Bajwa Suhaib A., Kasi Anup
University of Kansas
An accessory spleen, also called a supernumerary spleen, a splenule, or a splenunculus, is a benign and asymptomatic condition in which splenic tissue is found outside the normal spleen. Accessory spleens are a relatively common phenomenon with an estimated 10% to 30% of the population having one. Typically, an individual can have anywhere from one to six accessory splenic buds. Furthermore, the size of an accessory spleen can also vary. Most accessory spleens are approximately 1 centimeter, but it is not uncommon to find accessory spleens larger than a few centimeters. Accessory spleens typically form due to developmental anomalies and are often confused with splenosis which is another form of ectopic splenic tissue. Splenosis arises from trauma which results in a portion of the spleen breaking off and embedding itself somewhere else in the peritoneal cavity. The newly embedded ectopic splenic tissue recruits local blood supply and becomes functional splenic tissue. An accessory spleen can be distinguished from splenosis since an accessory spleen is functionally and histologically similar to normal splenic tissue, but splenosis is missing key splenic characteristics such as a thick capsule, smooth muscle elements, and a blood supply arising from the splenic artery.
副脾，也称为额外脾、小脾或脾小结，是一种良性且无症状的情况，即在正常脾脏之外发现脾组织。副脾是一种相对常见的现象，估计有10%至30%的人口有一个副脾。通常，一个人可以有1到6个副脾芽。此外，副脾的大小也会有所不同。大多数副脾约为1厘米，但发现几厘米以上的副脾也并不罕见。副脾通常由于发育异常形成，常与脾组织植入混淆，脾组织植入是异位脾组织的另一种形式。脾组织植入源于创伤，导致脾脏的一部分脱落并植入腹膜腔的其他部位。新植入的异位脾组织募集局部血液供应并成为功能性脾组织。副脾可以与脾组织植入区分开来，因为副脾在功能和组织学上与正常脾组织相似，但脾组织植入缺少关键的脾特征，如厚包膜、平滑肌成分和来自脾动脉的血液供应。
