Wandering spleen was first reported in 1667, and since then to 2024, there have been less than 600 cases reported in PubMed’s database, with estimates of a 0.2% incidence rate in reported splenectomies [1,2]. The spleen is the largest reticuloendothelial organ in the human body, with essential roles in immunological defense and hematologic maintenance [6]. The average adult spleen measures longitudinally between 9 and 14 cm with an average weight of 135g [6,7]. Its anatomic position in the left upper quadrant is tethered in place by several suspensory ligaments, including the gastrosplenic ligament, splenorenal (also known as lienorenal) ligament, phrenicocolic ligament, and phrenicosplenic ligaments [7].

The encapsulated spleen is an intraperitoneal organ located at the left hypochondrium of the abdominal cavity. Any compromise to the structural integrity of these ligaments, or their congenital absence, can lead to splenic hypermobility, known as wandering spleen. This condition allows the spleen to migrate to various distant locations, including the pelvis [1]. As a result of this excessive mobility, the vascular pedicle may result in mechanical distortion or torsion. 

The vascular pedicle of the spleen is comprised of the gastrosplenic and splenorenal ligaments, with the splenorenal ligament containing the distal splenic artery, vein, and inferior portion of the pancreatic tail [7]. With torsion, the venous return is compromised, leading to vascular congestion and splenomegaly. Arterial flow to the spleen may eventually be compromised, leading to ischemia and infarction, requiring emergent surgical intervention.

Because these cases are rare, determining the incidence is challenging. The incidence previously cited is 0.16% based on a review of thousands of splenectomies in studies conducted in 1981 and 1992 [3,8]. There is a demographic predisposition for the wandering spleen in pediatric cases, accounting for approximately one-third of cases, with presentations typically occurring below the age of 10 years, and a 1:1 male-to-female ratio [8]. This has been previously theorized to result from an abnormal embryologic development of the dorsal mesogastrium merging with the posterior abdominal wall [4], hence defects or congenitally absent gastrosplenic and phrenicosplenic ligaments [8], leading to an elongated splenic vascular pedicle susceptible to axial twisting. The majority of other cases have been historically reported to be in multiparous female populations between the ages of 20-40 years [5], with a recent theorized explanation that both estrogen and progesterone increased relaxin concentrations and its receptor expression on various supporting tissue, thus increasing ligamentous laxity and creating the predisposition of increased risk for the wandering spleen phenomenon [9,10].

The clinical presentation can be asymptomatic or may include nonspecific symptoms such as acute or chronic colicky abdominal pain, dysuria, splenomegaly, or a palpable abdominal/pelvic mass. Patients may also experience gastrointestinal symptoms such as constipation, bloating, nausea, and vomiting. In females, menstrual complications can also occur [11]. According to the National Organization of Rare Disorders, thrombocytopenia and anemia may develop secondary to an enlarged spleen with compromised blood flow, leading to symptoms such as fatigue, weakness, hematochezia, and hematemesis [11]. Although point-of-care ultrasound has been utilized to diagnose wandering spleen in the emergency department, cases are more accurately diagnosed using contrast-enhanced CT of the abdomen [12]. CT imaging findings include abnormal splenic orientation, change in anatomical location, splenic infarction, splenic vein thrombosis, swirling of the vascular pedicle, vascular engorgement, hyper enhancement of the spleen or its vessels, and perisplenic fat stranding [12]. In cases where splenic architecture is distorted or the vascular pedicle is poorly defined, a Technetium-99m sulfur colloid scan may be utilized for a more definitive diagnosis [12].

Definitive treatment is surgical management with splenectomy being recommended [12]; however, a 1989 report reviewed 35 cases of pediatric acute and chronic wandering spleens that additionally underwent splenoplexy using a Dexon mesh or conservative management without deaths reported as well  [13]. Due to the elevated mortality rates associated with post-septectomy infections in adults (1.3%) and in children (1.7%), with notably higher rates in those with hematologic disorders such as sickle cell anemia (4.8%) and thalassemia major (5.1%), the importance of administering post-splenic vaccinations cannot be overstated [14].

Our patient presented as a multiparous female with a history of ITP. There have been reported cases of thrombocytopenia in the presentation of a wandering spleen in literature [15], as well as splenomegaly leading up to the cases of wandering spleen observed by Abell in his review [5], however, these findings have been thought to be attributed to the impaired splenic venous return from the rotated vascular pedicle. Chronic ITP was notably mentioned due to the known mechanism by which the majority of IgG autoantibodies bind to platelet glycoprotein surfaces, such as integrin αIIb-βIII complexes, leading to platelet destruction via splenic macrophages [6]. Although the spleen is not usually enlarged in cases of ITP, a palpable spleen may still be palpable in some patients [6].

It is difficult to conclusively report the exact cause of the patient's wandering spleen presentation, and it was speculated that her splenomegaly of 376g and corresponding perivascular fibrosis with reactive changes may have played a compounded role. With either systemically weakened or congenitally absent splenic suspensory ligaments (less likely given her acute presentation in adulthood and absent history regarding spleen disorders) and increased spleen mass from initial ITP, the spleen's increased momentum set the stage for splenic torsion.

The possibility of splenoplexy was a management option that was discussed with the patient; however, given the nature of the patient's acute presentation and history of ITP, laparoscopic detorsion would have been procedurally difficult with a high rate of recurrence, given the elongated splenic pedicle. Furthermore, her concurrent history of ITP would also have the highest long-term response rate with a splenectomy [6].