Reproductive System, Male

Prostate, Acinus - Dilation

Narrative

Comment:

Ectasia or dilation of the prostate is characterized by acini that are sometimes distended with secretory material and lined by attenuated epithelial cells (Figure 1, Figure 2, Figure 3, and Figure 4). There may be marked acinar enlargement, particularly with significant compression of surrounding unaffected acini and parenchyma, with the dilation appearing cystic (Figure 3 and Figure 4). Affected acinar secretory material can exhibit either a near normal staining reaction (Figure 1 and Figure 2) or can be poorly stained as in the quiescent gland shown in Figure 3 and Figure 4. Affected acini can be observed in any lobe and can involve either a part or the entire lobe. This is likely an age-related lesion and may be associated with interstitial inflammation.

Recommendations:

Prostatic dilatation should be recorded and given a severity grade during histopathologic evaluation of prostate from toxicity studies. The affected lobe(s) should be identified if possible and indicated in the tissue identification (e.g., prostate, dorsolateral lobe, acinus - dilation, moderate). If paired lobes are both affected, the diagnosis should be qualified as bilateral, with severity based on the more severely affected gland.

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

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

Greaves P. 2007. Male genital tract. In: Histopathology of Preclinical Toxicity Studies: Interpretation and Relevance in Drug Safety Evaluation. 3rd ed. Academic Press, San Diego, 661-716.

Abstract: http://www.sciencedirect.com/science/book/9780444527714

All Images

Prostate, Acinus - Dilation. Acinar dilation in a male F344/N rat from a chronic study.

Prostate, Acinus - Dilation. Higher magnification of Figure 1. Acinar dilation in a male F344/N rat from a chronic study.

Prostate, Acinus - Dilation. Three dilated glands are filled with neutrophils and cellular debris (arrows) in a male F344/N rat from a chronic study.

Prostate, Acinus - Dilation. Higher magnification of Figure 3. Acinar dilation in a male F344/N rat 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