DIAGNOSIS OF INFLAMMATORY PSEUDOTUMOR OF THE LIVER - VALUE OF CT

OBJECTIVE. Inflammatory pseudotumor of the liver is a localized mass c onsisting of a fibrous stroma and chronic inflammatory infiltrate with out anaplasia. Diagnosis of this rare disease is important to avoid su rgery. The purpose of this study was to determine if CT is useful in t he diagnosis of this lesion. SUBJECTS AND METHODS. CT scans of nine pa tients with a proved diagnosis of inflammatory pseudotumor of the live r were reviewed. Diagnosis was made by the surgical resection in three patients and by percutaneous biopsy in six patients. Six patients had symptoms and laboratory data suggesting active inflammation caused by the pseudotumor. The remaining three patients were asymptomatic. CT s cans were performed with IV administration of the contrast material; s cans were obtained in the portal venous and delayed phases in six pati ents and in the delayed phase in three patients. CT scans were analyze d for the number and size of the hepatic masses, and the degree and pa ttern of contrast enhancement on portal venous phase and delayed-phase images. RESULTS. Eight patients had a solitary hepatic mass, and one patient had two masses on the CT scan. The average size of the masses in the symptomatic patients (8.3 cm) was larger than that in the asymp tomatic group (3.6 cm). CT scans in the portal venous phase showed a v ariable degree of contrast enhancement (seven masses). At least a part of seven masses, six of which were in symptomatic patients, showed gr eater contrast enhancement on delayed-phase CT scans than on the norma l liver parenchyma. No constant pattern of enhancement was observed on delayed-phase CT scans in asymptomatic patients. CONCLUSION. inflamma tory pseudotumor of the liver should be included in a differential dia gnosis in patients with a hepatic mass on a CT scan, especially when p atients are symptomatic and the mass is fairly large and solitary show ing contrast enhancement greater than that of liver parenchyma on dela yed phase CT scans. Percutaneous biopsy should be performed to obtain a histologic confirmation.