Abstract
Background: Cytologic description of pineal parenchymal tumors are extremely rare. We report a case of mixed pineocytoma-pineoblastoma with spinal metastasis. Proliferative activity of this rare tumor was also examined.
Case: A pineal tumor was detected in a 9-year-old girl who had congenital microcephalus. Imprint and squash cytology of the resected tumor showed small uniform cells with round to oval nuclei and focal rosette-like structures. A small number of relatively large cells with hyperchromatic nuclei were also observed. Histologically, the tumor was composed of a pineocytoma area with pineocytomatous rosette and highly cellular pineoblastoma area with Homer Wright rosette. Spinal fluid cytology revealed pineoblastoma cells with relatively large, hyperchromatic and pleomorphic nuclei with scanty cytoplasms. The MIB-1 positive rate of the pineocytoma area was 2.5% and that of pineoblastoma area was 36.7%.
Conclusion: The high proliferative potential of the pineoblastoma component may relate to tumor relapse and spinal metastasis.
