Amale infant was born with a massive orbitocranial tumor without evidence of metastasis. On light microscopy, the histologic pattern of the tumor was that of a largely necrotic and highly undifferentiated small round cell neoplasm of uncertain origin. Ultrastructural features of the primitive cells included a rare tight junction and myofibril. Immunohistochemical studies showed positive staining for cytokeratin, vimentin, muscle-specific actin, neuron-specific enolase, and S100 protein and negativity for desmin and leukocyte common antigen. We believe this case represents an example of a polyphenotypic small-cell tumor of childhood with epithelial, rhabdomyoblastic, and neuroectodermal differentiation.
Lyon DB, Dortzbach RK, Gilbert-Barness E. Polyphenotypic Small-Cell Orbitocranial Tumor. Arch Ophthalmol. 1993;111(10):1402-1408. doi:10.1001/archopht.1993.01090100110037