Metastatic unknown primary tumor presenting in pregnancy as multiple cerebral infarcts

Cancer presenting during pregnancy is a rare event. There are no reports of an unknown primary tumor presenting during pregnancy. A 35-year-old primigravida presented at 16 weeks’ gestation with multiple cerebral infarcts. After a negative workup she was discharged on anticoagulation therapy, only to return at 29 weeks with diffuse, metastatic cancer of unknown primary origin. After an elective 32-week delivery she received aggressive chemotherapy but ultimately died 5 months later. Malignancy should be included in the differential diagnosis of unusual, unexplained cases of thromboembolism in pregnancy.