Presentation
Infant with a mass on CT (not shown) for further evaluation
Patient Data
Left lateral intraventricular mass lesion.
The patient went on to have a craniotomy and debulking of the tumor.
Histology
Frozen section diagnosis: Left lateral ventricular tumor: Malignant neoplasm, differential between choroid plexus carcinoma and atypical teratoid rhabdoid tumor and anaplastic ependymoma.
Immunohistochemistry: CTK+, EMA+, GFAP+, NFP-, VIMENTIN+, SYNAPTOPHYSIN+, CD56 focal, BAF-47 absent, SMA+
Electron Microscopy: EM07-513
FINAL DIAGNOSIS: Atypical teratoid / rhabdoid tumor (AT/RT)
Case Discussion
This very aggressive tumor with extension into the ventricles was shown to be an atypical teratoid / rhabdoid tumor (AT/RT), which more frequently occurs in the posterior fossa. A reasonable differential on imaging in this age group is of a choroid plexus carcinoma.