Parachordoma: a case report.

Parachordoma is a very rare soft tissue tumor with histological features similar to chordoma and chondrosarcoma. It should be distinguished from metastatic chordoma and extraskeletal myxoid chondrosarcoma because of its different treatment and prognosis. In this paper we report one case of parachordoma in a 20-year-old female patient. The tumor occurred in the subcutaneous tissue of the left hand as a painless, fixed, slow-growing mass. Pathologic analysis revealed a tumor composed of lobules of cells with variably vacuolated cytoplasm (physaliphorous cells) separated by fibrous septa, predominantly arranged in peculiar small or large alveolar structures. Immunohistochemistry showed positive staining of the tumor cells with cytokeratin 8/18, S-100 protein and vimentin. The patient is well and without recurrence 20 months after surgery.