Benign Neoplasms of the Spleen

1. Splenic cysts
• true cyst - has endothelial lining
• epidermoid
• parasitic
• pseudocyst - lacks endothelial  lining 
• post traumatic - most common
• both are well defined masses, attentuation similar to water on CT, do not enhance with contrast administration, high signal on T2WI
2. Hemangioma
• most common benign neoplasm
• US: small cystic masses, may show flow on color Doppler
• CT: hypodense on NCECT, post contrast images show early centripetal nodular enhancement with delayed uniform enhancement
• MR: hypointense on T1WI, hyperintense on T2WI
• diffuse hemangiomatosis
• Klippel-Trenaunay-Weber
• Kasabach-Merritt-like
• Beckwith-Weidemann
3. Hamartoma
• associated with tuberous sclerosis
• heterogeneously hyperintense relative to spleen on T2WI
• diffuse enhancement in early post contrast phase that becomes more uniform on delayed images
4. Lymphangioma
• US: well defined, hypoechoic mass, internal septations, may have echogenic debris
• CT: splenomegaly, single or multiple hypodense masses, may have peripheral calcifications, no enhancement post contrast
• MR: hypointense T1WI, hyperintense T2WI

REFERENCES

Elsayes KM, Narra VR, Mukundan G, et al. MR imaging of the spleen: spectrum of abnormalities. Radiographics 2005;25:967-82.

Urrutia M, Mergo PJ, Ros LH, et al. Cystic masses of the spleen: radiologic-pathologic correlation. Radiographics 1996;16:107-29.