Intraocular Teratoid Medulloepithelioma Presenting With a Completely Rhabdomyosarcomatous Distant Metastasis.

Abstract

Medulloepithelioma is the second most common primary neuroepithelial tumor of the eye. The full range of its morphologic expressions and appearances in metastases have not been fully explored. A patient in her 50s with glaucoma for decades had undergone multiple filtering surgical procedures, including the placement of a glaucoma drainage device. A paraspinal mass was discovered, and tumor and bone marrow biopsies disclosed rhabdomyosarcoma. This led to the discovery of a multicystic intraocular tumor. A metastatic rhabdomyosarcoma to the eye was considered unlikely because, to our knowledge, this event had never been reported. An enucleation was performed, and an intraocular tumor composed almost entirely of rhabdomyoblasts (desmin- and myogenin-positive) was discovered along with rare clusters of persistent neuroepithelial cells. To our knowledge, this is the first case of a medulloepithelioma in which teratoid rhabdomyoblasts effaced all but trace amounts of neuroepithelium and generated a distant metastasis entirely composed of rhabdomyoblasts. The prolonged history and filtering procedures probably led to these 2 phenomena.