Syphilitic Bone Destruction on FDG PET/CT

Syphilis Mimicking Malignant Pulmonary Tumor With Nodal and Bone Metastasis on 18 F-FDG PET/CT

ABSTRACT

A 52-year-old man suffering left pleuritic pain underwent a chest CT showing a subpleural pulmonary nodule in the left upper lobe. Because of the possibility of a lung tumor, he was referred for 18 F-FDG PET/CT. The scan revealed FDG uptake in the pulmonary nodule, in an upper right paratracheal lymph node, and at 4 destructive bone lesions. Pathologic examination after pulmonary biopsy manifested only the presence of inflammatory cells. Further clinical history research proved risky sexual behavior with a positive syphilis serology test. A follow-up PET/CT 7 months after penicillin therapy showed a complete metabolic response of all the lesions.

Gummatous Syphilis Mimicking Malignant Bone Tumor on FDG PET/CT

A 47-year-old woman suffered worsening pain in the waist and numbness in the right thigh for 1 month. MRI was performed to determine the cause, which detected an osteolytic lesion in the T12 vertebral body, suggestive of possible bone metastasis. FDG PET/CT scan was undertaken to detect the primary tumor, which only showed the same isolated lesion in the T12 without any other abnormal hypermetabolic lesion. The pathology following vertebrectomy revealed granulomatous infection. The diagnosis of osseous syphilis was eventually made following a subsequent positive Treponema pallidum serological test.

Usefulness of Positron Emission Tomography in Patients with Syphilis: A Systematic Review of Observational Studies

Background:

Diagnosis of syphilis is difficult. Follow-up and therapy evaluation of syphilitic patients are poor. Little is known about positron emission tomography (PET) in syphilis. This review was to systematically review usefulness of PET for diagnosis, disease extent evaluation, follow-up, and treatment response assessment in patients with syphilis.

Methods:

We searched PubMed, EMBASE, SCOPUS, Cochrane Library, Web of Science, ClinicalTrials.gov, and three Chinese databases (SinoMed, Wanfang, and CNKI) for English and Chinese language articles from inception to September 2016. We also collected potentially relevant studies and reviews using a manual search. The search keywords included the combined text and MeSH terms “syphilis” and “positron emission tomography”. We included studies that reporting syphilis with a PET scan before and/or after antibiotic treatment. The diagnosis of syphilis was based on serological criteria or dark field microscopy. Outcomes include pre- and post-treatment PET scan, pre- and post-treatment computed tomography, and pre- and post-treatment magnetic resonance imaging. We excluded the articles not published in English or Chinese or not involving humans.

Results:

Of 258 identified articles, 34 observational studies were included. Thirty-three studies were single-patient case reports and one study was a small case series. All patients were adults. The mean age of patients was 48.3 ± 12.1 years. In primary syphilis, increased fluorodeoxyglucose (FDG) accumulation could be seen at the site of inoculation or in the regional lymph nodes. In secondary syphilis with lung, bone, gastrointestinal involvement, or generalized lymphadenopathy, increased FDG uptake was the most commonly detected changes. In tertiary syphilis, increased glucose metabolic activity, hypometabolic lesions, or normal glucose uptake might be seen on PET. There were five types of PET scans in neurosyphilis. A repeated PET scan after treatment revealed apparent or complete resolution of the asymmetry of radiotracer uptake.

Conclusion:

PET is helpful in targeting diagnostic interventions, characterizing disease extent, assessing nodal involvement, and treatment efficacy for syphilis.

Syphilis Masquerading As Mass Lesions: The Utility of Modern-Day Imaging and Molecular Sequencing in Clinical Diagnosis

Syphilis has been known to present in a myriad of symptoms throughout the ages, and until this day, the diagnosis remains elusive to the modern physician. We present 2 unusual cases of syphilis that posed diagnostic challenges even in the current era of new and advancing diagnostic tests.

A case of secondary syphilis involving tonsil, pulmonary, and multiple lymph nodes: 18F-FDG PET/CT findings

A 50-year-old man with general fatigue and weight loss underwent FDG PET/CT scan to detect possible occult malignancy. The images revealed abnormal FDG activity in the tonsils, right lung, and in the cervical, axillary, and inguinal lymph nodes. Lymphoma was initially suspected. However, pathologic examination after cervical lymph node biopsy revealed only reactive hyperplasia. Further examinations including serologic tests led to a diagnosis of secondary syphilis. A follow-up PET/CT scan after a 6-month benzylpenicillin therapy showed significant interval improvement.

Usefulness of (18)F-FDG PET/CT in disease extent and treatment response assessment in a patient with syphilitic aortitis

A 40-year-old man was admitted to our hospital for surgical treatment of aortic insufficiency and coronary ostial stenosis. Histopathology and serological tests revealed a syphilitic aortitis. F-FDG PET/CT was performed to assess the extent of aortitis, showing increased radiopharmaceutical uptake along the ascending aortic wall. A repeated FDG PET/CT after antibiotic therapy showed a markedly reduced uptake in the aortic wall, suggesting resolution of the infection according to clinical and serological data. This case highlights the usefulness of FDG PET/CT for the assessment of disease extent and treatment response in patients with syphilitic aortitis.