Fig. 2

a Microscopically at low-power (×10), the lesion was composed of multiple, variably sized, circumscribed and confluent angiomatoid nodules with a central vascular core and a fibrosclerotic stroma on periphery. Different vessels in the nodules had distinct immunophenotypes, three kinds of vessels were positive for CD31 (b, × 40), the capillaries were positive for CD34 (c, ×40), and the dilated sinusoid like vessels were positive for CD8 (d, ×10). Plasma cells in the stroma revealed IgG+ (Fig. 2 e) and some few of which showed IgG4+ (Fig. 2 f) (<50/HP)