Hepatic inflammatory pseudotumor presenting in an 8-year-old boy: A case report and review of literature

Abstract

Hepatic inflammatory pseudotumors are uncommon benign lesions. Accurately diagnosing hepatic inflammatory pseudotumor can be very challenging because the clinical presentation and radiological appearances are nonspecific and cannot be certainly distinguished from malignant neoplastic processes. Herein, we present a case of hepatic IPT in an 8-year-old boy who presented to clinic with a 3-mo history of a tender hepatic mass, fever of unknown origin, and 9-kg weight loss. The physical examination was notable for tender hepatomegaly. Laboratory investigations were notable for a normal hepatic profile and elevated erythrocyte sedimentation rate and C-reactive protein. A T2-attenuated magnetic resonance imaging scan of the abdomen showed a 4.7 cm × 4.7 cm × 6.6 cm, contrast-enhancing, hyper-intense, well-defined lesion involving the right hepatic lobe. In view of the unremitting symptoms, tender hepatomegaly, thrombosed right hepatic vein, nonspecific radiological findings, and high suspicion of a deep-seated underlying infection or malignancy, a right hepatic lobectomy was recommended. Microscopically, the hepatic lesion exhibited a mixture of inflammatory cells (histiocytes, plasma cells, mature lymphocytes, and occasional multinucleated giant cells) in a background of dense fibrous tissue. Immunohistochemically, the cells stained negative for SMA, ALK-1, CD-21 and CD-23, diffusely positive for CD-68, and focally positive for IgG4. The final histopathological diagnosis was consistent with hepatic IPT. At the postoperative 4-mo follow-up, the patient was asymptomatic without radiological evidence of recurrence.

Keywords: Hepatic; Inflammatory myofibroblastic tumor; Inflammatory pseudotumor; Liver.

Figure 1

Contrasted-enhanced computed tomography scan of the abdomen. A: Arterial phase: a 6.3 cm × 5.1 cm × 5.5 cm, relatively well-defined, hypo-dense lesion with internal enhancement involving the right hepatic lobe (segments# V, VI and VII); B: Delayed venous phase: the right hepatic vein was thrombosed, whereas the middle and left hepatic veins, as well as the inferior vena cava, were patent.

Figure 2

T2-attenuated magnetic resonance imaging scan of the abdomen. A: A 4.7 cm × 4.7 cm × 6.6 cm, contrast-enhancing, hyper-intensive, well-defined, and moderate- to large-sized lesion involving the right hepatic lobe (segments# V, VI and VII); B: There was extension of the known hepatic IPT lesion into the path of the right hepatic vein.

Figure 3

Fine-needle aspiration of the focal hepatic lesion. The smear contains a mixture of benign hepatocytes with histiocytes (Diff Quick stain, magnification power: × 40).

Figure 4

Gross picture of the right hepatic lobectomy. There is a focal, soft, fleshy, yellow-white, and tanned nodule measuring 8 cm × 6 cm × 5 cm.

Figure 5

Focal hepatic lesion was surrounded by a well-demarcated thin capsule (HE stain, magnification power: × 20).

Figure 6

Microscopic picture of the focal hepatic lesion displaying a mixture of inflammatory cells (histiocytes, plasma cells, mature lymphocytes, and occasional multinucleated giant cells) in a background of dense fibrous tissues. The inflammatory cells were mostly concentrated around the sub-capsular area at the periphery (A) and around the blood vessels (B) (HE stain, magnification power: × 40).

Figure 7

Immunohistochemical analysis of the focal hepatic lesion. A: All histiocytes in the lesion stained diffusely positive for CD-68 (HE stain, magnification power: × 40). B: A few plasma cells in the lesion stained focally positive for IgG4 (IgG4 stain, magnification power: × 40).