Differential Diagnosis for High hCG in a Non-Pregnant Woman

Single Most Likely Diagnosis

• Pituitary hCG production: This is often seen in women with pituitary disorders, where the pituitary gland produces hCG, leading to elevated levels. This condition is relatively common and should be considered first due to its frequency and the fact that hCG can be produced by the pituitary gland in non-pregnant states.

Other Likely Diagnoses

• Germ cell tumors: Certain types of germ cell tumors, such as choriocarcinoma, can produce hCG. These tumors are more common in younger women and can cause significantly elevated hCG levels.
• Trophoblastic disease: Although rare, trophoblastic disease (including hydatidiform mole) can occur in non-pregnant women, especially if there has been a recent pregnancy or miscarriage.
• Phantom hCG: This is a false-positive result due to the presence of heterophile antibodies that interfere with hCG assays, leading to elevated readings.

Do Not Miss Diagnoses

• Choriocarcinoma: A type of cancer that can produce hCG, often presenting with high levels. Missing this diagnosis could lead to delayed treatment and poor outcomes.
• Testicular cancer in a trans man or non-binary individual: Certain types of testicular cancer can produce hCG, and it's crucial not to miss this diagnosis due to the potential for severe consequences if left untreated.

Rare Diagnoses

• Hepatoblastoma or other rare tumors: Some rare tumors, such as hepatoblastoma, can produce hCG, leading to elevated levels in non-pregnant women.
• Familial hCG syndrome: A rare genetic condition where individuals have persistently elevated hCG levels without any underlying pathology.
• hCG-producing lung cancer: Certain types of lung cancer can produce hCG, although this is extremely rare and usually seen in advanced stages of the disease.