Extranodal NK/T-Cell Lymphoma, Nasal Type, Presenting as a Breast Mass.

Extranodal natural killer/T-cell lymphoma, nasal type, is a rare type of non-Hodgkin cell lymphoma endemic to East Asia and parts of Central and South America. In most cases, it is driven by Epstein-Barr virus infections, with a broad range of morphologic appearances, frequent necrosis, and angioinvasion. It is designated as NK/T reflecting uncertainty in its cellular origins. These tumors usually arise in the nasal region, typically presenting with symptoms of nasal obstruction, epistaxis, and/or a destructive mass involving the nose, sinuses, or palate. The treatment of patients with extranodal NK/T-cell lymphoma, nasal type, is largely determined by the extent of disease. Localized disease is usually treated with radiation and chemotherapy. The disseminated disease requires combination chemotherapy. This report describes the case of a 30-year-old Caucasian female presenting with a left breast mass of two months duration. Excisional biopsy was done, and the pathological exam confirmed the diagnosis of extranodal NK/T-cell lymphoma, nasal type. Our patient received a systemic combination chemotherapy with steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) regimen, resulting in a complete clinical and radiological remission. On the basis of our review of the literature, extranodal NK/T non-Hodgkin cell lymphoma, nasal type, presenting as a breast mass is very rare and very uncommon in the United States. Awareness of this occurrence may be valuable as this case may be a forerunner of additional similar cases developing in the future.