gms | German Medical Science

Objective: Tumors of the pineal region (PR) are rare, and an appropriate pathologic classification and grading of tumors are essential for determining clinical management and prognosis. The diagnostic evaluation, however, should nowadays include molecular analyses.

Method: 18 tumors of the PR were studied by comparative genomic hybridization (CGH). Long-term follow-up was evaluated for all patients.

Results: The study group included 6 pineal parenchymal tumors (PPT), one pineal cyst, 6 pineal germ cell tumors (GCT), 2 pilocytic astrocytomas, a plexus papilloma, a neuroendocrine as well as a solitary fibrous tumor. 15 patients were male, 3 female with a mean age of 33.25 years (ranging from 0–67 years). Postsurgical follow-up was 102.7 ± 10.4 months. 15.8% had tumor relapse, significantly reducing overall survival (OS) in these patients (p=0.02). Mean OS of patients suffering from tumor relapse was 96 months compared to 120 months for patients without recurring tumors. Overall, 4 out of 18 patients died, three of them diagnosed with pineoblastoma °IV. Independent on tumor histology, neither radiation nor chemotherapy showed a significant impact on OS, respectively. PPT revealed gains to 12q and 16p in 3 out of 5 tumors. 2 out of 4 pineoblastomas °IV had gain of whole chromosome 17 and at 8q, as well as losses to 13q. Germinomas showed common disbalances with gains of 12q and loss of 13q in 3 out of 4 tumors. The mature teratomas resembled those cytogenetic aberrations seen in germinomas, demonstrating gains of 1q, 7q, 12q, 16p, 17q, and 22q, and losses to 9p and 13q. Both pilocytic astrocytomas WHO °I revealed gains of 7q, 16p as well as whole chromosome 17. Plexus papilloma was characterized by gains to 7q, 12, 14q, 15q, 19p and 21q. Solitary fibrous tumor of the PR showed gains on chromosomes 7, 9q, 16p, 17, 22q and losses on chromosome 13q. The neuroendocrine tumor of the PR revealed most cytogenetic net changes of all analyzed tumors, gains were seen on 5, 7, 8, 9, 12p, 12q, 21q, 22q, and losses on 1, 2, 10, 13q, 14q, 15q, 18, 20.

Conclusions: Next to adding new clinical information on treatment strategies and outcome of patients with rare tumors of the PR, we here, for the first time, describe chromosomal changes in pilocytic astrocytoma WHO °I as well as in neuroendocrine tumor and solitary-fibrous tumor of this region.