Alimentary System

Salivary Gland, Parotid, Acinus - Hypertrophy

Narrative
Comment:
Diffuse hypertrophy of parotid salivary gland acinar cells not associated with basophilic foci is rare in NTP studies. Likewise, diffuse acinar cell hypertrophy of the submandibular and sublingual salivary glands is rare in B6C3F1 mice and Fischer 344 rats. Acinar cell hypertrophy (Figure 2) is characterized by increased cell size primarily due to an increase in cytoplasm, although the nuclei are also usually larger in hypertrophied cells. The intense basophilia seen with hypertrophic basophilic foci is not present, and the cells are typically not as large. Diffuse hypertrophy of acinus cells often can be a subtle change requiring close comparison with control animals.
Recommendations:
Salivary gland acinar hypertrophy should be diagnosed and graded based on the degree of increase in acinar cell size and number of cells affected. Multifocal hypertrophy would be assigned a higher severity grade than focal hypertrophy. If the hypertrophy is diffuse throughout the gland, then the modifier "diffuse" should be added to the diagnosis.
References:

Botts S, Jokinen M, Gaillard ET, Elwell MR, Mann PC. 1999. Salivary, Harderian, and lacrimal glands. In: Pathology of the Mouse (Maronpot RR, ed). Cache River Press, St Louis, MO, 49-80.

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

National Toxicology Program. 1992. NTP TOX-16. Toxicity Studies of Glyphosate (CAS No. 1071-83-6) Administered in Dosed Feed to F344/N Rats and B6C3F1 Mice. NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/11968

Neuenschwander SB, Elwell MR. 1990. Salivary glands. In: Pathology of the Fischer Rat (Boorman GA, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, CA, 31-42.

Abstract: https://www.ncbi.nlm.nih.gov/nlmcatalog/9002563
  • Image of normal comparison to hypertrophy in the parotid salivary gland acinus from a male F344/N rat in a subchronic study

    Normal parotid salivary gland from a male F344/N rat from a subchronic study.

Enlarge Image
Enlarge All Images
Normal parotid salivary gland from a male F344/N rat from a subchronic study.
Normal parotid salivary gland from a male F344/N rat from a subchronic study.
Salivary gland, Parotid, Acinus - Hypertrophy in a male F344/N rat from a subchronic study. The acinar cells are diffusely enlarged.
Salivary gland, Parotid, Acinus - Hypertrophy in a male F344/N rat from a subchronic study. The acinar cells are diffusely enlarged.

Authors:

Linda H. Kooistra, DVM, PhD, DACVP
Pathologist
Charles River Laboratories, Inc.
Research Triangle Park, NC

Abraham Nyska, DVM, Diplomate ECVP, Fellow IATP
Expert in Toxicologic Pathology
Visiting Full Professor of Pathology
Sackler School of Medicine, Tel Aviv University Timrat Israel

Reviewers:

Joel R. Leininger, DVM, PhD
Senior Pathologist
MedImmune
Washington, DC

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