Non-Hodgkin lymphomas of the breast are rare, encompassing approximately 0.04-0.5% of all malignant breast tumors, and the vast majority are B-cell lymphomas. In contrast, lymphomas of T-cell phenotype have been rarely reported and some of these have been in close proximity to a breast implant. In our consultation practice, we have identified four patients with primary T-cell anaplastic large-cell lymphoma presenting adjacent to silicone or saline breast implants. All patients presented with seroma and neoplastic cells were identified in suspension in the serous fluid without solid tissue invasion. Three patients had no evidence of systemic disease (stage 1E), and one patient was not staged. The mean age of the patients was 46 years (range, 34-59 years). In all patients, the neoplastic cells had a T-cell phenotype, expressed CD30, cytotoxic granule-associated proteins, EMA and clusterin, and were anaplastic lymphoma kinase-1-negative. Clonal T-cell receptor gamma-chain gene rearrangements were identified in three patients. All patients underwent capsulectomy with removal of the implant. One patient subsequently received chemotherapy and radiation therapy, and another was treated with radiation alone. The third patient received no further therapy and the fourth patient has been recently diagnosed. After a mean time of 13 months (range, 9-20 months), all three patients with follow-up were alive and well without any recurrence or systemic disease. Although the follow-up time was relatively short, our series and other reported cases suggest that primary anaplastic large-cell lymphoma adjacent to breast implants is an indolent T-cell lymphoproliferative disorder.