A Case of Sclerosing Angiomatoid Nodular Transformation Discovered during a Medical Check-up

Abstract

Here, we report a case in which a splenic mass was incidentally discovered during a medical check-up at our hospital. Subsequent splenectomy led to a diagnosis of sclerosing angiomatoid nodular transformation (SANT). The patient was a man in his 40s undergoing treatment for dyslipidemia. Abdominal ultrasonography revealed a splenic mass (diameter; 23 mm) during a medical check-up that was not detected previously. Contrast-enhanced computed tomography (CT) performed at the General Internal Medicine Department of our hospital revealed a slightly irregular splenic mass with a relatively clear border and diameter of 35 mm at the same location. Subsequently, the patient was transferred to another hospital, and contrast-enhanced CT and magnetic resonance imaging revealed continuous mass growth. Therefore, laparoscopic splenectomy was performed. Histopathological findings led to the diagnosis of SANT. SANT is a rare, non-neoplastic vascular lesion of the spleen that is often asymptomatic and incidentally discovered during imaging. As they tend to grow, malignant diseases must be eliminated with certainty to ensure effective treatment. However, pathological diagnosis of surgically resected specimens is necessary for a definitive diagnosis of SANT. Therefore, SANT must be considered as a differential diagnosis for splenic masses detected on abdominal ultrasonography during medical check-ups or health examinations.