Anti-phospholipid Antibody syndrome [APS] is now recognized as an important cause of hypercoagulability [1],[2]. Patients with APS who do not have an associated systemic disease are labeled as primary APS while those who have associated SLE or other connective tissue disease have secondary APS. The majority of patients are recognized after a venous (71%) or a less prevalent arterial thrombotic event, with pregnancy loss and thrombocytopenia being other presentations [3].

 

Fig. 1

SVC gram shows extensive thrombosis involving the right brachiocephalic and subclavian veins.

Fig. 2

CT show a Lacunar infarct in the region of the right internal capsule with a larger infarct involving the left external capsule.

A forty-year-old man presented with pain over the left shoulder and the arm, associated with swelling. Examination revealed dilated veins over the chest wall and neck suggesting the possibility of obstruction of the great veins of the thorax. The plain chest radiograph showed only a dilated and atheromatous aorta. A venogram of the superior vena cava (SVC) was performed and revealed multiple radiolucent areas, suggestive of thrombi, extending along the left brachiocephalic and left subclavian veins with collaterals seen over the left side of the chest wall and the neck (Fig.1).

The right brachiocephalic vein and SVC were spared. Following this, a contrast enhanced CT of the chest was performed, which in addition to the findings on the SVC venogram showed a dilated descending thoracic aorta. Further contiguous sections through the upper abdomen revealed dilatation of the abdominal aorta (reaching a maximum size of 4.1 cm) with wall calcification and extensive hypodense intraluminal thrombosis (Fig 2).

These findings of extensive thrombosis involving major veins of the thorax unilaterally associated with arterial thrombosis and premature atheroma led us to suspect hypercoagulability as a cause [4]. Detailed investigations relevant to the cause included a coagulation profile, which showed that the partial thromboplastin time (PTT) was characteristically prolonged. Serology for titres of anti-nuclear antibodies (ANA) and anti-phospholipid antibodies showed negative results for ANA, but strongly positive results (IgG -55 gml units/ml, IgM-22 mml units/ml) for anti-phospholipid antibodies, thereby confirming the diagnosis of APS [5].

 

Fig. 3

CECT shows a dilated abdominal aorta with hypodense intraluminal thrombus and wall calcification

A careful search for some of the other manifestations of APS showed that the patient had a chronic ulcer on his left leg with pain and swelling. A peripheral venogram showed evidence of thrombosis of the posterior tibial vein. As the patient also gave a history of weakness involving the left upper and lower limbs, a CT scan of the brain was performed which demonstrated lacunar infarcts in the right hemisphere (Fig. 3). The prevalence of cerebral thrombosis in APS is reported to be higher (25%) as compared to peripheral arterial thrombosis, while embolic strokes secondary to valvular vegetations are also frequent [5],[6]. The diagnostic possibility of APS should be kept in mind while imaging ischemic strokes with evidence of other thrombotic manifestations. In addition to these findings, echocardiography of the patient showed features of mild aortic stenosis, probably of atherosclerotic origin.

Cross-reaction between anti-phospholipid antibodies and oxidized LDL antibodies has been postulated as a cause of accentuated atheromas in APS [7]. The other manifestations of APS include cutaneous features (ulcers, livido reticularis, thrombophlebitis), cardiac (mitral incompetence, valvular vegetations), Budd-Chiari syndrome, renal vein thrombosis, pulmonary emboli, avascular necrosis of bone, multi-infarct dementia and intra-uterine growth retardation, most of which are often encountered in imaging studies [1].

The imaging findings suggestive of extensive deep venous thrombosis associated with widespread arterial thrombosis with premature atheromas gave us a clue towards the diagnosis of this rare and interesting condition.