Reproductive System, Male

Seminal Vesicle - Inflammation

Narrative

Comment:

Inflammation of the seminal vesicle can be acute with a neutrophilic infiltrate in the interstitial as well as in the glandular lumen (Figure 1 and Figure 2). In Figure 2 the inflammation has destroyed the glandular architecture. In Figure 3 and Figure 4 it is associated with squamous metaplasia of some affected glands. The inflammatory response may also be associated with hyperplasia (arrow, Figure 2) and epithelial necrosis (arrowhead, Figure 2). Inflammation can be a more chronic, primarily interstitial reaction, with breaking up of the mucosa into small glandular structures (Figure 5 and Figure 6). Seminal vesicle inflammation is a sporadic incidental finding seen in older rats and mice.

NTP studies have five standard categories of inflammation: acute, suppurative, chronic, chronic-active, and granulomatous. In acute inflammation, the predominant infiltrating cell is the neutrophil, though fewer macrophages and lymphocytes may also be present. There may also be evidence of edema or hyperemia. The neutrophil is also the predominant infiltrating cell type in suppurative inflammation, but they are aggregated, and many of them are degenerate (suppurative exudate). Cell debris from both the resident cell populations and infiltrating leukocytes, proteinaceous fluid containing fibrin, fewer macrophages, occasional lymphocytes or plasma cells, and, possibly, an infectious agent may also be present in the exudate. Grossly, these lesions would be characterized by the presence of pus. The tissue surrounding the exudate may have fibroblasts, fibrous connective tissue, and mixed inflammatory cells, depending on the chronicity of the lesion. Lymphocytes predominate in chronic inflammation. Lymphocytes also predominate in chronic-active inflammation, but there are also a significant number of neutrophils. Both lesions may contain macrophages. Granulomatous inflammation is another form of chronic inflammation, but this diagnosis requires the presence of a significant number of aggregated, large, activated macrophages, epithelioid macrophages, or multinucleated giant cells.

Recommendations:

The inflammation should be diagnosed and given a severity grade. When both seminal vesicles are involved, the diagnosis should be qualified as bilateral and the severity based on the more severely affected seminal vesicle. Hyperplasia and squamous metaplasia secondary to inflammation should not be diagnosed separately unless warranted by severity or especially dominant. Indication of secondary squamous metaplasia and/or hyperplasia can be described in the pathology narrative.

References:

Boorman GA, Elwell MR, Mitsumori K. 1990. Male accessory sex glands, penis, and scrotum. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 419-428.

Abstract: http://www.ncbi.nlm.nih.gov/nlmcatalog/9002563

Bosland MC. 1992. Lesions in the male accessory glands and penis. In: Pathobiology of the Aging Rat, Vol 1 (Mohr U, Dungworth DL, Capen CC, eds). ILSI Press, Washington, DC, 443-467.

Abstract: http://catalog.hathitrust.org/Record/008994685

Creasy D, Bube A, de Rijk E, Kandori H, Kuwahara M, Masson R, Nolte T, Reams R, Regan K, Rehm S, Rogerson P, Whitney K. 2012. Proliferative and nonproliferative lesions of the rat and mouse male reproductive system. Toxicol Pathol 40:40S-121S.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/22949412

Gordon LR, Majka JA, Boorman GA. 1996. Spontaneous nonneoplastic and neoplastic lesions and experimentally induced neoplasms of the testes and accessory sex glands. In: Pathobiology of the Aging Mouse, Vol 1 (Mohr U, Dungworth DL, Capen CC, Carlton WW, Sundberg JP, Ward JM, eds). ILSI Press, Washington, DC, 421-441.

Abstract: http://catalog.hathitrust.org/Record/008994685

Radovsky A, Mitsumori K, Chapin RE. 1999. Male reproductive tract. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 381-407.

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

Suwa T, Nyska A, Peckham JC, Hailey JR, Mahler JF, Haseman JK, Maronpot RR. 2001. A retrospective analysis of background lesions and tissue accountability for male accessory sex organs in Fischer-344 rats. Toxicol Pathol 29(4):467-478.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/11560252

Suwa T, Nyska A, Haseman JK, Mahler JF, Maronpot RR. 2002. Spontaneous lesions in control B6C3F1 mice and recommended sectioning of male accessory sex organs. Toxicol Pathol 30(2):228-234.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/11950166

All Images

Seminal Vesicle - Inflammation. Acute inflammation in a male B6C3F1 mouse from a chronic study.

Seminal Vesicle - Inflammation. Arrow indicates an area of hyperplasia, and arrowhead points to epithelial necrosis in a male B6C3F1 mouse from a chronic study.

Seminal Vesicle - Inflammation. Acute inflammation in a male Harlan Sprague-Dawley rat from a chronic study.

Seminal Vesicle - Inflammation. Higher magnification of Figure 3 showing squamous metaplasia in a male Harlan Sprague-Dawley rat from a chronic study.

Seminal Vesicle - Inflammation. Chronic inflammation in a male B6C3F1 mouse from a chronic study.

Seminal Vesicle - Inflammation. Higher magnification of Figure 5. Chronic inflammation in a male B6C3F1 mouse from a chronic study.

Authors and Reviewers

Authors

Dianne M. Creasy, PhD, Dip RCPath, FRCPath
Dianne Creasy Consulting LLC
Pipersville, PA

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

Dipak K. Giri, DVM, PHD, DACVP
Toxicologic Pathologist
Integrated Laboratory Systems, Inc.
Research Triangle Park, NC

Reviewers

Mark F. Cesta, DVM, PhD, DACVP
Staff Scientist, NTP Pathologist
Cellular and Molecular Pathology Branch
Division of the National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, 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