Persistent Elevation of β-hCG Levels in a Patient with Primary Malignant Giant Cell Tumor of Bone: a Case Report and Literature Review.

BACKGROUND

Beta-human chorionic gonadotropin (β-hCG) is commonly used in pregnancy detection and as a tumor marker for reproductive system cancers.

METHODS

We report a case of a 51-year-old female with primary malignant giant cell tumor of bone (MGCTB) who developed persistently elevated serum β-hCG levels. Considering the possibility of detection interference, we evaluated pre-analytical factors, laboratory quality control, instrumentation, and personnel-related issues, and performed polyethylene glycol precipitation testing to exclude endogenous interference.

RESULTS

No interfering factors affecting the β-hCG results were identified, and the measured β-hCG levels were confirmed to be accurate and reliable. The patient was diagnosed with MGCTB, a rare mesenchymal tumor. Eight months after undergoing tumor resection and chemotherapy, she developed pulmonary metastases. During hospitalization, progressive increases in C-reactive protein, D-dimer, and β-hCG levels were observed. We conducted a literature review on mesenchymal tumors with aberrant β-hCG expression, which indicated that elevated β-hCG levels may be associated with poor prognosis.

CONCLUSIONS

This case suggests that MGCTB may be an unrecognized source of ectopic β-hCG secretion. Clini-cians should consider this possibility in similar contexts to avoid misdiagnosis and unnecessary interventions.