A 59-year-old woman with a history of cosmetic implants developed ipsilateral synchronous breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) and invasive ductal carcinoma in the left breast. Each tumor was subjected to next-generation sequencing, and separate analyses revealed mutually exclusive aberrations: an activating STAT3 mutation in the lymphoma and a PIK3CA in-frame deletion in the carcinoma. The patient was treated with removal of implants, capsulectomy, partial mastectomy, sentinel node biopsy, radiotherapy, and endocrine therapy with no evidence of recurrence for 1 year. This case illustrates the importance of obtaining thorough evaluation for concomitant malignancies in the breast at the time of diagnosis of BIA-ALCL. Herein, we review the current recommendations for evaluation and management of BIA-ALCL.