[Accessory spleen on the left ovary. Discussion on its pathogenesis]

The authors report a case of an accessory spleen attached to the left ovary, discovered in a hysterectomy and bilateral adnexectomy specimen obtained for leiomyoma. This is an exceptional congenital anomaly as only seven cases have been reported in the medical literature. It may be classified as a type of spleno-gonadal fusion. It is always localized to the left side. This anomaly may be manifest as an inguinal tumefaction or by an intestinal occlusion requiring exploratory laparotomy. It is caused by fusion of the spleen to the left urogenital bud during the 5th to 8th weeks of fetal development.