Management of lobular carcinoma in situ and ductal carcinoma in situ of the breast.

Mammographic screening has resulted in an epidemic of diagnoses of ductal carcinoma in situ (DCIS). These are often small, impalpable lesions that do not reflect the natural history of older series of DCIS found by palpation at a larger size. The behavior of DCIS is related to the histological grade and size of the tumor. Therapy is primarily surgical excision. Irradiation has been shown to halve the rate of recurrence after local excision. Therapeutic decisions involving the extent of surgical excision and the addition of irradiation are based on considerations of tumor size and grade and the patient's age.