Elevated Serum βhCG in a 34-Year-Old Woman with Breast Cancer

A 34-year-old G5P4014 (5 pregnancies, 4 children born at term, 0 preterm, 1 abortion, and 4 living children) with stage IV triple-positive (ER+/PR+/Her2+) breast cancer was admitted to the medical oncology service for recurrent shortness of breath and right-sided pleuritic chest pain secondary to disease progression. The patient had widespread metastases to the bone, liver, and lungs and was being treated with docetaxel, trastuzumab, pertuzumab, and zoledronic acid. A gynecology consult was requested after the patient was incidentally noted to have a positive urine human chorionic gonadotropin (hCG)4 (Beckman Coulter Icon 25) and serum βhCG of 102 mIU/mL (Beckman UniCel® DxI). There was no evidence of impaired renal function (estimated glomerular filtration rate levels all within normal limits), and no medications that can affect hCG concentration were noted in the patient's chart. The patient's last menstrual period was approximately 1 year ago. She experienced premature ovarian failure because of chemotoxic effects on the ovary. The patient last had unprotected sexual intercourse about 6 months before her presentation. She complained of chronic lower back pain and nausea, which were attributed to chemotherapy, but denied having any vaginal bleeding, spotting, lower abdominal pain, or cramping. There was no evidence of an intrauterine or ectopic pregnancy seen on transvaginal ultrasound. The βhCG …