Table 1.

Tumor classification that was used for evaluating Apc^Min mice exposed to B(a)P via saturated or unsaturated fat.

Tumor type	Description
Polyp	A benign tumor
Adenoma	A benign (noninvasive) circumscribed neoplasm composed of dysplastic epithelium (Boivin et al. 2003). Also referred to as tubular adenoma or adenomatous polyp.
Advanced adenoma	Large adenoma (>5 mm) or with high-grade dysplasia
Dysplasia	Morphologic features characteristic of intraepithelial neoplasia in the intestine. Subdivided into low-grade dysplasia (low nucleus to cytoplasm ratio, elongated nuclei with maintenance of polarity) and high-grade dysplasia (architectural changes such as cribriform or complex glands, high nucleus to cytoplasm ratio, loss of polarity).
Adenocarcinoma	Malignant neoplasm of glandular epithelium penetrating through the muscularis mucosae. Categorized by grade and histologic type.
Mucinous carcinoma	Histologic type of carcinoma characterized by >50% of tumor composed of extracellular mucin.
Signet ring cell carcinoma	Histologic type of carcinoma characterized by >50% of tumor composed of signet ring cells.
Undifferentiated carcinoma	Solid growth pattern without glandular structures; high-grade carcinoma.