Case 375:   Echinococcosis, alveolar

Diagnostic Category:

Clinical Presentation:

55 year-old man from Switzerland with right upper quadrant pain, fever, and unintentional weight loss for 2 months.

CT: Calcifications, with peritoneal and pleural manifestation

Imaging Findings:

CT demonstrates a well, but irregularly defined mass in the right lobe with nodular margins and a right lateral curvilinear calcification. No contrast enhancement within or surrounding the mass. Note capsular involvement anteriorly and pleural thickening posteriorly.

PET-CT demonstrates no FDG-avidity of the mass, but mild FDG-avidity of the pleura.

Ultrasound guided biopsy of the mass revealed active alveolar echinococcosis, which had infested the peritoneum, diaphragm and right pleura.