Mixed capillary venous retroperitoneal hemangioma

Abstract

We report a case of mixed capillary venous hemangioma of the retroperitoneum in a 61-year-old man. Abdominal ultrasonography showed a mass to be hypoechoic with increased flow in color Doppler imaging. Dynamic contrast-enhanced computed tomography revealed a centripetal filling-in of the mass, located anterior to the left psoas muscle at the level of sacroiliac joint. On the basis of imaging features, preoperative diagnosis of hemangioma was considered and the mass was excised by laparoscopic method. Immunohistochemical studies were strongly positive for CD31 and CD34, and negative for calretinin, EMA, WT1, HMB45, Ki67, synaptophysin, and lymphatic endothelial cell marker D2-40. Histologically, the neoplasm was diagnosed as mixed capillary venous hemangioma.

Figure 1

Grey-scale ultrasonography shows (a) a mild heterogenous hypoechoic mass with posterior acoustic enhancement anterior to the left psoas muscle with increased flow within the mass on color Doppler imaging (b) (arrow).

Figure 2

Dynamic contrast enhanced computed tomography. During the arterial phase (a), lesion demonstrates an initial peripheral nodular, with subsequent centripetal progressive filling-in pattern during venous (b) and equilibrium phase (c) (arrow).

Figure 3

Diffuse immunoreactivity of tumor cells to CD31 (a) and CD34 (b) confirms an endothelial origin.

Figure 4

Histopathologic examination of the resected specimen. The neoplasm is composed of vein with thick muscular wall and proliferation of small capillary-sized vessels (hematoxylin and eosin, ×40).