Syphilitic aneurysms commonly occur in ascending aorta (50%),
aortic arch (30%), descending aorta (15%) and abdominal aorta in 5%.
Most aneurysms are saccular and less commonly fusiform. [3]
The diagnosis of tertiary syphilis may be difficult because
clinical features may be similar with other granulomatous disease and
serologic titers specially the nontreponemal one could be low or
negative [10, 11]. The approach of using treponomal test as
screening test, first described in 2008 by the US CDC is gaining
popularity because it can detect syphilis in some patients with syphilis
who would not have been identified if a nontreponemal test was used
initially. However, it results in higher rate of false positivity as
well. [12, 13] To settle the diagnosis of confirmed cardiovascular
tertiary syphilis, on top of a clinically compatible case it requires
either identification of treponemes in tissue sections with silver or
immunohistochemical staining or detection of T. palladium DNA in
tissue with PCR. Our patient had positive serologic tests in the
background of an abdominal aneurysm and no classic risk factors for
atherosclerotic aneurysm like diabetes, hypertension or obesity which
makes syphilitic aneurysm highly likely. [14] A possible limitation
is that we did not have a histologic confirmation which may not be
mandatory since mesoaortitis by itself is not diagnostic in the absence
of serology. [15] Many case reports clinically diagnosed syphilitic
aneurysm with an appropriate clinical presentation and high serum TPHA.
[14, 16]
Cardiovascular syphilis left untreated it can lead to rupture of
aneurysm, coronary ostial necrosis with sudden death and embolization.
[3] Treatment of syphilitic AAA involves medical treatment with
intramuscular penicillin and surgical intervention. Symptomatic AAA
(abdominal, back, flank pain and limb ischemia) has increased risk of
aneurysmal rupture, hence most require repair. Urgent or emergent repair
is indicated for patients with ruptured AAA and symptomatic non ruptured
AAA, provided the risk of repair is not prohibitive. [17, 18]
Conclusion