Ito Tamio, Sato Kenichi, Ozaki Yoshimaru, Asanome Taku, Nakamura Hirohiko, Tanaka Shinya, Kimura Taichi, Kanno Hiromi
Department of Neurosurgery, Brain Tumor Center, Nakamura Memorial Hospital.
No Shinkei Geka. 2016 Jun;44(6):481-7. doi: 10.11477/mf.1436203314.
In benign pineal parenchymal tumors (PPTs), namely, pineocytoma(PC)and PPT of intermediate differentiation (PPTID), cytologic pleomorphism has occasionally been found;however, it is controversial as to whether the presence of pleomorphic cells leads to upgrading of tumors. We experienced a rare case of pleomorphic PPT in an elderly woman and compared it with a retrospective series of 12 PPTs (PC:3, PPTID:6, pineoblastoma[PB]:3)to evaluate the correlation between pleomorphism and the malignancy grade. CASE AND MATERIALS: A 76-year-old woman presented with gradual cognitive deterioration and gait disturbance. Gadolinium-enhanced magnetic resonance imaging(Gd-MRI)revealed a small, enhanced tumor in the pineal gland with marked hydrocephalus. Endoscopic tumor biopsy and third ventriculostomy were performed simultaneously. The tumor was soft, pinkish, and slightly hemorrhagic. After the biopsy, the patient underwent gamma knife radiosurgery.
The PPT presented with areas of tumor cells forming pineocytomatous rosettes and areas of giant and multinucleated cells with hyperchromatic nuclei. Neither mitosis nor necrosis was observed. The tumor cells were positive for synaptophysin(SYN)and neurofilament(NF), but negative for glial fibrillary acidic protein(GFAP)and oligodendrocyte lineage transcription factor 2 (Olig2). The MIB-1 labeling index(LI)was 8.1%. There was no difference in the MIB-1 LI between pleomorphic and non-pleomorphic areas. All the 12 PPTs were immunopositive for the neuronal markers SYN and NF. The MIB-1 LI was 0% in PC, 3.5% in PPTID, and 10.5% in PB. The proliferative potential was correlated with the WHO grade. From these findings, the final diagnosis of this pleomorphic case was PPTID grade II, not PC, because the MIB-1 LI was relatively high, even though some tumor cells were forming pineocytomatous rosettes.
Although cytologic pleomorphism in PPTs is generally considered not to be correlated with the malignancy grade, the final pathological diagnosis should be determined while considering the proliferative potential.
在良性松果体实质肿瘤（PPTs），即松果体细胞瘤（PC）和中间分化型松果体实质肿瘤（PPTID）中，偶尔会发现细胞多形性；然而，多形性细胞的存在是否会导致肿瘤分级升高仍存在争议。我们遇到了一例老年女性罕见的多形性PPT病例，并将其与回顾性收集的12例PPTs（PC：3例，PPTID：6例，松果体母细胞瘤[PB]：3例）进行比较，以评估多形性与恶性程度之间的相关性。
一名76岁女性，出现逐渐加重的认知功能减退和步态障碍。钆增强磁共振成像（Gd-MRI）显示松果体区有一个小的强化肿瘤，并伴有明显的脑积水。同时进行了内镜下肿瘤活检和第三脑室造瘘术。肿瘤质地柔软，呈粉红色，有轻微出血。活检后，患者接受了伽玛刀放射外科治疗。
该PPT表现为肿瘤细胞形成松果体细胞瘤性菊形团的区域以及含有核深染的巨细胞和多核细胞的区域。未观察到有丝分裂和坏死。肿瘤细胞突触素（SYN）和神经丝（NF）呈阳性，但胶质纤维酸性蛋白（GFAP）和少突胶质细胞谱系转录因子2（Olig2）呈阴性。MIB-1标记指数（LI）为8.1%。多形性区域和非多形性区域的MIB-1 LI无差异。所有12例PPTs对神经元标记物SYN和NF均呈免疫阳性。PC的MIB-1 LI为0%，PPTID为3.5%，PB为10.5%。增殖潜能与世界卫生组织（WHO）分级相关。基于这些发现，该多形性病例的最终诊断为II级PPTID，而非PC，因为尽管一些肿瘤细胞形成了松果体细胞瘤性菊形团，但MIB-1 LI相对较高。
尽管一般认为PPTs中的细胞多形性与恶性程度无关，但最终病理诊断应在考虑增殖潜能的同时确定。
