Final Diagnosis -- coccygeal chordoma (coccygeal mass)



Contributor's Note:

Chordoma is an uncommon malignant tumor of bone thought to originate in notochordal remnants. It arises almost exclusively in the midline and occurs most commonly in the sacrococcyx, cervical spine, and clivus. Embryologically, the anatomy and development of the notochord involves numerous complicated infoldings of this structure at the cranial and caudal ends of the neuraxis, which may explain why notochordal remnants tend to remain at these points and potentially give rise to tumors, while the intervening notochord segments involute. Prognosis of the lesion is dependent on the surgical resectability of the tumor; obviously, chordomas of the clivus, being in a relatively inaccessible anatomical location and surrounded by vital structures, has a poorer overall outcome when compared to a sacrococcygeal lesion. Death usually occurs secondary to uncontrolled local growth of the neoplasm; metastatic spread of chordoma can occur but is seldom the primary cause of mortality.
Chordoma is characterized grossly by a soft, lobulated, firm grey to white tumor which can have a mucoid appearance. Histologically, the lesion consists of multiple lobules of small round tumor cells separated by a myxomatous stroma. The cells often display cordlike patterns of growth and have prominent vacuolation of the cytoplasm, imparting a bubbly appearance on low power examination. The cells with this characteristic have been termed "physaliphorous" and are distinctive for this neoplasm. Positive immunostaining for cytokeratins, EMA, and S100 are typical. Cytogenetic studies of this neoplasm have noted several karyotypic abnormalities, but no characteristic and reproducible findings have been reported to date. Occasionally, areas of chondroid differentation can be seen in some chordomas. Some investigators have linked such differentiation to a poorer overall outcome; some have postulated that these lesions represent a borderline lesion between chordoma and myxoid chondrosarcoma.


DeBoer JM, Neff JR, Bridge JA: Cytogenetics of Sacral Chordoma. Cancer Genet Cytogenet 64:95-96, 1992.

Jeffrey PB, Biava CG, Davis RL: Chondroid Chordoma: A Hyalinized Chordoma without Cartilaginous Differentiation. Am Journ Clin Path 103(3): 271-9, Mar 1995.

Magrini SM, Papi MG, Marletta F, Tomaselli S, Cellai E, Mungai V, Biti G: Chordoma: Natural History, Treatment, and Prognosis. Acta Oncol 31(8): 847-851, 1992.

Salisbury JR: The Pathology of the Human Notochord. Jour of Path 171: 253:255, 1993.

Salisbury JR, Deverell MH, Cookson MJ, Whimster WF: Three Dimensional Reconstruction of Human Embryonic Notochords: Clue to the Pathogenesis of Chordoma. Jour of Path 171:59-62, 1993

Contributed by Kevin D. Horn, M.D.

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