the incidence of cardiovascular syphilis ( cvs ) in cases of late untreated syphilis is 10% . three main categories of cvs syphilisare syphilis of heart , great vessels , and medium - sized arteries . aortic involvement by syphilis can present as uncomplicated aortitis , coronary ostial stenosis , aortic regurgitation , and aortic aneurysm . ascending aorta is the most common segment affected ( 50% ) followed by arch ( 35% ) and descending aorta ( 15% ) . although a few cases of syphilitic aneurysm have been reported in developing countries , descending thoracic and upper abdominal aortic aneurysm due to syphilis is very rare and has not been reported in the past decade , to the best of our knowledge . here , we report this rare case of cvs syphilis complicated by lower thoracic and upper abdominal aortic aneurysm with dissection , peripheral thrombus formation , and erosion of vertebral body . a 50-year - old male , a known smoker and alcoholic , presented with complaints of left lower abdominal pain for past 10 days . pain was insidious in onset , gradually increased in severity , continuous , pricking type , and radiated to back and both shoulders . patient denies pre- and extra - marital contact . there was no history of hypertension , diabetes mellitus , atherosclerosis , coronary artery disease , and peripheral vascular disease in the past . on examination , genital and dermatological examination was normal and did not reveal any signs of syphilis . on investigation , hematological and biochemical parameters chest radiograph revealed blunting of cardiophrenic angle on the left side [ figure 1 ] . x - ray revealing blunting of left cardiophrenic angle contrast - enhanced computed tomography of the chest and abdomen revealed aneurysmal dilatation of lower thoracic and upper abdominal aorta from d9 to origin of coeliac trunk . dissection was noted in aorta at d9 to d12 level with false lumen showing peripheral thrombus and erosion of d12 vertebra [ figure 2 ] . contrast - enhanced computed tomography of the chest and abdomen revealed aneurysmal dilatation of lower thoracic and upper abdominal aorta from d9 to origin of coeliac trunk . dissection noted at d9 to d12 level with erosion of d12 thoracoabdominal aortogram revealed well - enhancing saccular outpouching having a broad neck seen arising from posterior wall of thoracoabdominal aorta . the neck is opposite to d11 and d12 vertebral bodies with lower border at the level of coeliac artery origin . the sac along with surrounding inflammatory tissue and hematoma was seen from d10 to d11 level . there is lytic destruction of anterior vertebral body and adjacent endplates of d10 and d11 vertebra with surrounding sclerosis and reduction in height of d11 vertebral body , erosion of d12 vertebra , and infected aneurysm of adjacent thoracoabdominal aorta [ figure 3 ] . thoracoabdominal aortogram revealed well - enhancing saccular outpouching having a broad neck seen arising from posterior wall of thoracoabdominal aorta serum venereal disease research laboratory test was positive in 1:4 dilution . patient treated with injection procaine penicillin 12 lakh units intramuscularly ( i m ) once daily after test dose for 20 days undercover of oral steroids . histopathology revealed elastic tissue degeneration of media and replacement with fibrous tissue , intima shows thinning . it is more common in men than in women . its incidence is higher in those whose occupation involves heavy physical work . the interval from infection to the first sign of the disease is 1040 years . at the time of diagnosis , reagin tests are positive in 90% cases . specific test is positive in nearly all cases . in this era of early use of highly effective antibiotics , aneurysm indicates marked degree of dilatation of aorta . the swelling may be fusiform or saccular in shape . a saccular aneurysm may be connected to the aorta by a broad or narrow orifice . symptoms of deep - seated and continuous pain in the back , boring in character , may result from pressure on the body of thoracic vertebrae . patient may complain of pain in the abdomen or back , worse at night , but relieved by change in position . it is prudent to rule out neurosyphilis in all cases of cvs syphilis as concomitant infection is found in 43% of cases . definitive treatment of aneurysm includes surgical treatment which involves resection of dilated portion of aorta and replacing with synthetic vascular grafts . medical treatment of cvs syphilis includes injection benzathine penicillin - g 2.4 million units i m weekly once for 3 weeks . alternatively , procaine penicillin 12 lakh units i m for 20 days can be used . in penicillin - allergic patients other drugs include tetracycline 500 mg 4 times a day for 30 days , erythromycin 500 mg 4 times a day for 30 days , and doxycycline 200 mg daily for 30 days . this is a case of descending thoracic and upper abdominal aortic aneurysm due to syphilis with dissection and thrombus formation . this case is being presented for its rarity as cvs syphilis itself is a rare manifestation in this era of early usage of antibiotics and , in this case , descending thoracic and upper abdominal aortic aneurysm due to syphilis is rarer .
a 50-year - old male presented with left lower abdominal pain , visible pulsation below xiphoid process , and tenderness in the left iliac fossa for the past 10 days . 
 chest x - ray revealed blunting of left cardiophrenic angle . 
 echocardiogram revealed descending thoracic aortic pseudoaneurysm . 
 contrast - enhanced computed tomography of the chest and abdomen revealed dissecting aneurysm of lower thoracic and upper abdominal aorta . 
 thoracoabdominal aortogram revealed erosion of d12 vertebra and infected aneurysm of adjacent thoracoabdominal aorta . 
 serum venereal disease research laboratory assay was positive in 1:4 dilution treponema pallidum hemagglutination assay was positive . 
 the patient was treated with injection procaine penicillin for 20 days undercover of steroids . 
 cerebrospinal fluid analysis was normal . 
 aortic aneurysm repair with reconstruction was done . 
 histopathology was in favor of syphilitic etiology . 
 this case is being presented as descending thoracic and upper abdominal aortic aneurysm due to syphilis complicated by dissection and erosion of vertebral body is rare and has not been reported nowadays to the best of our knowledge .