We will begin our guided tour with splenic anatomy as it correlates to splenic immunologic and filtering function, which will allow us to better understand benign and malignant splenic abnormalities. The majority of spleen specimens are removed for non-malignant etiologies, and we will accordingly learn about hyperplasias, developmental abnormalities, traumatic lesions, vascular/mesenchymal lesions, and systemic disorders as manifest in the spleen. We will use our anatomic and functional understanding of splenic architecture to guide our approach to splenic malignancies.