title: Clinicopathologic study of pineal parenchymal tumors of intermediate differentiation.
abstract: OBJECTIVE
  Pineal parenchymal tumors of intermediate differentiation (PPTID) are extremely rare tumor entities, and only limited data are available regarding their pathologic features and biologic behaviors. Because grading criteria of pineal parenchymal tumors (PPTs) have yet to be established, the treatment strategy and prognosis of PPTIDs remain controversial. We describe the clinicopathologic study of six patients with PPTID and compare responses for the treatment and prognosis with cases of pineocytoma (PC) and pineoblastoma (PB). From this analysis, we attempt to clarify the treatment strategy for PPTIDs.
  
  
  METHODS
  This study included 15 patients with PPTs, consisting of 6 PCs, 6 PPTIDs, and 3 PBs. We focused on the 6 patients with PPTIDs. All PPTID cases were treated surgically, and radiotherapy and chemotherapy were administered as adjuvant therapies in some cases. We have earlier reported the histopathologic study (Neuropathology 32:647-653, 2012). Briefly, we examined mitotic figures and necrosis by hematoxylin-eosin staining and immunohistochemical markers such as neuronal markers (synaptophysin, neurofilament (NF), and neuronal nuclear antigen), and an MIB-1 labeling index was determined.
  
  
  RESULTS
  In the PPTID cases, the extent of resection was variable and the recurrence rates among patients varied according to stage and treatment. All PC patients underwent total resection with no recurrence. All PB patients underwent resection and adjuvant therapy with radiotherapy and chemotherapy. There were no recurrences in patients with PC or PB. The results of histopathologic findings have been already reported as mentioned above. Briefly, the results indicated no mitotic figure or necrosis in any of the six cases of PPTID, but those features were observed in PB cases. All cases even including PC and PB were immunopositive for neuronal markers. The MIB-1 labeling index of PPTID was 3.5%, whereas it was 0% in PC and 10.5% in PB.
  
  
  CONCLUSIONS
  Good radiosensitivity of PPTIDs was observed in our series. Because there are cases with discrepancies between images and pathologic findings, it is very difficult to determine the proper treatment strategy for PPTIDs. Proliferative potential was correlated with World Health Organization grade, although the immunoreactivity of neuronal markers did not correlate with the histologic grade.
authors: Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital, Sapporo, Japan. Electronic address: titoh@med.nmh.or.jp.
authors: Tamio
authors: T
authors: Ito
authors: Department of Cancer Pathology, Hokkaido University School of Medicine, Sapporo, Japan.
authors: Hiromi
authors: H
authors: Kanno
authors: Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital, Sapporo, Japan.
authors: Ken-ichi
authors: K
authors: Sato
authors: Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital, Sapporo, Japan.
authors: Mitsuteru
authors: M
authors: Oikawa
authors: Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital, Sapporo, Japan.
authors: Yoshimaru
authors: Y
authors: Ozaki
authors: Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital, Sapporo, Japan.
authors: Hirohiko
authors: H
authors: Nakamura
authors: Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors: Shunsuke
authors: S
authors: Terasaka
authors: Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors: Hiroyuki
authors: H
authors: Kobayashi
authors: Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors: Kiyohiro
authors: K
authors: Houkin
authors: Department of Cancer Pathology, Hokkaido University Hospital, Sapporo, Japan.
authors: Kanako
authors: K
authors: Hatanaka
authors: Sapporo Azabu Neurosurgical Hospital, Sapporo, Japan.
authors: Jyun-ichi
authors: J
authors: Murata
authors: Department of Cancer Pathology, Hokkaido University School of Medicine, Sapporo, Japan.
authors: Shinya
authors: S
authors: Tanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers; D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D002454:Cell Differentiation; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017567:Karnofsky Performance Status; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010870:Pineal Gland / Q000473:pathology* / Q000601:surgery; D010871:Pinealoma / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D011379:Prognosis; D014696:Ventriculostomy / Q000379:methods; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: MIB-1 labeling index; Neuronal marker; PPTID; Pineal parenchymal tumor; Radiotherapy