Pineocytoma with malignant transformation to pineal parenchymal tumor with intermediate differentiation and leptomeningeal dissemination after subtotal tumor resection and adjuvant radiotherapy

Pineocytoma is a rare tumor. It is rare for pineocytoma to present as leptomeningeal metastasis. We present a rare case of pineocytoma with malignant transformation and leptomeningeal metastasis after subtotal tumor resection and adjuvant radiotherapy. This case was a 58-year-old male with an unsteady gait for 2 months. Enhanced brain magnetic resonance imaging revealed a heterogeneous mass involving the pineal region. The initial pathological diagnosis of pineocytoma was confirmed after subtotal tumor resection. Two years after adjuvant radiotherapy to the primary site, the magnetic resonance imaging showed C2 and T2 metastatic lesions, with the final pathological diagnosis being pineal parenchymal tumor (PPT) with intermediate differentiation after the removal of T2 intramedullary tumor. After that adjuvant radiotherapy at the cervical and thoracic spinal cord was completed. There was no recurrence of the tumor 1 year after the radiotherapy. We report a rare case of pineocytoma with malignant transformation to PPT with intermediate differentiation and leptomeningeal dissemination.

Upfront Stereotactic Radiosurgery for Pineal Parenchymal Tumors in Adults

OBJECTIVE: Pineal parenchymal tumors (PPTs) in adults are rare, and knowledge regarding their optimal management and treatment outcome is limited. Herein, we present the clinical results of our series of PPTs other than pineoblastomas managed by stereotactic radiosurgery (SRS) at upfront setting. METHODS: Between 1997 and 2014, nine consecutive adult patients with the diagnosis of PPTs, either pineocytoma or pineal parenchymal tumor of intermediate differentiation, were treated with SRS. There were 6 men and 3 women. The median age was 39 years (range, 31-53 years). All of the patients presented with symptoms of hydrocephalus. Endoscopic third ventriculostomy and biopsy was done for initial management. After histologic diagnosis, patients were treated with Gamma Knife with the mean dose of 13.3 Gy (n=3) or fractionated Cyberknife with 32 Gy (n=6). RESULTS: After a mean follow-up of 78.6 months (range, 14-223 months), all patients were alive and all of their tumors were locally controlled except for one instance of cerebrospinal fluid seeding metastasis. On magnetic resonance images, tumor size decreased in all patients, resulting in complete response in 3 patients and partial response in 6. One patient had experienced temporary memory impairment after SRS, which improved spontaneously. CONCLUSION: SRS is effective and safe for PPTs in adults and can be considered as a useful alternative to surgical resection at upfront setting.

Pineal Parenchymal Tumor of Intermediate Differentiation with Gangliocytic Differentiation: A Case Report

A 49-year-old man presented with an extremely rare case of pineal parenchymal tumor with gangliocytic cells, manifesting as progressive gait disturbance and urinary incontinence lasting for one year. Brain MRI revealed a homogenously enhancing mass, measuring 3.5x2.7 x1.7 cm, in the pineal body. The mass compressed the deep cerebral vein with superior displacement, which caused mild obstructive hydrocephalus. Histological examination revealed lobular structures consisting of isomorphic small round cells with stippled chromatin and clear cytoplasm, and less cellular areas having large pleomorphic cells and ganglioid cells. Mitotic figures and tumor necrosis were not evident. Immunohistochemically, the neoplastic cells were positive for neuronal markers (neuron-specific enolase, neurofilament, NeuN and synaptophysin), but not for glial fibrillary acidic protein or S-100. Especially, neurofilament showed diffuse interstitial immunoreactivity with accentuation in a few gangliocytic cells and Ki-67 labeling index (2.5%) was low. Therefore, this case was diagnosed as pineal parenchymal tumor of intermediate differentiation with gangliocytic differentiation.

Gamma Knife Surgery for the Pineal Region Tumors

OBJECTIVE: Gamma Knife Surgery(GKS) for the management of pineal region tumors is challengeable strategy as direct access to this area is not easy. The experiences of pineal region tumor patients treated with GKS were analyzed to evaluate the effectiveness. METHODS: Seven patients with tumors in the pineal region were treated with GKS between September 1998 and May 2005. The histological diagnosis were pineal parenchymal tumor (2 patients), low-grade astrocytoma (2 patients), immature teratoma (1 patient), and choriocarninoma (1 patient). One patient was diagnosed as metastatic brain tumor based on histological diagnosis for primary site and brain imaging study. The median marginal dose was 15Gy (range; 11~20) at the 50% isodose line. The median target volume was 2.5cm3 (range; 0.8~12.5). The median clinical follow up period was 29 months (range; 13~93) and the median radiological follow up period was 18 months (range; 6~73). RESULTS: Tumor volume measured in follow-up images showed reduction in six patients, disappearance in one. No adverse effect due to GKS was found during the follow-up period . The performance status was preserved in all patients except one who died due to progression of primary cancer in spite of controlled metastatic brain lesion. CONCLUSION: Gamma Knife Surgery can be applied to pineal region tumors irrespective of their histology whenever surgery is not indicated.