gms | German Medical Science

Objective: Chordoma is a rare, potentially malignant neoplasm, believed to derive from the fetal notochord affecting adults primarily. It occurs in the whole neuroaxis, but is mainly seen in the clival or sacral area. For poorly differentiated chordoma, loss of expression of SMARCB1/INI1, a possible tumor suppressor gene, has been described recently. Here, we report three cases of children with atypical chordoma and loss of SMARCB1/INI1 expression all with completely different clinical manifestations, thereby reviewing the literature.

Method: We retrospectively reviewed all patients identified with an atypical chordoma. Patient demographics, clinical presentation, operative procedures, pathology, and outcome were determined.

Results: Of the three cases, two presented with ongoing sensible deficits and motor weakness of the limbs, the other one with palsy of the abducens nerve. The neoplasms were located in the clival area, the cervical and the lumbosacral spine. All three cases presented with bony infiltration. MRI revealed contrast enhancing lesions. Histopathological workup resulted in increased proliferation rate and loss of expression of SMARCB1/INI1 accordable to a poorly differentiated chordoma. All patients received surgery, followed by adjuvant radiation and chemotherapy in two cases and proton beam therapy in one case. Early metastasis in the lung, liver and local lymph nodules has been seen in one child, early recurrence in another whereas the third child is still recurrence free.

Conclusions: Atypical chordomas in children are aggressive neoplasms with a high incidence of recurrence. Loss of expression of SMARCB1/ INI1 seems to be important for malignant transformation of chordomas and for their clinical manifestation. In the case of loss of expression of SMARCB1/ INI1 a staging for systemic metastasis should be added. In addition to avoid early recurrence the neoadjuvant and adjuvant therapeutic strategies should follow closely after surgical resection.