Hepatic Visceral Larva Migrans Presenting as a Pseudotumor

Abstract

h c d l f n i A woman was referred for the assessment of a focal hepatic lesion of fortuitous discovery. The patient’s edical history was remarkable for adenocarcinoma of the reast that had been in remission for 10 years. Routine laboraory results including liver test function and tumor markers ere within normal limits. Imaging study revealed a unique odular lesion of 26 mm in hepatic segment IV, hyperechoic in bdominal ultrasonography, and low density in computed toography (Figure A, arrow). Magnetic resonance imaging showed a nodule that exhibited low intensity in T2 (Figure B, arrow) and high intensity in T1 and presented slightly heterogeneous contrast enhancement after gadolinium injection. Imaging characteristics ruled out focal steatosis, angioma, or focal nodular hyperplasia. In the context of malignancy history, ultrasound-guided liver biopsy of the lesion was conducted. Histologic analysis showed an encapsulated abscess (Figure C). At higher magnification (Figure D), it was made of a mixture of necrotic hepatocytes and large amounts of altered eosinophils, and many Charcot–Leyden crystals, appearing as refringent yellowish spindle-cell structures, were irregularly scattered among these cells. No parasitic structures were visible. Tumoral process was absent. Serologic antibody testing for various helminthic infections was negative except for Toxocara canis, with a titer of 34 U in enzyme-linked immunosorbent assay (normal range, 9 U), and confirmatory Western blot test showed 5 positive bands (normal, 2). This resulted in the conclusive diagnosis of visceral toxocariasis. The patient was managed with albendazole 400 mg 3 times a day associated with ivermectin 12 mg per week for a total of 3 weeks. Magnetic resonance imaging control 6 months after treatment was normal, consistent with favorable outcome. Toxocara canis is the main cause of visceral larva migrans in humans. It may affect multiple visceral organs, and the liver is the most involved site, usually mimicking tumoral processes.1 Lesions are usually described as oval, ill-defined nodules, either unique or more frequently multiple.2,3 Noninvasive approach as been advocated for contributing to diagnostic issue by ombining imaging and serologic testing. Visceral larva migrans iagnosis is to be ascertained when managing investigations for iver nodules caused by eosinophilic infiltrate to disclose them rom metastatic deposits. Treatment of symptomatic forms is ot well codified, and albendazole alone or in combination with vermectin has been reported to be effective.