Reproductive System, Male

Epididymis, Epithelium - Degeneration

Narrative
Comment:
Degeneration and necrosis of the efferent duct or epididymal epithelium are unusual findings, either as a background lesion or as a chemically induced lesion. The lesion is characterized by attenuation and sloughing of the epithelial lining of the epididymal duct. The finding should not be confused with the presence of sloughed testicular germ cells in the epididymal lumen (also see Epididymis - Duct - Exfoliated Germ Cell ), where the epididymal epithelium remains normal and intact. If there is a breach of the epithelial lining, it is generally accompanied by an inflammatory infiltrate due to breakdown in the blood-epididymal barrier resulting in exposure of immune cells to the antigenically foreign sperm. Epithelial degeneration has been described in response to methyl chloride inhalation.
Recommendations:
Epithelial degeneration should be recorded and graded and should be discussed in the pathology narrative if the incidence and/or severity appears to be related to chemical administration. If both epididymides are involved, the diagnosis should be clarified as bilateral and the severity score based on the more severely affected epididymis. Correlation with any spermatogenic disturbances should be noted in the pathology narrative to aid interpretation. Cytoplasmic vacuolation, although a form of degeneration, should be recorded separately (also see Epididymis - Epithelium - Vacuolation ).
Related Links:
Epididymis - Duct - Exfoliated Germ Cell
Epididymis - Epithelium - Vacuolation
References:

Chapin RE, White RD, Morgan KT, Bus JS. 1984. Studies of lesions induced in the testis and epididymis of F-344 rats by inhaled methyl chloride. Toxicol Appl Pharmacol 76:328-343.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/6388032

Chellman GJ, Morgan KT, Bus JS, Working PK. 1986. Inhibition of methyl chloride toxicity in male F-344 rats by the anti-inflammatory agent BW-755C. Toxicol Appl Pharmacol 85:365-379.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/3094195

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

Klinefelter GR. 2002. Actions of toxicants on the structure and function of the epididymis. In: The Epididymis: From Molecules to Clinical (Robaire B, Hinton BT, eds). New York, Kluwer/Plenum, 353-370.

Abstract: http://www.springer.com/medicine/urology/book/978-0-306-46684-7
  • Image of epithelial degeneration in the epididymis from a male B6C3F1 mouse in a chronic study

    Epididymis, Epithelium - Degeneration. Sloughed epididymal epithelium in the duct lumen in a B6C3F1 mouse from a chronic study.

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Epididymis, Epithelium - Degeneration. Sloughed epididymal epithelium in the duct lumen in a B6C3F1 mouse from a chronic study.
Epididymis, Epithelium - Degeneration. Higher magnification of Figure 1 showing a focal area of cellular degeneration of epithelial sloughing (arrow) in a B6C3F1 mouse from a chronic study.
Epididymis, Epithelium - Degeneration. Attenuation and sloughing of epididymal epithelium in the epididymis of a rat. (Photograph courtesy of D. Creasy).
Epididymis, Epithelium - Degeneration. Higher magnification of Figure 3 showing attenuated epithelial lining and sloughed epithelial cells in the epididymis of a rat. (Photograph courtesy of D. Creasy.)

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