Unsuspected syphilitic hepatitis in a patient with low-grade proteinuria and abnormal liver function A 25-year-old patient was found to have cholestatic liver enzyme abnormalities during assessment for asymptomatic low-grade proteinuria at the US Naval Hospital in Portsmouth, Virginia. These abnormalities persisted for a 6-month period, and an extensive workup, including viral serologic studies, rapid plasma reagin test, iron studies, ceruloplasmin, antimitochondrial, antinuclear, and anti-human immunodeficiency virus antibodies, endoscopic retrograde cholangiopancreatography, and liver biopsy, was unrevealing until serologic tests for syphilis were repeated to evaluate a new onset of urethral discharge. The patient had none of the more characteristic signs of secondary syphilis. The liver enzyme abnormalities rapidly resolved after treatment with penicillin. Syphilis remains the great impostor and still must be considered in the differential diagnosis of unexplained liver enzyme abnormalities, even in a patient with no symptoms or signs of early syphilis. 