DCIS versus LCIS
DCIS is ductal carcinoma in situ. LCIS is lobular carcinoma in situ.
DCIS is considered a precursor lesion to invasive carcinoma whereas LCIS is considered a marker for increased risk of developing breast cancer.
DCIS is typically treated with surgery +/- radiation and LCIS is not.
The only exception to this is pleomorphic LCIS which is treated similarly to DCIS.