Human chorionic gonadotropin-secreting osteosarcoma.

Secretion of beta human chorionic gonadotropin (β-hCG) is a rare, recently recognised paraneoplastic syndrome. Herein, we present a case of a woman in her 30s with right femur conventional high-grade osteosarcoma and a positive screening urine pregnancy test. Subsequent workup failed to reveal an intrauterine or extrauterine pregnancy. Rather, pathology and gene expression studies confirmed serum β-hCG production by osteosarcoma cells. Though the prognostic implications of β-hCG expression are unclear, β-hCG may be a useful surveillance marker to monitor disease progression or recurrence.