Special Senses System

Lacrimal Gland - Karyomegaly

Narrative
Comment:
Lacrimal gland karyomegaly is characterized by lacrimal gland acinar cells with enlarged, often pleomorphic nuclei with prominent nucleoli and/or polyploidy (Figure 3 and Figure 4). Intranuclear pseudoinclusions are sometimes present (Figure 3) and are most likely cytoplasmic invaginations. Affected cells generally exhibit increased cytoplasmic volume (overall cytomegaly). This very common change occurs in rats and mice (with rats more frequently affected) and tends to increase in incidence and severity with age. Male rodents are more frequently and extensively affected than females, which contributes to the sexual dimorphism (overall relatively larger lacrimal glands) of this organ in mice and especially in rats.
Recommendations:
Karyomegaly in the lacrimal gland should be diagnosed only if there are treatment-related differences in incidence and/or severity. When diagnosed, it should be graded.
References:

Cornell-Bell AH, Sullivan DA, Allansmith MR. 1985. Gender-related differences in morphology of the lacrimal gland. Invest Ophthalmol Vis Sci 26:1170-1175.

Abstract: https://pubmed.ncbi.nlm.nih.gov/4019110/

Gaertner DJ, Lindsay JR, Stevens JO. 1988. Cytomegalic changes and "inclusions" in lacrimal glands of laboratory rats. Lab Anim Sci 38:79-82.

Abstract: http://ebm.sagepub.com/content/101/1/164.short

Hebel R, Stromberg MW. 1986. Sensory organs. In: Anatomy and Embryology of the Laboratory Rat, 2nd ed. BioMed Verlag, Wörthsee, Germany, 218-224.

Krinke GJ, Schaetti PR, Krinke A. 1996. Nonneoplastic and neoplastic changes in the Harderian and lacrimal glands. In: Pathobiology of the Aging Mouse, Vol 2 (Mohr U, Dungworth DL, Capen CC, Carlton WW, Sundberg JP, Ward JM, eds). International Life Sciences Institute Press, Washington, DC, 139-152.

National Toxicology Program. 1990. NTP TR-376. Toxicology and Carcinogenesis Studies of Allyl Glycidyl Ether (CAS No. 106-92-3) in Osborne-Mendel Rats and B6C3F1 Mice (Inhalation Studies). NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/8892

National Toxicology Program. 1999. NTP TR-489. Toxicology and Carcinogenesis Studies of Magnetic Field Promotion (DMBA Initiation) in Female Sprague-Dawley Rats (Whole-Body Exposure/Gavage Studies). NTP, Research Triangle Park, NC.

Abstract: https://ntp.niehs.nih.gov/go/10168

Percy DH, Wojcinski ZW, Schunk MK. 1989. Sequential changes in the Harderian and exorbital lacrimal glands in Wistar rats infected with sialodacryoadenitis virus. Vet Pathol 26:238-245.

Full Text: http://vet.sagepub.com/content/26/3/238.full.pdf

Tier H. 1949. On the sizes of the nuclei in the glandula infraorbitalis of the white rat. Acta Pathol Microbiol Scand 26:620-625.

Abstract: http://onlinelibrary.wiley.com/doi/10.1111/j.1699-0463.1949.tb00761.x/abstract

Walker R. 1958. Age changes in the rat’s extraorbital lacrimal gland. Anat Rec 132:49-69.

Abstract: http://onlinelibrary.wiley.com/doi/10.1002/ar.1091320104/abstract

Yoshitomi K, Boorman GA. 1990. Eye and associated glands. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, CA, 239-260.

Abstract: https://www.ncbi.nlm.nih.gov/nlmcatalog/9002563
  • Image of karyomegaly in the lacrimal gland from a male B6C3F1 mouse in a chronic study
    Lacrimal gland - normal in a male B6C3F1 mouse from a chronic study. Normal lacrimal gland; compare to Figure 3 and Figure 4.
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Lacrimal gland - Normal in a male B6C3F1 mouse from a chronic study. Normal lacrimal gland for comparison to Figure 3 and Figure 4.
Lacrimal gland - Normal in a male B6C3F1 mouse from a chronic study. Normal lacrimal gland for comparison to Figure 3 and Figure 4.
Lacrimal gland - normal in a male B6C3F1 mouse from a chronic study. Normal lacrimal gland; compare to Figure 3 and Figure 4., basic_html
Lacrimal gland - normal in a male B6C3F1 mouse from a chronic study. Normal lacrimal gland; compare to Figure 3 and Figure 4., basic_html
Lacrimal gland - Karyomegaly in a male Osborne-Mendel rat from a chronic study. Karyomegaly is characterized by acinar cells with enlarged, often pleomorphic nuclei (arrow) and frequent intranuclear pseudoinclusions (arrowhead).
Lacrimal gland - Karyomegaly in a male Osborne-Mendel rat from a chronic study. Karyomegaly is characterized by acinar cells with enlarged, often pleomorphic nuclei (arrow) and frequent intranuclear pseudoinclusions (arrowhead).
Lacrimal gland - Karyomegaly in a male Osborne-Mendel rat from a chronic study. Karyomegaly is characterized by acinar cells with enlarged nuclei (arrow), which are often pleomorphic.
Lacrimal gland - Karyomegaly in a male Osborne-Mendel rat from a chronic study. Karyomegaly is characterized by acinar cells with enlarged nuclei (arrow), which are often pleomorphic.

Author

Margarita M. Gruebbel, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Reviewers

Ruth E. Hurley, DVM, PHD, DACVP
Senior Veterinary Pathologist
Huntingdon Life Sciences
North Brunswick, NJ

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