Primary lymphoma of the spleen mimicking simple benign cysts: contrast-enhanced ultrasonography and other imaging findings.

We report on a case of incidentally detected primary splenic lymphoma mimicking simple benign cysts on abdominal ultrasonography. On contrast-enhanced ultrasonography (CEUS), the lesions showed isoenhancement in the arterial phase with progressive washout and marked hypoenhancement in the parenchymal phase. This pattern enabled us to suspect the malignant nature of the disease, thus preventing a dangerous misdiagnosis. Accordingly, further characterization with other imaging studies (computed tomography, magnetic resonance imaging, and positron emission tomography) was pursued based on CEUS and taking into account the patient's clinical picture and medical history. Collectively, imaging data led us to a diagnosis of suspected primary splenic malignancy, most probably lymphoma, which was histologically confirmed on the surgical specimen after splenectomy.