An uncommon etiology of infrarenal aortitis

A 61-year-old man presented to the emergency with deterioration of general condition, hypertension, pain and cramps in his legs for several months. Patient is known with nodal marginal zone B cell lymphomas (NMZLs).

Contrast-enhanced CT of the abdomen in venous phase shows a hypodense, homogeneous, circumferential and diffuse wall thickening of the infra-renal aorta (Figure 1), extending to the iliac arteries (Figure 2) and involving the lumbar segment of the left ureter, causing a significant left ureterohydronephrosis. Associated with multiple bilateral para-aortic, interaorticocaval and iliac lymphadenopathy.

Since the patient has a history of lymphoma, a FDG PET/CT was performed to assess inflammatory activity. It constitutes a valuable imaging modality to help establish the diagnosis, monitor disease progression and help for the identification of optimal target sites for biopsies [1,2].

The Positron Emission Tomography examination (PET) shows a moderately hypermetabolic infiltration of the aorta extending to the iliac arteries suggesting an inflammatory process [figure 3 a and b]. A biopsy of the peri-aortic tissue was performed and the histopathological examination showed infiltration by a Lymphoma Marginal Zone with a reduced degree of malignancy, CD5 +.

The findings described were considered compatible with an aortitis.

Aortitis refers to an abnormal inflammation of the aortic wall and may have infectious, inflammatory or idiopathic etiologies. Patients with aortitis may require a multidisciplinary approach for appropriate diagnosis [3].

The clinical manifestations are usually nonspecific and sometimes may mimic other diseases [4].

Symptoms can develop due to mass effect over adjoining structures, like in our case. In fact, our patient developed a significant left ureterohydronephrosis caused by the inflamed aorta.

Clinical features of aortitis are nonspecific and may include fever. Patients may have elevated serum levels of acute-phase reactants [1]. Consideration of a large differential diagnosis and awareness for potentially serious underlying pathology is always needed for the proper diagnosis of aortitis.

Multimodality imaging approach can help in the assessment of these patients and are often required for making the diagnosis.

In fact, CTA (computed tomographic angiography), MR (magnetic resonance) and PET (positron emission tomography) are essential in diagnosing and assessing disease activity. Imaging is also useful for guided biopsy.

On the CT scan, there are signs to differentiate infectious aortitis from inflammatory aortitis [3,4].

In inflammatory aortitis, the arterial lumen is often smooth and regular and the wall thickens outward.

Infectious aortitis are saccular, with lobulated contours and associated with inflammatory involvement of the peri-aortic spaces.

In our case, the signs of aortitis were in favour of an inflammatory origin but the etiological assessment of the inflammatory or infectious aortitis was negative (temporal arteritis, syphilis).

We, therefore, present here the first described case of LZMG presenting in the form of an abdominal aortitis, sheathing the urethra.

This rare case teaches us that an aortitis of the aortic bifurcation which has not proved its origin must lead to rule out a neoplastic context.

Treatment of aortitis is related to the etiology, ranging from management of noninfective aortitis consists of immu-immunosuppression with high-dose corticosteroid, antibiotics to endovascular treatment or surgery.

In our case, regression of the aortitis occurred precisely when the patient was treated with specific chemotherapy type Rituximab/Bendamustine.