Background: The production of human chorionic gonadotropin (hCG) can be stimulated by both pregnancy and malignancy.
Methods: Two patients with increased serum hCG and a retroperitoneal mass were monitored throughout the course of disease to evaluate fluctuations in hCG concentrations. Pathologic examination was performed on the resection specimens.
Results: The retroperitoneal masses were identified as a benign epidermoid cyst and pancreatic ductal adenocarcinoma. The serum hCG concentration of the patient with the splenic epidermiod cyst decreased upon resection of the mass, and immunohistochemical staining demonstrated that the cyst lining expressed hCG. This is the first report of hCG secretion by an epidermoid cyst. The serum hCG concentrations of the patient with pancreatic adenocarcinoma paralleled the secretion of cancer antigen 19-9 and reflected the course of disease progression. Additional testing suggested that a different form of hCG was produced by each neoplasm.
Conclusions: hCG secretion may be associated with both benign and malignant neoplasms. Laboratory testing can be utilized to further characterize increased serum hCG, and may help to determine the etiology of the increased hCG.