Benign cysts are rare and usually asymptomatic. Cysts are of variable origin and maybe uniocular (one cavity) or multiocular (multiple cavities). The most common forms of the cyst are post-traumatic, congenital, and parasitic. The congenital cyst is usually uniocular and filled with clear fluid that may contain cholesterol crystals. Congenital cysts may contain a squamous or endothelial lining. Parasitic cysts are typically echinococcal cysts which are extremely rare in the United States. Post-traumatic cysts form from the slow liquefaction of a hematoma (bruise), contain a cloudy brown fluid, and have a fibrous (firm, thick) lining. Though the cysts are mostcommonly without any symptoms, occasionally they present as a mass in the left upper quadrant of the abdomen.
Peliosis lesions refer to blood filed lakes in the parenchyama. These lesions occur in the spleen, usually in assosiation with peliosis of the liver. The origin of peliosis is unknown, but has been associated with chemotherapy or steroid use. The biggest problem with this lesion is that with or without trauma the peliosis can rupture, which can be fatal. Treatment of incidently found peliosis be determined by the surgeon at the time of discovery. Treatment of Splenic Cysts
Treatment is indicated for symptomatic cysts. Aspiration with pure alcohol or tetracycline antibiotics has been reported in literature, but with limited success due to a high rate of recurrence. Resection using either partial or full splenectomy is optimal treatment. Often this is done laparosopically. Echinoccal cysts should be handled with care because there is a higher risk of rupture.