Hepatic Small Vessel Neoplasm: A Case Report and Review of the Literature

Abstract

Hepatic small vessel neoplasm (HSVN) is a recently described vascular neoplasm of the liver. It demonstrates an infiltrative growth pattern and lacks cytologic atypia and mitotic activity. So far, no cases of metastasis or disease recurrence after excision have been reported in the literature. In this report, we present the case of a 31-year-old woman with a lesion in segments VII-VIII of the liver who was referred to our surgical department due to right lumbar pain. She underwent an atypical wedge hepatectomy (segments VII, VIII) and cholecystectomy. The histopathology of the resected specimen confirmed a 40mm HSVN. The patient did not receive any adjuvant therapy and is scheduled for follow-up with serial magnetic resonance imaging (MRI) scans over the next five years due to the unknown malignant potential of the tumor.

Keywords: differential diagnostic process; hepatic neoplasm; hepatic small vessel neoplasm; liver; vascular neoplasm.

Figure 1. Axial T1 FL2d ΜRI image of the liver and axial T2 fat suppressed MRI image of the liver; white arrow shows a segment VII lesion

Figure 2. Contrast-enhanced ultrasound (CEUS) of the liver; white arrow shows a segment VII lesion

Figure 3. Gross photograph of surgical specimen of HSVN (circle) demonstrating a vascular unencapsulated tumor with a poorly circumscribed border

Figure 4. Microscopic appearance of the neoplasm

H&E stain x100 (a, b), x200 (c), x400 (d), erythroblast transformation specific related gene (ERG) stain x200 (e), CD31 stain x100 (f); Proliferation of small, thin-wall vessels infiltrating hepatic parenchyma (a, b). Portal tracts are entrapped within the neoplasm (c). Higher magnification reveals plump, ovoid endothelial cells with no significant nuclear atypia lining neoplastic vessels (d). Neoplastic cells stain positive for ERG (e) and CD31 (f), confirming the vascular nature of the neoplasm.