Diagnostic Ultrasound - Abdomen and Pelvis

Splenic Cyst
Diagnoses: Spleen
IMAGING
• Can be classified as primary (congenital) vs. secondary
(acquired) or true (epithelial lined) vs. false (no epithelial
lining)
○ Secondary more common than primary (80% vs. 20%)
○ Hydatid cyst is an example of acquired true cyst
• Classically, anechoic to hypoechoic, avascular, sharply
defined spherical lesion with posterior acoustic
enhancement
○ Variable presence of internal debris/septation, wall
calcification depending on type and etiology
TOP DIFFERENTIAL DIAGNOSES
• Inflammatory or infection
○ Pyogenic, fungal, or granulomatous abscess
• Neoplastic
○ Benign (hemangioma, lymphangioma) or malignant
(cystic metastasis, lymphoma)
• Vascular
KEY FACTS
○ Hematoma, infarction, peliosis, intrasplenic
pseudoaneurysm
• Intrasplenic pancreatic pseudocyst
DIAGNOSTIC CHECKLIST
• Rule out infectious, vascular, and neoplastic cystic lesions
• Consider if congenital or acquired cyst
○ Congenital (epidermoid): Typically larger, anechoic, with
thin wall; ± calcification or debris (less common)
○ Acquired: Most commonly post-traumatic; usually
smaller, often anechoic, but may have debris; thicker wall
± calcification
• Often impossible to distinguish primary vs. secondary (or
true vs. false) cysts by imaging
(Left) Axial CECT of the left
upper quadrant shows a large,
rim-calcified, post-traumatic
pseudocyst in the anterior
spleen ſt. (Right) Zoomed-in
view of the left
subdiaphragmatic space on
frontal chest radiograph in the
same patient shows the cyst
delineated by thin rim
calcification .
(Left) Grayscale US shows an
anechoic splenic pseudocyst
with curvilinear rim
calcification ſt, which causes
posterior acoustic shadowing
. (Right) Gross pathology of
an acquired pseudocyst in the
spleen shows a calcified,
fibrous wall .
404