IgG4-related inflammatory pseudotumor of the liver presenting as an incidental solitary liver mass

Abstract

Inflammatory pseudotumor is increasingly being recognized as a definitive pathological entity affecting many organ systems and often difficult to distinguish from malignancy. We report a case of a 48-year-old female who presented with right hypochondrial pain associated with nausea and vomiting and recent weight loss. An ultrasound scan demonstrated gallstones without evidence of cholecystitis and an incidental 1.5 cm mass in the left liver lobe. A computed tomography (CT) and a magnetic resonance imaging (MRI) scan described the mass suspicious of a malignant tumour. An ultrasound-guided biopsy confirmed a benign inflammatory mass with lymphoplasmacytic infiltration staining for IgG4 and no evidence of malignancy. The patient had an elevated serum IgG4 levels. The patient was kept under surveillance. She underwent a laparoscopic cholecystectomy and at 18 months following the initial presentation the patient remains asymptomatic with stable liver lesion on ultrasound scan.