Mediastinal ganglioneuroma with perineural cell differentiation. Report of a case.

An unusual case of ganglioneuroma with perineural cell differentiation is presented. The tumor was removed from the mediastinum in a 34-year-old male patient. Histologically, it contained neuroid bundles of bland spindle cells, scattered ganglion cells, and some foci of adipocytic metaplasia. Immunohistochemically, the tumor showed expected expressions of S100 protein, neurofilament protein and calretinin. In addition, many spindle cells were positive for perineural cell markers EMA, claudin-1, and GLUT-1. These cells were often arranged in an organoid fashion around the schwannoid bundles. This case indicates that the cells of ganglioneuroma can mature simultaneously towards both Schwann cell and perineural cell phenotypes.