Clinical History
A young woman without significant past medical history presented to the emergency department with persistent fever (38.5°C) and associated painful, tender right cervical and supraclavicular swelling.
Eight days earlier she manifested sore throat accompanied by high fever and shivers, interpreted as pharyngo-tonsillitis and treated with oral antibiotics by the family physician.
Imaging Findings
Physically, she appeared pale, tachycardic, with stable vital signs, and right upper arm mild cyanosis. She denied trauma, drug and medication (including contraceptive pill) use. ENT endoscopy did not disclose acute findings.
Laboratory revealed mild leukocytosis, markedly increased C-reactive protein (252 mg/L), normal venous blood gases.
Urgent contrast-enhanced multidetector CT of the neck and thorax, requested to investigate clinical suspicion of cervical abscess, disclosed acute occlusive thrombophlebitis of the right internal jugular vein (Fig. 1) consistent with early Lemierre syndrome. Coexistent infectious adenopathies, deep cervical abscesses, and septic lung embolisation were excluded.
Intravenous antibiotic treatment plus low-molecular weight heparin anticoagulation was started. Initial treatment response was observed on follow-up CT ten days later (Fig. 2).
Regression of symptoms, laboratory abnormalities, and IJV thrombosis at colour Doppler ultrasound (not shown) was achieved after three weeks. Serology including cytomegalovirus, toxoplasma, Epstein-Barr and Human Immunodeficiency viruses, and thrombophilic screening yielded negative results.
Discussion
Lemierre syndrome (LS) involves septic thrombophlebitis of the internal jugular vein (IJV) following an oropharyngeal infection, with subsequent metastatic dissemination. Although exceptional compared to the preantibiotic era, LS is encountered nowadays due to decreased tonsillectomy rates and antibiotics use for respiratory infections. The anaerobic Gram-negative rod Fusobacterium necrophorum, found in the normal oropharyngeal flora, is the most common causative organism. Infection invades the deep neck spaces from a primary oropharyngeal infection, through venous or lymphatic channels, to cause ipsilateral IJV septic thrombophlebitis [1-4].
The majority of cases occur in previously healthy young individuals, and manifest with neck pain, tenderness and/or swelling 3-10 days after a febrile sore throat. Laboratory signs of infection include leukocytosis, elevated C-reactive protein, mild thrombocytopenia. Unfortunately, clinical features are potentially confusing, and clinicians are unfamiliar with this uncommon, potentially life-threatening entity. Alternatively cervical abscess, inflammatory lymphadenopathy, or septic sterno-clavicular arthritis are usually suspected [1, 2, 4].
A helpful first-line investigation without radiation and contrast medium use, colour Doppler ultrasound (CDUS) detects most gross thrombi in distended, noncompressible veins with absent flow, although with limitations in areas behind the clavicle and toward the skull base [3, 4].
Contrast-enhanced multidetector CT is the preferred modality to investigate suspected deep cervical and vascular infections, and can effectively demonstrate occlusive and non-occlusive thrombophlebitis. Typical findings include IJV distension with thickened enhancing walls, hypoattenuating opacification defects, associated oedema of the surrounding soft tissues. Preliminary unenhanced acquisition is recommended, since vessel hyperattenuation due to increased haemoglobin concentration indicates an acute clot. Multiplanar reformations show the extent of the IJV thrombosis, additional thrombi in the retromandibular, facial, or external jugular veins, underlying pharyngeal or cervical abscesses. Alternatively, septic jugular thrombophlebitis may be caused by bacteraemia secondary to intravenous drug use, indwelling catheters or cardiac valvular disease [3-6].
In conclusion, LS should be suspected in healthy young patients with fever and neck pain after oropharyngeal infections, and imaging is crucial to provide a timely diagnosis. When CT or CDUS detect IJV thrombophlebitis, aggressive antibiotic therapy with anaerobic activity should be started even with negative or unavailable blood cultures [1-4]. Promptly recognised and treated with antibiotics plus anticoagulation, LS has a good prognosis in over 90% of patients. Surgical IJV excision or ligation is reserved for the few unresponsive cases. Conversely, an unrecognised infection may spread haematogenously, particularly to the lungs (80% of patients), sometimes to the joints, liver, heart, brain, or kidney [1-3, 7].
Differential Diagnosis List
Septic jugular vein thrombophlebitis (Lemierre syndrome)
Aseptic venous thrombosis
Deep cervical abscess
Infectious adenopathies
Suppurative thyroiditis
Septic sterno-clavicular arthritis
Intravenous drug abuse
Final Diagnosis
Septic jugular vein thrombophlebitis (Lemierre syndrome)
