Myxoid intravascular fasciitis.

Nodular fasciitis is a common reactive proliferation of soft tissue. It is composed of high density of fibroblasts and myofibroblasts, and sometimes shows a sarcomatoid appearance histologically. A rare variant of nodular fasciitis, intravascular fasciitis can be found in the veins or arteries. Histologically, intravascular fasciitis has been described that resembles nodular fasciitis with a less prominent mucoid matrix. Here, we report a case of intravascular fasciitis with prominent mucin deposition. Clinically, it presented as multiple nodules on the leg of the patient. Histologically, it showed proliferation of spindle cells in a vein of the dermis and Alcian blue staining confirmed prominent mucin deposition between the spindle cells. Immunohistochemistry studies showed the spindle cells were positive for vimentin, actin and smooth muscle actin, but negative for keratin, S100 protein, desmin, CD31 and CD34. Based on the clinical and histopathological properties, a diagnosis of myxoid intravascular fasciitis was made.