Purpose: A high serum level of beta human chorionic gonadotropin (hCG) normally indicates pregnancy in healthy women. We were confused by this finding in one of our patients. This 18-year-old girl presented with amenorrhoea of 1-month duration, a positive pregnancy test and a high beta-hCG serum level although taking contraceptives. Pregnancy was excluded by ultrasound. Three years previously, she had had an osteosarcoma of the humerus. The tumour initially had been wide resected and had shown a good response to neoadjuvant chemotherapy with COSS-96-protocol.
Methods: We reviewed the original histological result and the literature about possible similar findings. We analysed therapeutic options and the value of beta-hCG levels as a therapy monitor.
Results: During examination we detected a recurrent osteosarcoma of the left humerus. The local relapse evidently expressed beta-hCG which, retrospectively, could only sparsely be shown in the primary resectate. After intralesional surgery, chemotherapy and radiotherapy levels of beta-hCG normalised.
Conclusion: Osteosarcoma very rarely is able to produce a paraneoplastic syndrome by high levels of beta-hCG. This may well be of diagnostic value and offer an additional monitoring tool. It can indicate tumour recurrence and dedifferentiation.