Falsely positive specific human chorionic gonadotropin assays in patients with testicular tumors: conversion to negative with testosterone administration.

We report false elevations of serum human chorionic gonadotropin levels in 4 patients with testicular germ cell tumors. Elevated circulating luteinizing hormone levels that resulted from unilateral orchiectomy were responsible for the falsely positive human chorionic gonadotropin activity measured in commercial radioimmunoassays. In 3 patients tested aliquots of serum evaluated in reliable human chorionic gonadotropin assay systems revealed no elevation. We administered testosterone to 3 patients who had elevations of luteinizing hormone and human chorionic gonadotropin levels. Luteinizing hormone was suppress-d to normal levels 1 week later in 2 patients and in 1 it was diminished but still slightly elevated. In all 3 cases the falsely positive human chorionic gonadotropin results converted to negative. Recognition of falsely positive elevations of human chorionic gonadotropin can spare patients unnecessary operations and/or chemotherapy.