Endocrine System

Thyroid Gland - C Cell Hyperplasia

    Narrative
    Thyroid gland, C cell - Hyperplasia in a treated female F344 rat from a chronic study. Aggregates and small nests of C cells have replaced follicles in this thyroid gland.
    Thyroid gland, C cell - Hyperplasia in a treated female F344 rat from a chronic study. Higher magnification of Figure 1 shows the contiguous nests of C cells surrounding small follicles.
    Thyroid gland, C cell - Hyperplasia in a control male F344 rat from a chronic study. A focal proliferation of C cells is present in this thyroid gland (arrow).
    Thyroid gland, C cell - Hyperplasia in a control male F344 rat from a chronic study. Higher magnification of Figure 3 shows illustrates the high nuclear-to-cytoplasmic ratio in this focal proliferation of C cells.

    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

    Susan A. Elmore, MS, DVM, DACVP, DABT, FIATP
    Staff Scientist, NTP Pathologist
    NTP Pathology Group
    National Toxicology Program
    National Institute of Environmental Health Sciences
    Research Triangle Park, NC