Persistently elevated hCG in a patient with no clear evidence of pregnancy

Background We describe a case of a female patient with a complex medical history, including squamous cell carcinoma of the tongue, and persistent elevation in serum hCG and no confirmed intrauterine or extrauterine pregnancy. Methods The clinical chemistry laboratory was called upon to help clarify the situation and reach a diagnosis. Results Multiple potential sources of elevated hCG were considered and excluded. Conclusions This case shows a rare example of paraneoplastic hCG expression and highlights the role of the clinical chemistry laboratory in resolving diagnostic dilemmas and interpreting laboratory results in patients with multiple medical comorbidities.