[Non-parasitic cysts of the spleen: report on two cases and ultrastructural findings in one of them (author's transl)].

Two cases are reported of non-parasitic cysts of the spleen of the simple epithelial type. The pathogenic mechanism of such cysts is discussed and illustrated by ultrastructural findings in one of the cases. The wall of this cyst was mesothelial in nature. This observation is in favour of the inclusion of mesothelial tissue in the spleen, a hypothesis suggested in the published literature by several authors.