Table 3.

Comparison between Intraoral basal cell carcinoma (IOBCC) and peripheral ameloblastoma (PA)

	IOBCC	PA
Clinical	Appears malignant- resembles carcinoma; mixed red/white, maybe ulcerated	Appears benign: “bump on the gum”
Origin	Pluripotent basal cells in surface epithelium and adnexal structures	Basal cells in surface epithelium or dental lamina rests
Microscopic features	Budding of epithelial islands into lamina propria Prominent retraction artifact Scattered mitotic figures Apoptotic cells Mucoid ground substance Widely infiltrative throughout connective tissue Peripheral palisading but lacking apical vacuolization & reverse polarity	May or may not have connection to surface epithelium Little or no retraction artifact Few to absent mitotic figures Mucoid ground substance Not significantly infiltrative Islands of hyperchromatic basaloid cells with peripheral palisading, areas of stellate reticulum, prominent reverse polarity & apical vacuolization
Immunohistochemistry	Positive Ber-EP4; Negative for EMA and Calretinin	Negative Ber-EP4; Positive EMA and Calretinin

EMA epithelial membrane antigen