Abstract
BACKGROUND: The liver is the most common site of digestive system tumor metastasis, but not all liver metastases can be traced back to the primary lesions. Although it is unusual, syphilis can impact the liver, manifesting as syphilitic hepatitis with inflammatory nodules, which might be misdiagnosed as metastasis. CASE SUMMARY: This case report involves a 46-year-old female who developed right upper abdominal pain and intermittent low fever that persisted for more than three months. No definitive diagnosis of a tumor had been made in the past decades, but signs of multiple liver metastases were recognized after a computed tomography scan without evidence of primary lesions. With positive serological tests for syphilis and a biopsy of the liver nodules, a diagnosis of hepatic syphilis was made and confirmed with follow-up nodule reduction after anti-syphilis therapy. CONCLUSION: Clinicians must be aware of the possibility that syphilis can cause hepatic inflammatory masses, especially when liver metastasis is suspected without evidence of primary lesions. A definitive diagnosis should be established in conjunction with a review of the patient's medical history for accurate therapeutic intervention.