Splenic tissue in the ovary: Splenosis, accessory spleen or spleno-gonadal fusion?

Ectopic splenic tissue in any location could represent accessory spleen, a common congenital abnormality, splenosis, the presence of numerous nodules of ectopic splenic tissue after spleen trauma/surgery or splenogonadal fusion, a rare congenital malformation found mostly in males. Ectopic splenic tissue in the ovary is usually found in the context of an extensive pelvic splenosis. Solitary ovarian splenosis presenting not as a part of pelvic splenosis, but rather as a solitary mass masquerading an ovarian tumor is extremely rare. Differential diagnosis in this case includes mostly splenosis and splenogonadal fusion of the discontinuous type. Relevant literature and possible pathogenesis are discussed.