Syphilitic Aneurysm - Erler Zimmer
Clinical History
A 61-year-old man presents with exertional anginal chest pain and dyspnoea persisting for six years, gradually worsening in severity. During examination, he exhibits cyanosis, tachycardia with a collapsing pulse, and a notable swelling on the right side of his neck. Additionally, a thrill is observed in his carotid artery, and the apex beat is displaced inferolaterally. Auscultation reveals a loud systolic and diastolic murmur in the aortic area. Chest X-rays indicate cardiomegaly with a large rounded lesion in the right upper mediastinum, continuous with the heart shadow, presenting radiographic evidence of cardiac failure. Blood tests confirm positive results for anti-treponemal antibodies. Unfortunately, the patient's condition deteriorates, leading to death from cardiac failure.
Pathology
The specimen comprises the patient's enlarged heart, encompassing the aortic arch and descending aorta. The ascending aorta exhibits dilation up to 7 cm in diameter, expanding superiorly with a large aneurysmal bulge measuring 11 x 13 cm. This has been opened to reveal the wrinkled, scarred intimal surface, with marked atheroma of the intima. The innominate, left common carotid, and subclavian arteries have been displaced towards the patient's left by the aneurysm. On the internal surface of the aneurysm, a ridge-like thickening 5 mm high is observed, representing the site of attachment of the pericardial sac externally. The adventitia of the aorta shows significant congestion of small blood vessels. This pathology is indicative of a syphilitic aneurysm of the arch of the aorta.
Further Information
Syphilis, caused by the spirochete Treponema pallidum, is a chronic infection. While primarily transmitted sexually, congenital acquisition is also possible through transplacental transmission. Those at higher risk include those of a sexually active age, intravenous drug users, HIV-infected individuals, and males in same-sex relationships. Although syphilis infection rates decreased significantly with the introduction of penicillin in 1943, there has been an increase since the early 2000s.
Syphilis is categorized into three clinical stages, each presenting distinct clinical and pathological features characterized by proliferative endarteritis affecting small vessels.
Primary syphilis typically manifests three weeks after initial infection, presenting as a single, painless, erythematous lesion known as a chancre. The syphilis then disseminates throughout the body, with the chancre healing spontaneously after 3 to 6 weeks.
Secondary syphilis occurs weeks to months after the resolution of the primary chancre in 75% of untreated patients. During this stage, patients commonly experience generalized symptoms such as malaise, lymphadenopathy, and skin rashes. Palmar/plantar rashes are common, and these rashes can be maculopapular, scaly, or pustular.
Condylomata lata, elevated gray plaques, arise on moist mucous membranes, and less common manifestations include hepatitis, gastrointestinal invasion or ulceration, and neurosyphilis. Tertiary syphilis has three main characteristics: cardiovascular syphilis, neurosyphilis, and gummatous syphilis. These manifest after a latent period of 5 years or more in a significant portion of untreated patients.
Cardiovascular syphilis involves aortitis, with the vasculitis affecting the ascending thoracic aorta, leading to progressive dilation of the aortic root. This can result in aortic valve insufficiency from the dilation of the aortic valve ring. Endarteritis of the vasa vasorum leads to scarring of the media, causing the formation of aneurysms. Clinical manifestations typically occur 15-30 years post-initial infection.
Neurosyphilis can be symptomatic or asymptomatic, occurring in 10% of untreated patients. Early clinical manifestations include headaches, meningitis, hearing loss, and ocular involvement, commonly uveitis, causing vision loss. Late manifestations can occur up to 25 years post-initial infection, with main features being meningovascular neurosyphilis, paretic neurosyphilis, and tabes dorsalis. Meningovascular involvement leads to chronic meningitis and endarteritis, potentially resulting in strokes. Tabes dorsalis arises from degeneration of the posterior columns within the spinal cord, causing loss of proprioception, ataxia, loss of pain sensation, and loss of reflexes. Paretic neurosyphilis is caused by invasion and damage of the brain parenchyma, typically the frontal lobes, leading to progressive cognitive impairment and mood disturbance.
Gummatous syphilis is characterized by the formation of nodular lesions, most commonly in bone, skin, and mucosa of the upper airway and mouth, known as gummas. These lesions can occur anywhere, including viscera. Although the formation of gummas is rare, it occurs more frequently in HIV-infected patients. Skeletal involvement can cause pain and pathological fractures.
