Table 4.

Summary of published and proposed refined grading schemes for the prostate glands of TRAMP mice.

Grading Scheme	Number of Different Lesions	Number of Preneoplastic Lesions	Terminology for Preneoplastic Lesions	Definition of Invasion	Numerical Score
Gingrich et al. (1999)	5	2	PIN	Epithelial cells within the stroma-surrounding glands; rounded nuclei present within the fibromuscular stroma surrounding glands	No
Kaplan-Lefko et al. (2003)	5	1	PIN	Epithelial cells within smooth muscle stroma; increased number of small glandular structures with associated desmoplasia	No
Suttie et al. (2003)	6	3	Hyperplasia	Islands of epithelial cells within the smooth muscle stroma appear less well differentiated and are not closely associated with the outline of epithelium lining the gland	Yes: distribution-adjusted| lesion grade
Bar Harbor Meeting, 2004	5	1	Mouse PIN (mPIN)	Penetration of the basement membrane by epithelial cells; recognized based on presence of desmoplasia adjacent to the epithelial cells that have invaded into the smooth muscle, adequate distance separating the cells within the smooth muscle from the epithelial cells lining the gland, or clear evidence of the basement membrane being penetrated (determined using immunohistochemistry, special stains, or electron microscopy)	No
Chiaverotti et al. (2008)	6	3	Atypical hyperplasia of Tag	Presence of stromal reaction to the invading epithelial cells	No
Berman-Booty et al. (2011)	7	3	PIN	Presence of epithelial cells in the underlying smooth muscle, with cells crossing the basement membrane and replacement of the normal smooth muscle surrounding gland by reactive fibroblasts and myoepithelial cells	Yes: sum of the adjusted lesion scores