Giant ecchordosis physaliphora in an adolescent girl: case report.

The authors describe a rare case of giant ecchordosis physaliphora (EP) in a 16-year-old female patient who presented with diplopia. Magnetic resonance imaging of the brain with Gd contrast revealed a 3.0 × 1.7 × 1.8-cm nonenhancing, extraaxial epidural mass along the dorsal aspect of the clivus that was T2 hyperintense and T1 isointense with intermediate signal on diffusion sequences. Resection via a transnasal transsphenoidal approach to the ventral clival wall resulted in a stable tumor size with no evidence of interval growth after 30 months. Although this case features a strictly extradural EP, this tumor more commonly occurs in the subdural space and requires differentiation from intradural chordoma. Unlike EP, intradural chordoma may enhance with Gd contrast, is more likely to be associated with cranial nerve palsies and brainstem symptoms, and will occasionally have an elevated MIB-1 index. In this paper the authors highlight the different possible midline locations for both EP and chordoma, the difficulty in distinguishing between intradural giant EP and intradural chordoma, and the potential occurrence of these lesions in young people despite their typically slow rate of growth, while also underscoring the need for further investigation into the tumors' cytogenetic behavior.