Quiz. Correct answer to the quiz. Check your diagnosis. Mesenchymal chondrosarcoma of the orbit: two cases and a brief review of the literature.

Mesenchymal chondrosarcoma (MChS) is a rare, high-grade malignant tumor which occurs both in the bone and soft tissue. The extraskeletal location comprises one third of all MChS and in review of the up-to-date literature, about 30 cases of the orbital involvement were found. The authors present clinical, radiological and pathological findings of two cases of MChS of the orbit occurring in young adult females: primary extraskeletal MChS of the orbit and skeletal MChS of the ethmomaxillary complex with secondary orbit involvement. The histopathological examination revealed a characteristic biphasic pattern composed of small round to spindle-shaped cells, mimicking Ewing sarcoma family of tumors, with areas of a haemangiopericytoma-like pattern and admixed cartilage foci. One of the patients had local recurrence 3 years after initial surgical removal. Subsequently, she underwent enucleation followed by chemotherapy. The other patient had a biopsy and debulking resection of the tumor and started chemotherapy. Ten months follow-up of this patient show no evidence of metastasis.