Figure 2.

Gross and microscopic findings from EBV-related SMN of liver. Liver specimen from Patient 3 measured 17 × 13.2 × 7.6 cm. Four nodules were found, ranging in size from 0.4 cm to 6.7 cm (a). Histologic features on H&E staining included moderate increased cellularity (with areas containing rounder, less fusiform cells), lack of nuclear pleomorphism, and a low mitotic rate (1 mitotic figure/50 high-powered field) (b). Nearly all cells were positive for EBV-EBER by ISH, although intensity of the staining varied from cell to cell (c). Electron microscopy revealed spindle cells with abundant cytoplasmic aggregates of actin microfilaments, including fusiform dense bodies and attachment plaques, confirming the diagnosis of a well-differentiated smooth muscle proliferation (d).