Diagnostic Ultrasound - Abdomen and Pelvis

Splenic Tumors
Diagnoses: Spleen
IMAGING
• All tumors (benign and malignant) can have variable
appearances, a lot of overlap by US
• Benign tumors
○ Hemangioma: #1 benign splenic tumor; classic =
echogenic
○ Hamartoma: Classic = echogenic, homogenous
○ Lymphangioma: Classic = hypoechoic, loculated,
avascular; younger age
○ Littoral cell angioma: Rare; variable appearance,
splenomegaly
• Malignant tumors
○ Lymphoma (HD, NHL, primary splenic, AIDS-related),
leukemia, myeloproliferative disorders
– Classic: Diffuse SMG; if focal: Hypoechoic, indistinct
margins
○ Metastasis (breast, lung, ovary, stomach, melanoma)
– Cystic, solid, or mixed; can be targetoid lesions
KEY FACTS
○ Primary splenic malignancies very rare (angiosarcoma
most common of these)
• Color Doppler vascularity may be helpful if present (to
conclude not cyst), but absent color flow does not entirely
exclude benign or malignant tumor
TOP DIFFERENTIAL DIAGNOSES
• Splenic infarct
• Splenic infection/abscess
• Splenic cyst
• Splenic hematoma
• Hepatosplenic sarcoidosis
DIAGNOSTIC CHECKLIST
• Primary splenic malignancies are rare; biggest diagnostic
dilemma is usually an indeterminate splenic lesion in
patients with extrasplenic malignancy (i.e., is it metastasis or
not)
• Considerable overlap in US findings; reliable differentiation
on imaging is not always possible, requires histology
(Left) Grayscale ultrasound
image of the spleen in a
patient with hepatitis C (HCV)
and previously treated
hepatocellular carcinoma
(HCC) shows a solitary solid
mass in the spleen with
central hyper-echogenicity st
and peripheral hypoechogenicity
ſt (target-like
pattern). (Right) Color Doppler
evaluation of the lesion
demonstrates a small amount
of flow within the lesion ,
confirming its solid (not-cystic)
nature.
(Left) Corresponding axial
contrast-enhanced CT image
shows the solitary, solid
hypoattenuating splenic lesion
ſt. Also, note the presence of
peritoneal soft tissue implants
along the surface of the liver
. (Right) ¹⁸F FDG PET/CT
fusion image in the same
patient shows intense
metabolic activity of the
splenic lesion ſt, peritoneal
implants , and sites of
hepatic involvement. Histology
revealed large B-cell
lymphoma. Note that HCC
metastasis to the spleen is
rare; HCV infection has been
linked to B-cell lymphomas.
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