Malignant pericardial effusion 7 years after treatment of ductal carcinoma in situ of breast

Ductal carcinoma in situ (DCIS) is a precursor of invasive breast cancer (IBC) that may or may not lead to IBC. Although the incidence is increasing, it usually has a good prognosis. Local recurrence can occur in the form of DCIS or IBC. Distant metastasis is uncommon and in the absence of local recurrence is extremely rare. Here, we report a case of a 47-year-old female with DCIS, who, 7 years after treatment developed malignant pericardial effusion along with lung and marrow metastasis. This is the second reported case of distant multiple metastases without local recurrence in a known case of DCIS. This shows the possibility of aggressive behavior in DCIS that usually has a favorable prognosis.