13. Intraductal squamous carcinoma
Intraductal squamous carcinoma with typical centrifugal growth of ducts which may form extensive keratinized masses. These tumors can be induced with DMBA or are found in mouse strains carrying MMTV-P (eg, RIII, GR). These tumors could be mistaken for skin tumors. Also referred to as 'adenoacanthoma, molluscoid form'