Concurrent invasive ductal carcinoma of the breast and malignant follicular lymphoma, initially suspected to be metastatic breast cancer: a case report.

This report describes a case of a 40-year-old female patient with concurrent invasive ductal carcinoma of the breast and malignant follicular lymphoma, initially suspected to be metastatic breast cancer. During the initial evaluation of invasive ductal carcinoma of right breast, multiple lymphadenopathies were noted throughout the body on ultrasonography and positron emission tomography/computed tomography images. Clinically, metastatic breast cancer was suggested, and the patient was administered chemotherapy, including hormonal therapy. The breast cancer improved slightly, but the lymphadenopathies progressed and excisional biopsy of a cervical lymph node revealed malignant follicular lymphoma.