Orbital mesenchymal chondrosarcoma: Report of a rare tumor in a Nigerian girl

The orbit (eye socket) is one of the rare extraskeletal sites of mesenchymal chondrosarcoma (MC). This is a report of the clinical presentation, the results of radiological and histopathological investigations, as well as the treatment outcome of a case of orbital MC in an 11-year-old Nigerian girl who presented with right eye protrusion and worsening vision. Examination of the right eye revealed lagophthalmos with marked proptosis of the globe. Right eye modified exenteration was done due to progressive proptosis, pain, and no perception to light. Histology revealed a biphasic neoplasm that is composed of well-formed hyaline cartilage and sheets of undifferentiated mesenchymal cells with a diagnosis of MC. She had four courses of cytotoxic chemotherapy, and was initially clinically stable on follow-up, but had a recurrence due to noncompletion of chemotherapy and radiotherapy. Orbital MC should be considered among young females who present with progressive proptosis, with or without pain, and worsening visual impairment.