Arteriomegaly and inflammatory abdominal aortic aneurysm. Case report.

In this case report inflammatory abdominal aortic aneurysm (IAAA) was superimposed on an arteriomegaly condition complicated by bilateral aneurysm of the common iliac arteries. Obstruction of the right ureter, mild hydronephrosis of the left system and a slight impairment of renal function were also present. Preoperative cellular and humoral immunological parameters were within normal limits while the erythrocyte sedimentation rate (ESR) was elevated (74 mm). Histological analysis showed numerous scattered lymphoid cells or organized in follicles with germinal centers within the adventitial thickening of the IAAA wall. Immunohistochemical analysis on frozen sections demonstrated that dispersed and perivascular lymphoid cells were mainly composed of similar amounts of CD3+/CD4+ and CD3+/CD8+ T lymphocytes. Histological analysis of the common iliac artery aneurysm showed a mild intimal thickening will small aggregates of macrophages. After aneurysm repair all peripheral blood analysis normalized within one month after surgery. The IAAA observed in our patient with arteriomegaly as underlying arterial disease cannot be interpreted as an inflammatory variation of an atherosclerotic aneurysm. The histological pattern of the inflammatory reaction and its resolution after surgery give, in our opinion, more credit to the etiopathogenetic hypothesis of a reaction elicited by an antigen within the arterial wall of the infrarenal aorta which might be enhanced by the lymphatic stasis subsequent to aneurysm compression.