Endocrine System

Adrenal Gland - Cyst

Narrative

Comment:

Adrenal cysts (Figure 1, Figure 2, and Figure 3) are lined by cuboidal to ciliated columnar epithelium and may contain amorphous to flocculent, eosinophilic material. They may be located in the cortex or medulla and may cause variable distortion or compression of the adjacent tissue. These minor findings are more common in mice than in rats and are usually incidental, spontaneous changes of no clinical or toxicologic relevance. Cortical cysts must be distinguished from angiectasis (dilated vascular channels containing blood and lined by flat endothelial cells). Cortical cysts in rats must also be distinguished from cystic degeneration, a common lesion in certain rat strains, which features irregular, often large cavitated spaces filled with proteinaceous fluid but lack the epithelial lining of true cysts (Figure 2 and Figure 3).

Recommendations:

Adrenal gland cysts should be diagnosed only if they occur with treatment-related increased incidences. In these cases, they should be diagnosed but not assigned of a severity grade. When diagnosed, an appropriate site modifier (i.e., cortex or medulla) should be included in the diagnosis to indicate the location of the cyst.

References:

National Toxicology Program. 1993. NTP TR-434. Toxicology and Carcinogenesis Studies of 1,3-Butadiene (CAS No. 106-99-0) in B6C3F1 Mice (Inhalation Studies). NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/6012

Nyska A, Maronpot RR. 1990. Adrenal gland. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 509-536.

Abstract: http://www.cacheriverpress.com/books/pathmouse.htm

All Images

Adrenal gland, Cortex - Cyst in a female B6C3F1/N mouse from a chronic study. An adrenal cortical cyst (C), filled with amorphous pale eosinophilic material, compresses adjacent cortex and medulla.

Adrenal gland, Cortex - Cyst in a female B6C3F1/N mouse from a chronic study (higher magnification of Figure 1). A single layer of well-differentiated, low columnar epithelial cells (arrow) lines an adrenocortical cyst.

Adrenal gland, Cortex - Cyst in a female B6C3F1/N mouse from a chronic study. Cortical cyst (C) lined by cuboidal to columnar epithelial cells (arrows) contains flocculent, pale eosinophilic material.

Authors and Reviewers

Authors

Mark J. Hoenerhoff, DVM, PhD, DACVP
Associate Professor
Veterinary Pathologist, In Vivo Animal Core
Unit for Laboratory Animal Medicine
University of Michigan
Ann Arbor, MI

Georgette D. Hill, D.V.M., Ph.D.
Toxicologic Pathologist/Assistant Pathology Program Manager
Comparative Molecular Pathology Division
Integrated Laboratory Systems, Inc.
Research Triangle Park, NC

Margarita M. Gruebbel, 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

Gordon Flake, MD
Staff Scientist
NTP Pathologist
Cellular and Molecular Pathology Branch
National Institute of Environmental Health Sciences
Research Triangle Park, NC