A Case of Splenic Sclerosing Angiomatoid Nodular Transformation

Abstract

At a follow-up visit after colonic polypectomy, a 52-year-old man complained of a 7-kg weight loss over the past 4 years. Abdominal computed tomography showed a 5-cm, well circumscribed, poorly enhanced mass in the spleen. Since the cross-sectional imaging findings did not exclude the possibility of malignancy, and the patient consented resection, we performed hand-assisted laparoscopic surgery (HALS) for splenectomy. The mass measured 6.5×5.0×4.0 cm. On section, it was whitish, solid, and contained multiple red-brown nodules. Histological examination showed multiple angiomatoid nodules in a fibrosclerotic stroma. The results of immunohistochemical analysis for CD34, CD8, CD31 indicated sclerosing angiomatoid nodular transformation (SANT). It is a very rare disease, and only 9 cases have been reported in Japan. Since it is difficult to diagnose SANT by imaging, its definitive diagnosis requires surgery.