Neuroradiological characteristics of ecchordosis physaliphora. Case report and review of the literature.

An extremely rare case of ecchordosis physaliphora is presented in which the authors focus especially on its radiological characteristics. The patient complained of a headache with no other neurological abnormalities. A thorough radiological examination revealed a small intradural prepontine mass with no bone destruction of the clivus. Magnetic resonance imaging was very useful in visualizing this mass as a low signal intensity lesion on T1-weighted images and as a high signal intensity lesion on T2-weighted images without any contrast enhancing effects. At surgery, a cystic gelatinous nodule was found ventral to the pons; the nodule was connected to the dorsal wall of the clivus via a delicate stalk. Histological studies proved that this was an ecchordosis physaliphora. Review of the literature demonstrates that the reported cases of ecchordoses have many common radiological features that would suggest the diagnosis of this rare disease.