The spleen is the largest lymphoid organ with a parenchymal structure in the entire body. However, because of the uncommonness of splenic disease, the spleen has been considered a “forgotten organ,” even though it is included and well demonstrated on abdominal images obtained with various imaging modalities.
As with other abdominal viscera, the exact differential diagnoses for splenic lesions are important for selection of appropriate strategies to minimize unnecessary invasive diagnostic procedures, such as percutaneous biopsy or surgery. However, it often is difficult to differentiate benign splenic lesions from malignant tumors for the following reasons: (a) the radiologic features of many splenic lesions overlap, (b) splenic lesions tend to manifest with vague clinical symptoms, and (c) abnormalities and primary tumors of the spleen are uncommonly encountered in daily clinical practice. These factors make it challenging for radiologists to accurately distinguish among various benign and malignant lesions.