This is a case of choroid plexus carcinoma. The patient underwent a right-sided craniotomy for the excision of the mass within the right lateral ventricle.

Pathologic analysis showed that the tumor is composed of epithelioid cells with clear cell changes and demonstrated worrisome features including:

• largely solid, compact, hypercellular, and highly mitotically mass, with only focal areas of papillary architecture

• significant cytologic pleomorphism

• high p53 labeling

There was evidence suggestive of brain invasion by the tumor. No evidence of tumor necrosis. The tumor was positive for Cam-5.2, MNF-116, and P53 (>90%), with diffuse but weak staining for Syn.9

When combining the abovementioned histomorphology and stain profiles, this atypical tumor was classified as a choroid plexus carcinoma, CNS WHO grade 3.

Co-author:
Travis Bevington, MD