Table 2.

Differential diagnosis table of wandering spleen

Differential Diagnosis	US	CT	MRI
Ectopic spleen	-Ectopically located spleen which may be normal sized or enlarged. -If complicated by torsion, the spleen may be normal in echogenicity/have altered echotexture/appear hypoechoic. Thrombosed, enlarged splenic vein in B-mode is hypoechoic in acute thrombosis and echogenic in subacute or chronic cases. Color doppler imaging shows no flow in the splenic vein. Torsed splenic pedicle may be difficult to visualize by ultrasound. - Splenic infarction, if present, may be focal or complete. Focal infarctions are seen as wedge shaped, sharply defined hypoechoic foci extending up to the splenic capsule. Completely infarcted spleen appears uniformly hypoechoic with altered echotexture. -Free fluid may be present.	-Complicated ectopic spleen is best assessed by CT. -If complicated by torsion, whorled appearance of twisted pedicle is diagnostic. The degree of torsion corresponds to the number of twists the vascular pedicle has undergone. The thrombosed, engorged splenic vein does not show enhancement following contrast administration. -Splenic infarction if present, are seen as non-enhancing, wedge shaped hypodensities in the arterial phase. Status of adjacent viscera can be assessed if they get tangled within the twisted pedicle. Most commonly pancreatic tail may be involved.	-Splenic infarcts are seen as wedge shaped areas hypointense in T1 & T2WI, with no enhancement following contrast administration.
Appendicitis	-Spleen is in its normal location. -Dilated (>6mm), tubular, non-peristaltic, blind-ending loop in right iliac fossa with surrounding free fluid.	Inflamed appendix visualized +/− appendicolith.	Inflamed, dilated appendix with wall edema (T1 hypointense, T2 hyperintense) & appendicoliths (T1 & T2 hypointense).
Ovarian mass/cyst	-Spleen is in its normal location. Ovarian mass is heterogeneous. Cysts are anechoic or turbid, +/− septations, +/− mural components.	Ovary not visualized separately from the mass or cyst.	Best imaging modality to characterize ovarian masses/cysts.
Diverticulitis	-Spleen is in its normal location. -Probe tenderness at site of diverticulitis. -Diverticula may be detected using linear probe.	Diverticula easily detected in the colon. Inflamed diverticula with surrounding fat stranding or abscess formation seen.	Inflamed diverticula seen as T2 hypointense outpouching from the colonic wall.
Ruptured ectopic pregnancy	-Spleen is in its normal location. -Hemoperitoneum -Adnexal mass	-Adnexal mass separate from the ovary -Hemoperitoneum	-Hemoperitoneum -If the gestational sac is still intact after rupture of the fallopian tube, it can be visualized.