Light microscopy showed a very cellular tumor that was composed of undifferentiated round to oval tumor cells with darkly hyperchromatic nuclei and indistinct cytoplasm. The tumor cells showed a diffuse growth with no recognizable arrangement. Immunohistochemical staining revealed that the tumor cells were strongly positive for vimentin, desmin, and myoglobin and negative for epithelial membrane antigen, keratin, neuron-specific enolase, S100 protein, and leukocyte common antigen.
Proptosis With Violaceous Dermal and Subcutaneous Skin Nodules in an Infant. Arch Dermatol. 2002;138(5):689-694. doi:10.1001/archderm.138.5.689