Wenbo Xiao MD, Presenter: Nothing to Disclose

Jingjing Xu, Abstract Co-Author: Nothing to Disclose

Sclerosing angiomatoid nodular transformation (SANT) is a benign, primary nonneoplastic vascular lesion of the spleen. Its radiologic depiction was only scattered case reports in the pathology, and radiology literatures. We present, for the first time, eight cases of SANT completely with imaging findings including computed tomography (CT), magnetic resonance imaging (MRI), and pathological correlation and propose that certain imaging features may suggest the diagnosis.

We report eight cases of SANT. These cases performed ultrasound, dynamic enhanced CT and MR examination. Spleen resection were performed in all of the patients. Histological, immunohistochemical characteristics confirmed the diagnosis of SANT.

Seven patients had no symptoms. Their discoveries of a splenic tumor were an incidental finding. One patient had upper abdominal discomfort and discovered the tumor on routine health examination. Histologically，all cases were characterized by multiple angiomatoid nodules of various sizes in a fibrosclerotic stroma．The nodules were round and sometimes convoluted．They were composed of slit-like, irregular-shaped or slightly dilated vascular spaces lined by plump endothelial cells and interspersed with a population of spindly or ovoid cells．CT image shows predominantly hypodense mass with lobulated contours. Postcontrast arterial and delayed venous phase demonstrated diffuse peripheral enhancement with progressive centripedal filling in a radiating pattern, while its center remained hypodense, which is similar to spoke wheel pattern. The spoke-wheel pattern also was observed on MRI. T2-weighted MR image shows peripheral hypointense with central hyperintense areas which are different form the previous reports.

Sclerosing angiomatoid nodular transformation is a rarely encountered benign lesion of the spleen，which should be distinguished from other angiomatoid tumors and tumor-like lesions．The lesion showed progressive enhancement from periphery to center of lesion and the central hyperintense areas like a central scar on T2-weighted images is the image features. To the best of our knowledge, the MRI findings of this rare entity have not been published before.

MR demostrates a unlike spoke-wheel pattern of SANT which can be an important image feature for diagnosis and differential diagnosis for this rare entity.

Xiao, W, Xu, J, CT and MRI Findings of Sclerosing Angiomatoid Nodular Transformation of the Spleen.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11010462.html