Splenic anomalies of shape, size, and location: pictorial essay

Abstract

Spleen can have a wide range of anomalies including its shape, location, number, and size. Although most of these anomalies are congenital, there are also acquired types. Congenital anomalies affecting the shape of spleen are lobulations, notches, and clefts; the fusion and location anomalies of spleen are accessory spleen, splenopancreatic fusion, and wandering spleen; polysplenia can be associated with a syndrome. Splenosis and small spleen are acquired anomalies which are caused by trauma and sickle cell disease, respectively. These anomalies can be detected easily by using different imaging modalities including ultrasonography, computed tomography, magnetic resonance imaging, and also Tc-99m scintigraphy. In this pictorial essay, we review the imaging findings of these anomalies which can cause diagnostic pitfalls and be interpreted as pathologic processes.

Figure 1

Axial contrast enhanced CT images (a)–(e) and post-contrast T1-weighted MR image (f) show examples of different type of persisting splenic fetal lobules and shape variations, which were incidentally detected in six different patients. Note the close relation of the medially oriented splenic lobules with upper pole of the left kidneys in (a) and (c).

Figure 2

Axial contrast enhanced CT images show examples of splenic clefts in four different patients which were incidentally detected. In (b) there are also coexisting fetal lobules at the medial aspect of the spleen.

Figure 3

Axial nonenhanced (a) and contrast enhanced (b, c) images show accessory spleens in three different patients. In (a), a 51-year-old male patient has three accessory spleens which are located at splenic hilum and anterior to the spleen. In (b), a 59-year-old male patient has an accessory spleen located at the lateral aspect of the spleen (arrow). In (c), a 50-year-old male patient has an anteriorly located accessory spleen; note its vascular supply originating from splenic artery (arrowhead).

Figure 4

Axial contrast enhanced CT image (a), contrast enhanced T1-weighted image at arterial (b) and venous phases (c) show an intrapancreatic nodular mass in a 63-year-old female patient. The mass has similar density at CT and contrast enhancement pattern at MR images with the spleen indicating an intrapancreatic accessory spleen.

Figure 5

Accessory spleens can locate at the wall of stomach or bowel. Axial contrast-enhanced CT image (a) with oral contrast medium shows a nodular hyperdense lesion (arrow) indenting the posterior wall of the stomach in a 57-year-old female patient. The follow-up axial nonenhanced image (b) with oral water shows persistence of its high density indicating an accessory spleen. Axial contrast enhanced CT image (c) shows an accessory spleen located closely to the colonic wall (thick arrow).

Figure 6

Axial contrast enhanced CT image of a 29-year-old male patient shows splenopancreatic fusion anomaly.

Figure 7

Coronal venous phase MIP image shows a wandering spleen (star) located at pelvis and its vascular pedicle (white arrow) originating from splenic artery (black arrow).

Figure 8

Axial contrast enhanced CT images of a 19-year-old female patient who was presented with acute abdominal pain. There is no splenic tissue at left upper quadrant (a) and a heterogenously hypodense mass (arrows) of a torsioned wandering spleen at midline (b) which was proven surgically. Hypodense parenchyma indicates infarction.

Figure 9

Heterotaxy syndrome in 48-year-old male (a), (b) and 49-year-old female patients (c). Axial contrast enhanced CT images (a), (b) show polysplenia (white arrows) at left upper quadrant which have heterogenous enhancement pattern on arterial phase as splenic tissue, azygos continuation (black arrow) of the inferior vena cava, and right renal vein draining into the azygos vein (arrowhead). Intrahepatic portion of the inferior vena cava is absent. Axial contrast enhanced CT image (c) shows, polysplenia at right upper quadrant (white arrows), absence of spleen at its normal location, liver located at midline related to situs ambiguous, and dilated azygos vein (black arrow).

Figure 10

Splenosis in a 62-year-old male patient with a history of splenic trauma and splenectomy. Axial contrast enhanced CT images (a, b) show two splenic fragments (thick arrow) on the left upper quadrant (a) and a nodular mass (arrow) with a heterogenous contrast enhancement pattern as splenic tissue posterior to the liver and kidney (b). Axial T2 weighted image (c) demonstrates similar signal intensity of both the nodular mass (arrow) and inferior pole of the splenic fragments (thick arrow). Technetium-99 m posterior scintigraphy image (d) also shows uptake of the nodular mass (arrow) as splenic tissues on the left (thick arrow).

Figure 11

Axial contrast enhanced CT image at bone window demonstrates small and calcified spleen of a patient with sickle cell disease.

Figure 12

Axial contrast enhanced CT image with oral contrast medium reveals a hyperdense mass posterior to the stomach and medial to the spleen. The gas bubble anterior to the mass (arrow) helps gastric diverticulum in differentiating it from an accessory spleen.

Figure 13

Nonenhanced axial CT image (a) of a 48-year-old female patient reveals a soft tissue mass (arrow) nearby greater curvature of the stomach. On coronal reformatted contrast enhanced CT image, there is a stalk (black arrow) between left lobe of the liver and the mass (white arrow) indicating accessory liver.

Figure 14

Axial contrast enhanced CT images (a), (b) of a 54-year-old male patient show wandering accessory spleen (arrow) anterior to the spleen which is at different locations in consecutive examinations.