Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology

Abstract

The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.

Applications of Contrast-Enhanced Ultrasound in Splenic Studies of Dogs and Cats

“…On the other hand, when it comes to the use of CEUS in the diagnosis of splenic diffuse alterations, there are few published works that emphasize its advantages over the conventional ultrasound. Examples are a splenomegaly (congestion, splenic hyperplasia/extra medullary hematopoiesis, and inflammatory splenomegaly), an accessory spleen, and an inhomogeneous spleen of unknown causes [ 70 , 71 , 72 ]. Table 1 summarizes CEUS findings in benign splenic lesions.…”

“…CEUS was shown to be useful where there is doubt about the origin of a peri splenic mass (accessory spleen/splenunculis) or of tissue that has arisen post-splenectomy or post-trauma (splenosis) [ 58 ]. An accessory spleen has an incidence of around 16% in humans, and it is communally located at the splenic hilum and in the tail of the pancreas and presentes as nodules of variable size (from 1–4 cm) [ 72 , 83 ]. Normally, accessory spleens are easily identified with a conventional ultrasound, but large or atypically located spenunculi can cause diagnostic uncertainty, being misinterpreted as a pathological peritoneal nodule or enlarged lymph node [ 58 , 72 ].…”

“…An accessory spleen has an incidence of around 16% in humans, and it is communally located at the splenic hilum and in the tail of the pancreas and presentes as nodules of variable size (from 1–4 cm) [ 72 , 83 ]. Normally, accessory spleens are easily identified with a conventional ultrasound, but large or atypically located spenunculi can cause diagnostic uncertainty, being misinterpreted as a pathological peritoneal nodule or enlarged lymph node [ 58 , 72 ]. CEUS can confirm that a mass represents ectopic splenic tissue, demonstrating an enhancement pattern typical of normal spleen, which is the persistent late phase enhancement, and differentiating the mass from other lesions such as pancreatic tail tumors, splenic hilar lymph nodes, adrenal lesions, ovarian masses, and metastatic deposits [ 58 , 71 ].…”