[Primary splenic cysts. Report of 5 cases, 4 of which unpublished and review of the literature].

After a complete review of the literature with an amount of 280 previously reported cases, the authors report on five total cases of primary (true) cysts of the spleen one of which already published. All these cases occurred in pediatric age and were treated by total splenectomy. All were large solitary cysts (size ranged from 4.5 up to 15 cm) but one, the largest of which in addition to the main cavity exhibited some more microscopic cysts of the same type few mm sized. Three of them were lined on their inner surface by a multilayered squamous epithelium, which in one case was also keratinized. The other two cysts showed a single layered epithelium which appeared flattened in one case, cubic in the other one. The discussion concerns the pathogenetic mechanisms which can lead to cyst formation, the imaging diagnosis of these rare lesions prior to surgical intervention, their treatment, and the correct histological recognition of these true cysts versus secondary (false) cysts or pseudocysts which commonly occur following trauma. One of the cases herein presented qualifies as a "pseudo-pseudocysts" due to the fact that a history of trauma was on record and to the fact that almost the entire epithelium was mechanically lost due to hemorrhage which filled the cyst cavity.