Endocrine System

Pituitary Gland - Hyperplasia

    Narrative
    Pituitary Gland, Pars distalis - Hyperplasia in a female Harlan Sprague-Dawley rat from a chronic study. A small focus of hyperplasia (arrow) in the pars distalis is recognized by the paler staining cells.
    Pituitary Gland, Pars distalis - Hyperplasia in a female Harlan Sprague-Dawley rat from a chronic study. Higher magnification of Figure 1 shows the focus of hyperplasia in greater detail.
    Pituitary Gland, Pars distalis - Hyperplasia in a female Harlan Sprague-Dawley rat from a chronic study. Higher magnification of Figure 2 highlights the larger, paler staining cells in this focus of hyperplasia in the pars distalis.
    Pituitary Gland, Pars distalis - Hyperplasia in a female Harlan Sprague-Dawley rat from a chronic study. Multiple focal areas of hyperplasia consisting of paler staining cells compared with the surrounding parenchyma are present in the pars distalis.
    Pituitary Gland, Pars distalis - Hyperplasia in a male F344/N rat from a chronic study. The focus of hyperplasia consists of paler staining cells (compared with the surrounding normal parenchyma) and dilated blood-filled vascular structures which are consistent with minimal to mild angiectasis.
    Pituitary Gland, Pars intermedia - Hyperplasia in a male F344/N rat from a chronic study. This example of hyperplasia of the pars intermedia (asterisk) is characterized by a circumscribed focus of cells with abundant amphophilic cytoplasm without compression of the adjacent normal parenchyma.
    Pituitary Gland, Pars intermedia - Hyperplasia in a male F344/N rat from a chronic study. Higher magnification of Figure 6 shows that the hyperplastic focus in the pars intermedia is characterized by a circumscribed collection of cells with abundant amphophilic cytoplasm without compression of the adjacent normal parenchyma.

    Authors

    Robert R. Maronpot, DVM, MS, MPH, DACVP, DABT, FIATP
    Senior Pathologist
    Experimental Pathology Laboratories, Inc.
    Research Triangle Park, NC

    Amy Brix, DVM, PhD, DACVP
    Senior Pathologist
    Experimental Pathology Laboratories, Inc.
    Research Triangle Park, NC

    Reviewers

    Thomas J. Rosol, DVM, PhD, DACVP
    Professor of Veterinary Biosciences
    Senior Advisor, Life Sciences, Technology Commercialization and Knowledge Transfer
    The Ohio State University
    Columbus, OH

    Deepa B. Rao, BVSc, MS, PhD, DABT, DACVP
    NTP Pathologist (Contractor)
    Integrated Laboratory Systems, Inc.
    Research Triangle Park, NC