Curative Resection of Hepatic Alveolar Hydatids

An ultrasound examination of an asymptomatic 67-year-old German man during a routine medical consultation revealed two space-occupying lesions in the right lobe of the liver. Magnetic resonance imaging (MRI) located these two lesions to segment V and VII, respectively (Figure 1a, arrowheads), and hepatic malignancy or metastasis was suspected. MRI revealed no further lesions in the abdomen, lungs or brain. Endoscopy was unremarkable and tumor markers alpha-fetoprotein (AFP), carcinoembryogenic antigen (CEA), and cancer antigen (CA) 19-9 were within normal range. Serology was highly positive for Echinococcus multilocularis in a crude antigen-screening ELISA and in the confirmatory recombinant antigen-ELISA and immunoblot. Antiparasitic chemotherapy with albendazole (400 mg b.i.d.) was initiated, and the patient underwent hemihepatectomy and regional lymphadenectomy. Gross pathology of the resected liver tissue showed two adjacent alveolar lesions (Figure 1b), corresponding to the metacestode stage of E. multilocularis. Histological examination of the lesions demonstrated multiple eosinophilic vesicular structures surrounded by necrosis, fibrosis, and round cell infiltration (Figure 1c), a typical aspect of human alveolar echinococcosis. Based on to the World Health Organization’s staging system, we diagnosed stage II (P2N0M0). Albendazole therapy was well tolerated, and a 15-month followup period was uneventful. No regrowth of parasitic tissue could be detected on the follow-up MRI. Antibodies directed against a crude parasite antigen extract and the recombinant antigen Em10 showed a constant decline during the observation period (Figure 1d), which is consistent with a curative resection. Accordingly, immunoblot analysis of the first and last serum obtained showed a loss of one genus-specific band at 7 kDa and two speciesspecific bands at 16 and 18 kDa (Figure 1d, inset).