Diagnostic Ultrasound - Abdomen and Pelvis

Hepatic Diffuse Microabscesses
Diagnoses: Liver
TERMINOLOGY
• Typically refers to hepatic candida abscesses in
immunocompromised patients
IMAGING
• Multiple small hypoechoic lesions throughout liver (most
common pattern)
• Target sign (hyperechoic center with hypoechoic halo) or
bull's-eye configuration
• Wheel within a wheel pattern may be present in larger
fungal lesions
• Multiple small, hyperchoic foci throughout liver (occurs in
later stages)
• Lesions may resolve completely or calcify after successful
treatment
• Similar lesions may be found in spleen
TOP DIFFERENTIAL DIAGNOSES
• Simple cysts
KEY FACTS
• Necrotic metastases
• Hepatic lymphoma
• Sarcoidosis
• Biliary hamartomas
PATHOLOGY
• Fungal infection: Most commonly Candida albicans, but may
also include Cryptococcus, histoplasmosis, mucormycosis,
Aspergillus
○ Occur more commonly in immunocompromised patients
(leukemia, lymphoma, AIDS/post transplant)
• Pyogenic infections can appear similarly in patients with GI
or biliary tract infection
DIAGNOSTIC CHECKLIST
• Rule out other causes of multiple liver lesions such as
hepatic cysts, hepatic lymphoma, metastases, sarcoidosis
• Liver biopsy with culture often necessary to verify the
lesions are due to fungal infection
(Left) Transverse color
Doppler ultrasound of a
hepatic fungal abscess
shows characteristic wheel
within a wheel or target
appearance. Notice the fungal
abscess is avascular in
appearance. (Right)
Longitudinal grayscale US
shows multiple hypoechoic
fungal abscesses ſt
throughout the liver in an
immunocompromised patient.
(Left) Transverse
transabdominal ultrasound
shows a patchy heterogeneous
echotexture due to diffuse
involvement ſt by Candida
microabscesses. (Right)
Longitudinal ultrasound in the
same patient 2 years after
treatment for disseminated
candidiasis shows multiple
hyperechoic, punctate
parenchymal calcifications ſt
typical of treated Candida
microabscesses.
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