Imaging Findings:
Images of the dedicated CT of the liver demonstrate an oval lesion with central necrosis and a hypovascular rim that is isodense on equilibrium phase. A subtle hypervascular surrounding rim ("corona") on arterial phase is present, just barely seen on the demonstrated arterial phase image. Imaging findings are suspicious for metastasis.
Ultrasound-guided biopsy revealed extensive infiltration of plasma cells, mixed type of inflammation and fibrosis, consistent with inflammatory pseudotumor.
Compare differences in imaging findings with contrast-enhanced ultrasound.
Subsequent ultrasound three weeks later demonstrated complete spontaneous resolution of this lesion.
CT of the chest and abdomen performed one year later for suspected pulmonary embolism demonstrated unchanged resolution of this lesion (not shown). It also showed punctated residual hypodense foci of two other subtotally resolved lesions, presumably inflammatory pseudotumors as well, but an interim development of a 7 cm melanoma metastasis in the upper abdomen (not shown).
Courtesy Dr. Gerd Stuckmann, Institute for Radiology and Nuclear Medicine, Kantonsspital Winterthur, Switzerland.