Diagnostic Ultrasound - Abdomen and Pelvis

Focal Splenic Lesion
– Typically multiple well-defined, small, hypoechoic
lesions (early); multifocal small calcifications
(chronic/healed)
• Hemangioma
○ Most common benign tumor of spleen
○ Typically well-defined, hyperechoic solid lesion;
echogenicity can be variable (range from solid to cystic to
mixed); ± calc when complex
○ May be solitary or multiple (splenic hemangiomatosis,
Klippel-Trenaunay-Weber syndrome, etc.)
• Malignant Neoplasm
○ Lymphoma
– Most common malignant tumor of spleen; primary vs.
secondary/systemic
– Focal, multifocal, or diffuse; hypoechoic or
cystic/pseudocystic
□ May contain internal irregular cystic area
representing necrosis
□ Occasionally, markedly hypoechoic lymphoma
infiltrate has pseudocystic appearance
□ Hyperechoic lesions less common
– Indistinct boundary echo pattern
– Evidence of disease elsewhere in liver, adenopathy
○ Metastasis
– Multifocal lesions with variable size & appearance; iso-
/hypo-/hyperechoic; solid, cystic, or mixed
□ Common primary sites = breast, lung, ovary,
stomach, melanoma
□ Cystic metastases from melanoma,
adenocarcinoma of breast, pancreas, ovaries, and
endometrium
□ May be hyperechoic due to coagulative necrosis
(hemorrhage), seen in melanoma, or calcification,
as in mucinous adenocarcinomas
– Target lesions with hypoechoic halo
– Other evidence of disseminated disease
• Splenic Infarct
○ Classically peripheral, wedge-shaped, hypoechoic &
hypo- or avascular; bright band sign
• Splenic Hematoma/Laceration
○ History of trauma is crucial
○ Peripheral (extending from capsular margin), band-like or
wedge-shaped, hypo- or hyperechoic depending on
stage of hematoma, avascular
Helpful Clues for Rare Diagnoses
• Hamartoma
○ Typically well-defined, homogeneous, hyperechoic
○ Variable echogenicity, vascularity; ± cystic change or calc
• Lymphangioma
○ Most occur in childhood; typically subcapsular location
○ Well-defined anechoic or hypoechoic complex cystic
mass ± internal septations & intralocular debris; ± wall
calc
○ Avascular on color Doppler, unless along cyst walls
• Littoral Cell Angioma
○ Commonly benign, though malignant has been reported
○ Variable echogenicity & vascularity; solitary or multiple;
almost always with splenomegaly, hypersplenism
• Angiosarcoma
○ Heterogenous solid mass; majority (> 70%) have
associated metastasis in liver
• Sarcoidosis
○ Hepatic involvement more common than splenic
○ Splenomegaly; multiple hypoechoic nodules (or
iso/hyper); calcified in chronic phase
• Peliosis
○ Rare, idiopathic; associated with malignant hematologic
disease, disseminated metastases, TB, etc.
○ Widespread blood-filled cystic spaces of varying size ±
endothelial lining
○ Thrombosis within blood-filled spaces may occur
• Intrasplenic Pseudocyst
○ Pancreatic pseudocyst (1-5% of patients with
pancreatitis)
○ Well-defined, rounded, cystic splenic lesion; associated
inflammatory changes of pancreas
Differential Diagnoses: Spleen
Acquired Splenic Cyst
Acquired Splenic Cyst
(Left) Transverse US of a
splenic pseudocyst
demonstrates posterior
through transmission st and
internal septation ſt. Note
that this appearance is
nonspecific; a congenital
epidermoid cyst may have a
similar appearance. A history
of trauma may aid in diagnosis
of acquired pseudocyst. (Right)
Corresponding coronal CECT
shows the cyst with internal
septation ſt and calcification
(not seen on the US). Both
acquired and congenital cysts
may have calcification, though
more common in acquired
cysts.
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