Fig2. Immunohistochemistry for PLAP antibody shows positive cytoplasmic staining in tumoral cells.

A mass biopsy of the right skull base reveals a broad pattern of medium to large cell neoplastic growth. These cells exhibit pleomorphism, a high mitotic rate, a high N/C ratio, and crashing. IHC staining is Ki67 positive in about 60%, OCT focally positive, CK dot-like positive, CD10 and PALP positive.