomas. Histopathology, 1987, 11: 995-1011

[13] HorvathE, KovacsK. Misplaced exocytosis: distinct ultrastructural feature in some pituitary adenomas. Arch Pathol, 1974, 97: 221-4

[14] RyderDR, et al.. Fine structural features of secretion in adenomas of human pituitary gland. Arch Pathol Lab Med, 1980, 104: 518-22