Presentation
Headaches.
Patient Data
Hydrocephalus. Pineal region mass, coarse calcification of the tumor, mild enhancement.
Differential: A germ cell tumor (both germinoma and non-germinoma germ cell tumor, the latter particularly in view of coarse calcification) is favored over a pineal parenchymal tumor (e.g. pineoctyoma or pineal parenchymal tumor with intermediate differentiation),
Post-ventriculostomy, CSF accumulating deep to scalp with the third ventriculostomy obstructed by clot or tumor spread.
MICROSCOPIC DESCRIPTION:
Paraffin sections show multiple small fragments of a densely hypercellular tumor. These are composed of atypical large cells with round and oval vesicular nuclei containing conspicuous amphophilic nucleoli and a narrow rim of pale cytoplasm. These cells show strong immunostaining for c-kit and patchy weak staining for placental alkaline phosphatase (PLAP) and CD30 and are admixed with moderate numbers of CD3+ T lymphocytes and lesser numbers of CD20+ B lymphocytes and CD68+ monocyte-macrophages. No staining for GFAP is
seen. The features are of germinoma. The topoisomerase proliferation index is approximately 40%. No normal pineal tissue is identified.
FINAL DIAGNOSIS: Germinoma