Breast ductal carcinoma and metastatic lymphoma to the contralateral breast in patient with cutaneous non-Hodgkin lymphoma.

Breast lymphoma is a rare condition, both as a primary and a metastatic manifestation. The primary form has an incidence ranging from 0.04% to 0.5% of all breast neoplasms, whereas the metastatic form has an incidence of 0.07%. We hereby report a clinical case of a patient who presented with cutaneous non-Hodgkin lymphoma (NHL) in the left scapulohumeral region treated with surgery followed by radiotherapy (40 Gy total). Three years following radiotherapy, the patient was diagnosed with a left breast infiltrating ductal carcinoma, treated with conservative surgery and adjuvant therapy. The following year, i.e. four years after the initial diagnosis of NHL, two lymphoproliferative relapses occurred: in the left cutaneous scapulohumeral region at the original site of disease, and in the right breast. The aim of this paper is to highlight an uncommon oncologic disorder such as breast lymphoma, highlighting its clinical and radiological manifestations. Some studies reported a possible aetiological role of radiotherapy in the development of breast cancer following treatment of NHL, and in the development of breast cancer following treatment of Hodgkin lymphoma, which could potentially explain our findings.