Hepatobiliary System

Liver, Bile Duct - Cyst

Narrative

Comment:

Single and multiloculated biliary cysts can occur spontaneously in older rats and mice. They can occur as single dilated biliary structures, multiple adjacent dilated biliary structures (Figure 1 and Figure 2), or a multiloculated cyst (Figure 3). Biliary cysts may accompany hepatic toxicity and may be associated with peripheral or sub-basilar collagen deposition (Figure 4). They are typically lined by a single layer of flattened or low cuboidal epithelium (Figure 4), with little evidence of active proliferation. In contrast to cholangiomas, they do not compress the adjacent hepatic parenchyma.

Recommendations:

Small biliary cysts may occasionally be seen in untreated rats but are more often associated with treatment. Consequently, they should be documented whenever present and given a severity grade.

References:

Eustis SL, Boorman GA, Harada T, Popp JA. 1990. Liver. In: Pathology of the Fischer Rat (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 71-94.

Harada T, Enomoto A, Boorman GA, Maronpot RR. 1999. Liver and gallbladder. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 119-183.

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

National Toxicology Program. 2006. NTP TR-521. Toxicology and Carcinogenesis Studies of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (CAS No. 1746-01-6) in Female Harlan Sprague-Dawley Rats (Gavage Studies). NTP, Research Triangle Park, NC.

Full Text: https://ntp.niehs.nih.gov/ntp/htdocs/lt_rpts/tr521.pdf

Thoolen B, Maronpot RR, Harada T, Nyska A, Rousseaux C, Nolte T, Malarkey D, Kaufmann W, Kutter K, Deschl U, Nakae D, Gregson R, Winlove M, Brix A, Singl B, Belpoggi F, Ward JM. 2010. Hepatobiliary lesion nomenclature and diagnostic criteria for lesions in rats and mice (INHAND). Toxicol Pathol 38:5S-81S.

Full Text: http://tpx.sagepub.com/content/38/7_suppl/5S.full

All Images

Bile duct cysts in a female Harlan Sprague-Dawley rat from a chronic study.

Bile duct cysts in a female Harlan Sprague-Dawley rat from a chronic study (higher magnification of Figure 1).

Bile duct cyst-multiloculated cyst in a female Harlan Sprague-Dawley rat from a chronic study.

Bile duct cysts in a female Harlan Sprague-Dawley rat from a chronic study.

Authors and Reviewers

Author

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

Reviewers

John Cullen, VMD, PhD, DACVP, FIATP
Anatomic Pathology, Professor
North Carolina State University College of Veterinary Medicine
Raleigh, NC

David E. Malarkey DVM, PhD, DACVP, FIATP
Head, National Toxicology Program Pathology Group
Cellular and Molecular Pathology Branch
Division of the National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC