Splenic  cysts include congenital (true) cysts; nonpancreatic pseudocysts (post traumatic hematoma), cystic neoplasms (lymphangiomas, haemangiomas, lymphomas and metastases), inflammatory lesions (abscesses and parasitic cysts).

Congenital cysts are generally true cysts and contain an epithelial lining (also called epidermoid, epithelial or congenital cysts) whereas pseudocysts do not have an epithelial lining.

True cysts are believed to be developmental in origin.Pseudocysts presumed to be post-traumatic in origin, may be hemorrhaegic or serous and may be the end stage of  intrasplenic hematoma 75- 80 % of the cysts are pseudocysts.

True and false cysts can appear identical on cross sectional imaging. Both are well defined, homogenous and unilocular. Although it may be impossible to differentiate between true and false cysts on imaging studies, there are few differential points to consider.

False cysts, which tend to be smaller, have internal debris and peripheral calcification.Pheripheral calcification is less common in true cysts.

The diagnosis of false cyst should be should be favored when, there is clear history of trauma, the patient is older than 40 yrs or there is hematoma elsewhere in the spleen. On CT scan both true and false cysts have an attenuation value near or equal to that of water, their walls are either thin or imperceptible, and they do not enhance after iv administration of a contrast agent. On MRI both types of cysts appear to contain fluid with signal intensity greater than that of water.