Primary primitive neuroectodermal tumor of the ovary: a case report

Ovarian germ cell tumours having neuroectodermal cells, growing in patterns reminiscent of tumours of the central nervous system are rare. We report a case of primary primitive neuroectodermal tumor(PNET) of the ovary detected soon after pregnancy.     

Primary renal primitive neuroectodermal tumor

Primitive Neuroectodermal Tumor of the kidney is a rare entity. Very few cases of primary renal PNET have been reported to date. Most literature about rPNET is isolated case reports. We report a case of rPNET in a 39-year-old male with a pre-operative diagnosis of renal cell carcinoma with renal vein thrombosis. The patient underwent radical nephrectomy with thrombolectomy, and histopathological examination revealed a highly aggressive tumor composed of monotonous sheets of round cells. Tumor cells were positive for CD 99 and FLI-1, hence confirming the diagnosis of Primitive Neuroectodermal Tumor. Post-surgery, patient was given VAC/IE-based adjuvant chemotherapy. In view of highly aggressive nature of this tumor, prompt diagnosis and imparting effective chemotherapy regimen to the patient is required, and it is important to differentiate PNET from other small round-cell tumors because of different therapeutic approach.KEY WORDS: Chemotherapy, immunohistochemistry, kidney, primitive neuroectodermal tumor     

原发椎管内外周型原始神经外胚层肿瘤2例

目的探讨椎管内原发外周型原始神经外胚层肿瘤的临床特点、诊断、病理表现和治疗进展。方法分析2例经影像学、手术和病理检测证实的椎管内原始神经外胚层肿瘤,回顾相关文献,总结其临床特点。结果 2例病变术前行MRI检查呈等T1WI和等T2WI信号,增强后明显强化;镜下部分切除病变,术后病理检查提示均为外周型原始神经外胚层肿瘤,术后行放疗和化疗,分别随访13和10个月。结论椎管内原始神经外胚层肿瘤发病率低,好发于青少年,影像学无明显特异性,病理检查是可靠的诊断依据,预后较差。     

Primary primitive neuroectodermal tumor of the cauda equina

Primitive neuroectodermal tumors (PNETs) are aggressive neoplasms composed predominantly of undifferentiated cells that show evidence of neural differentiation. Although their classification has been controversial, PNETs are well recognized primary tumors of both central and peripheral nervous systems. PNETs must be distinguished from other round-cell tumors, including Ewing's sarcoma, lymphoma, rhabdomyosarcoma, and small cell carcinoma. Intraspinal PNETs are rare neoplasms that are usually metastatic in origin. We describe the eighth reported primary PNET of the cauda equina that developed in a 52-year-old man with no significant medical history. The tumor was characterized by Homer-Wright rosettes and immunoreactivity for CD99, glial fibrillary acidic protein, neuron-specific enolase S100, and synaptophysin. The anatomic location of primary intrathecal PNETs is important as those arising in the spinal cord develop in the central nervous system, whereas those arising in the cauda equina develop in the peripheral nervous system. The histogenesis of intrathecal PNETs may be multifactorial.     

骨原发性原始神经外胚层瘤临床病理学研究

目的 探讨骨原发性原始神经外胚层瘤(PNET)临床病理特点和鉴别诊断要点及组织发生。方法 观察与分析12例骨原发性PNET的临床特征、组织学特征及SP法免疫组化标记，并对其中4例进行电镜观察。结果 PNET好发于男性青少年[9～29(平均17．7)岁]的长骨。组织学特征：肿瘤由大小一致的、原始的小细胞弥漫分布，纤维性条索将其分隔成不规则片块状，可形成Homer—Wright菊形团。免疫组化标记：CD99阳性，NSE、Syn及S-100蛋白部分阳性，Vim均阳性表达。电镜下瘤细胞形态较原始，可见线粒体、发育不良及神经分泌颗粒。结论 该肿瘤是一种少见的、好发生于男性青少年、组织学形态原始的、向神经外胚层分化的、具有高度侵袭性生长的、预后不良的原发性骨肿瘤。     

Primary intraspinal primitive neuroectodermal tumor at conus medullaris

A primary intraspinal primitive neuroectodermal tumor is very rare, with only 24 cases having been reported in the literature. In general this type of tumor is treated with surgery followed by radiotherapy and chemotherapy; however, the prognosis still remains poor. The case of a primary intraspinal primitive neuroectodermal tumor, at the conus medullaris in a 17 year old male patient is presented. He had suffered from paraparesis, urinary difficulty and lower back pain of 1 month duration. A thoracolumbar MRI demonstrated a 2 x 2 x 8 cm isointense intraspinal mass, on T1-weighted images, with strong contrast enhancement from the T11 to L2 level. There was no clinical or radiological evidence for the existence of an intracranial tumor. A histological examination revealed a small round cell tumor and immunohistochemical characteristics of PNET. The clinical, radiological and pathological features are discussed with a review of the literatures.     

外周原始神经外胚肿瘤／尤因肉瘤临床病理学

目的：研究原始神经外胚叶瘤（PNET）／尤因肉瘤的（EWS）的诊断,鉴别诊断。方法：41例病人按传统病理学分为3类,并用免疫组织化学两步法检测CD99,NSE,S－100蛋白,Syn,VIm,LCA,Des,Myo抗体的表达。结果：（1）41例病人有27例PNET,8例EWS和6例Askin瘤。（2）免疫表型,CD99有87．8％强阳性表达,NSE53．7％,S－100蛋白22％,Syn4.9%,vim41.5%,统计结果显示CD99强阳性表达与NSE,S-100蛋白,Syn,Vim强阳性表达差异有显著性（P＜0．01）。（3）,PNET,EWS,Askin瘤对各种抗体的阳性表达差异无显著性（P＞0．05）,结论：（1）PNET,EWS,Askin瘤属同一肿瘤家族,（2）用组织学,免疫组织化学可与其他小圆细胞肿瘤进行鉴别诊断。     

Primary malignant teratoma with a primitive neuroectodermal tumor component in thyroid gland: a case report

Teratomas comprise the most common extragonadal germ cell tumors in childhood. Most teratomas involving the thyroid are benign and occur in children. However, the adult cases reported are mostly malignant and commonly arise in the thyroid. We report a case of a 31-yr-old female with a huge neck mass. Pathologic examination revealed it to be malignant teratoma composed of primitive neuroepithelial tissue with primitive neural tubes and loose myxoid to fibrous immature mesenchymal stroma. The patient underwent extensive evaluation of the thyroid gland with computed tomography (CT) scan and positron emission tomography (PET) scan, which revealed no evidence of metastatic disease. She underwent total thyroidectomy with bilateral modified radical neck dissection, intensive chemotherapy and radiotherapy. At 22-months of follow-up, the patient has remained euthyroid and showed no evidence of recurrence. This is the first case, to our knowledge, of malignant thyroid teratoma with a exuberant primitive neuroectodermal tumor component in Korea.     

Ewing sarcoma/primitive neuroectodermal tumor of the kidney: a case report. Diagnosed by immunohistochemistry and molecular analysis

BACKGROUND: Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) of the kidney is a rare and aggressive tumor. It has a rapid clinical progression with early metastasis and death. Few cases with documented t(11;22) have been reported in the literature. CASE PRESENTATION: We report a case of EWS/PNET of the kidney in a 26-year-old woman with widespread metastasis at initial presentation. The tumor cells showed strong expression for CD99 and FLI-1 monoclonal antibodies and polyclonal antibodies and were negative for WT1 and numerous other markers. The diagnosis was subsequently confirmed by demonstrating t(11;22)(q24;q12) using cytogenetic karyotyping and fluorescence in situ hybridization. CONCLUSIONS: Due to the different prognosis and management between EWS/PNET and other primary renal neoplasms with similar morphology, a histopathologic diagnosis with extreme accuracy should be made. Cytogenetic analysis is an important supportive tool to immunohistochemistry in making the final diagnosis.     

Primary vulvar Ewing's sarcoma/primitive neuroectodermal tumor in a post-menopausal woman: A case report

Ewing's sarcomas/peripheral primitive neuroectodermal tumors (ES/pPNETs) are high-grade malignant neoplasms rarely found outside the skeletal system. Only 12 cases of vulvar ES/pPNET have so far been reported, all involving children or women of child-bearing age. We describe the case of a 52-year-old woman who was admitted to our hospital for the local excision of a 4 cm vulvar mass, originally thought to be a Bartholin's gland cyst. It was subsequently found to consist of small round cells positive for anti-CD99 antibody, thus suggesting a diagnosis of ES/pPNET. The demonstration of EWSR1 gene translocations by means of fluorescent in situ hybridization excluded small-cell carcinoma, squamous cell carcinoma of the small type, Merkel cell carcinoma, and lymphoblastic lymphoma. After surgery, the patient received six cycles of polychemotherapy and radiotherapy; she is still alive and well after 1 year of follow-up. Our findings underline the crucial role of molecular biology techniques in the differential diagnosis of small round cell tumors in these unusual locations.     

骨外Ewing肉瘤/外周原始神经外胚叶肿瘤的临床病理分析

目的探讨骨外Ewing肉瘤／外周原始神经外胚叶肿瘤的临床病理特征及诊断、鉴别诊断依据。方法18例骨外Ewing肉瘤／外周原始神经外胚叶肿瘤行常规病理检查及免疫组化染色,其中2例进行电镜检查。结果光镜显示肿瘤组织主要由小圆形或卵圆形细胞组成,免疫组化染色显示肿瘤细胞膜CD99强阳性,电镜显示肿瘤细胞质内有神经内分泌颗粒。结论骨外Ewing肉瘤/外周原始神经外胚叶肿瘤的诊断依赖病理特征,并需要与其他小细胞恶性肿瘤进行鉴别。