Clinicopathological features of growth hormone-producing pituitary adenomas: difference among various types defined by cytokeratin distribution pattern including a transitional form - PubMed (original) (raw)

Clinicopathological features of growth hormone-producing pituitary adenomas: difference among various types defined by cytokeratin distribution pattern including a transitional form

Abdulkader Obari et al. Endocr Pathol. 2008 Summer.

Abstract

Pituitary adenomas producing almost exclusively growth hormones (GH) have been ultrastructurally classified into two distinct types: densely granulated somatotroph (DG) adenomas and sparsely granulated (SG) adenomas. Fibrous body (FB), an intracytoplasmic globular aggregation of cytokeratin (CK) filaments, is a hallmark of SG adenomas. Under light microscope, FB could be identified by CK immunohistochemistry as a dot-pattern immunoreaction versus a perinuclear pattern for cells without FB. However, it has been noted that numerous adenomas contain mixed populations of the two patterns. To clarify clinicopathological characteristics of the adenomas with mixed populations ("intermediate type" adenomas) and to confirm clinicopathological differences between strictly defined DG-type and SG-type adenomas, we performed this study on 104 GH cell adenomas. Having segregated "intermediate-type" adenomas (26 cases), we found significant differences between typical DG-type (47 cases) and SG-type adenomas (31 cases); SG-type adenomas had younger ages (44 vs. 50), higher frequency of macroadenomas (86% vs. 58%), invasiveness (65% vs. 38%), advanced grades (3 or 4) in Knosp's classification (50% vs. 24%), and weaker immunoreaction for GH, beta-TSH, alpha-subunit, E-cadherin, and beta-catenin. Clinicopathological characteristics of "intermediate-type" adenomas were identical to those of DG-type adenomas. These findings confirm that SG-type adenoma is a distinct section of GH cell adenomas with special properties and biological behavior, and suggest that intermediate-phenotype adenomas are enrolled in DG-type adenomas. Special properties and biological behavior of SG-type adenomas may appear after the majority of tumor cells possess a fully developed fibrous body.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Arch Pathol Lab Med. 1985 Jun;109(6):505-8 - PubMed
    1. Pathol Int. 2001 Jul;51(7):532-42 - PubMed
    1. Endocr Pathol. 2002 Winter;13(4):341-51 - PubMed
    1. J Clin Endocrinol Metab. 2005 Nov;90(11):6290-5 - PubMed
    1. Neurosurgery. 1993 Oct;33(4):610-7; discussion 617-8 - PubMed

MeSH terms

Substances

LinkOut - more resources