Syphilitic Aortitis: 18F-FDG PET/CT Detection – Cureus
- Syphilis, a sexually transmitted infection, is often thought of in terms of initial sores and rashes.
- traditionally, diagnosing syphilitic aortitis requires a high degree of clinical suspicion and often involves invasive procedures like biopsies.
- A 68-year-old man underwent an 18F-FDG PET/CT scan for evaluation of a suspected recurrence of lung cancer.
Unexpected Heart Scan Finding Leads to Syphilis diagnosis
Table of Contents
Published October 12, 2025
The Silent Threat of Syphilitic Aortitis
Syphilis, a sexually transmitted infection, is often thought of in terms of initial sores and rashes. However, if left untreated, it can progress to a much more serious condition called syphilitic aortitis – inflammation of the aorta, the body’s largest artery. This can lead to life-threatening complications like aneurysms, aortic valve disease, and even rupture.
traditionally, diagnosing syphilitic aortitis requires a high degree of clinical suspicion and often involves invasive procedures like biopsies. But a recent case highlights the potential of a non-invasive imaging technique,Fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT),to detect this condition incidentally.
A 68-year-old man underwent an 18F-FDG PET/CT scan for evaluation of a suspected recurrence of lung cancer. During the scan, radiologists noticed unexpected and intense uptake of the radioactive tracer in the ascending aorta – the section of the aorta that emerges from the heart. This heightened activity suggested inflammation.Further investigation, including a Venereal Disease Research Laboratory (VDRL) blood test, confirmed a diagnosis of syphilis.
The patient had no prior known history of syphilis and reported no symptoms directly attributable to the infection. The PET/CT scan, initially intended for cancer staging, unexpectedly revealed the underlying cause of the aortic inflammation. The scan showed significant FDG avidity extending from the aortic root to the ascending aorta, indicating active inflammation.
The Role of 18F-FDG PET/CT in Diagnosis
18F-FDG PET/CT scans work by detecting areas of increased metabolic activity, which frequently enough corresponds to inflammation or cancerous growth. in this case, the inflammation caused by syphilitic aortitis was readily visible on the scan. While not a primary diagnostic tool for syphilis, this case demonstrates its potential to identify aortitis in patients undergoing scans for other reasons.
The patient was afterward treated with penicillin, the standard antibiotic for syphilis. Follow-up evaluations are planned to monitor his response to treatment and assess the resolution of the aortic inflammation. The case underscores the importance of considering syphilis in the differential diagnosis of aortic inflammation, even in the absence of typical symptoms.
Implications for Patient Care
This finding has important implications for healthcare providers. It suggests that 18F-FDG PET/CT scans, routinely used in oncology and other fields, could serve as an early detection method for syphilitic aortitis, potentially preventing serious cardiovascular complications. Early diagnosis and treatment of syphilis are crucial to prevent progression to aortitis and its associated risks.
While further research is needed to determine the sensitivity and specificity of 18F-FDG PET/CT for detecting syphilitic aortitis, this case provides a compelling example of how incidental findings on imaging scans can lead to life-saving diagnoses. Patients undergoing PET/CT scans should discuss any unexpected findings with their healthcare team to ensure appropriate follow-up and management.