Sclerosing angiomatoid nodular transformation of the spleen masquerading as a sarcoma metastasis

We report a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen presenting as an incidental splenic mass in a patient with a history of retroperitoneal spindle cell sarcoma. Imaging studies and preoperative fine needle biopsy failed to differentiate this lesion from other vascular splenic lesions or a metastatic focus of a prior sarcoma. The patient was treated with splenectomy, which has proved both diagnostic and therapeutic in this and other cases of SANT. Although histology can lead to the diagnosis of vascular tumor, immunohistochemistry is the only way to confirm the diagnosis of SANT. The etiology of SANT is unknown. SANT of the spleen is a benign lesion that does not recur after splenectomy.