An Unusual Case of Metastatic Pregnancy-associated Breast Cancer: Challenges in Diagnosis and Management

Introduction: Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during pregnancy or within 1 year postpartum.Diagnostic challenges arise due to physiological changes in the breast during pregnancy and lactation.Case description: We present an unusual case of metastatic PABC in a 35-year-old G3P2L1 with a history of prior fetal demise who presented at 29 weeks of gestation with recurring right breast invasive ductal carcinoma.The patient, after multidisciplinary counseling, opted for preterm delivery at 30 weeks and 5 days gestation followed by a postpartum positron emission tomography-computed tomography (PET-CT) scan which revealed metastasis to the lungs and bones and started with immediate anthracycline-based chemotherapy.Serial PET-CT scans showed a partial response after four cycles, followed by tamoxifen maintenance after completing a total of six cycles.Conclusion: This case highlights the complexities of managing PABC, emphasizing the critical role of diagnosing this case, shared decisionmaking, and multidisciplinary coordination to optimize both maternal and fetal outcomes.It also illustrates the importance of considering patient autonomy, especially in complex, metastatic presentations.