Peripheral primitive neuroectodermal tumour – a rare cause of a popliteal fossa mass: A case report and review of the literature

A literature review of peripheral primitive neuroectodermal tumours, illustrated with an index case report describing an 80-year-old woman who presented with a mass in the left popliteal fossa, is reported. An excision biopsy was performed, revealing a possible peripheral primitive neuroectodermal tumour as the primary pathology. Normally confined to the chest wall and axial soft tissues of children and young adults, reports of this tumour existing in other areas and in the elderly population are scarce.     

Primary spinal primitive neuroectodermal tumor: A single center series with literature review

Context: Primary spinal primitive neuroectodermal tumor (PNET) of the central nervous system has a low incidence. The intraspinal case is very rare. Around 30 cases have been reported so far. We summarized the cases of primary spinal PNET available in the database of our institute, either intramedullary or extramedullary cases. Then we did literature review of the same disease.Findings: There were eight cases of primary spinal PNET available in our database, with one intramedullary case and seven extramedullary cases. Surgical resection was performed. The histology diagnosis was PNET. Peri-operative image examinations of the whole central nervous system (CNS) were performed to exclude tumors other than spinal cord origin. Then during literature review, 33 reports of the disease were included. The pre-operative diagnosis rate was low. The disease had a high recurrence rate and poor prognosis given available treatment.Conclusion: Primary spinal primitive neuroectodermal tumor is of high malignancy. Little is known due to its quite low incidence. The prognosis is poor due to lacking of effective treatment strategy. Present treatment strategy is referred to other common CNS malignancies like glioma. Further investigation of the disease is necessary.     

Primitive neuroectodermal tumor of the kidney: A rare entity

Primitive neuroectodermal tumor (PNET) is usually aggressive and rapidlyprogressing and metastasizing tumor. Occurrence of the this type of tumorin the kidney is considered as unusual, and few cases have been reportedso far. We present a PNET arising from the kidney in a 23-year-old femalepatient.     

Primary primitive neuroectodermal tumor (PNET) of the kidney with venous thrombus

Primitive neuroectodermal tumors of the kidney are rare, the diagnosis usually being made at histopathology. A young adult presented with a painful left renal mass. CT Scan of the abdomen revealed a large necrotic tumor of the left kidney. At surgery the patient was found to have a venous thrombus confined to the renal vein. Radical nephrectomy was done. Histopathology showed a round cell neoplasm with typical Homer Wright rosette formation and positive staining for neuron specific enolase (NSE) and MIC-2 on immunohistochemistry. The patient is undergoing multidrug chemotherapy and is alive and well at a follow up of nine months.     

泌尿系统原发性原始神经外胚层瘤临床病理分析

目的 探讨泌尿系统原发性原始神经外胚层瘤(primitive neuroectodermal tumor,PNET)的临床病理特征、免疫学表型、治疗方法及预后.方法 回顾性分析3例泌尿系统原发性PNET患者资料.3例均为男性,年龄分别为29、32和75岁.2例原发于肾脏,1例原发于膀胱.2例肾肿瘤大小分别为7.7 cm×6.2 cm和12.6 cm×9.4 cm,影像学检查提示肿瘤边界尚清,内部回声欠均匀.膀胱肿瘤大小为10.0 cm×10.0 cm,影像学检查提示膀胱壁不规则增厚,其内密度不均匀.2例肾肿瘤行肿瘤根治术,膀胱肿瘤行血块取出术及肿瘤活检术.结果 光镜下,瘤细胞为形态一致的小圆形或卵圆形,被纤维结缔组织分隔成实性片状或巢状,并形成假菊形团或Homer-Wright菊形团,核分裂象多见.免疫组化标记:3例肿瘤CD99、突触素和波形蛋白均为阳性.1例肾肿瘤Ki67阳性率＜5%,另1例80%阳性.3例病理诊断均为PNET.例1肾肿瘤患者未行化疗,于术后14个月复发死亡;例2肾肿瘤及例3膀胱肿瘤患者术后予以化疗,分别于术后4、6个月死亡.结论泌尿系统原发性PNET是一种少见的高度恶性软组织肿瘤,诊断主要依据病理形态学特征及免疫组化标记.目前治疗方法主要是手术加放、化疗.

Abstract：

Objective To explore the clinico-pathological features, immunophenotype, treatment and prognosis of urologic primary primitive neuroectodermal tumor (PNET). Methods The clinical data of 3 patients with urologic PNET were analyzed retrospectively. All patients were male, aged 29, 32 and 75 years respectively. Two of the lesions were located in the kidney, and the third was located in the bladder. The sizes of renal tumors were 7.7 cm×6.2 cm and 12.6 cm×9.4 cm respectively. Imaging examinations revealed a well-defined mass with inhomogeneous echo inside. The size of bladder tumor was 10.0 cm×10.0 cm. CT scan demonstrated irregular thickening of the bladder wall, and the density of the wall was inhomogeneous. In the 2 cases of renal PNET radical surgery was performed, while an emergency palliative surgery to remove a blood clot and biopsy were performed in the bladder PNET case. Results In light microscope, the tumors were characterized by uniform small round or oval cells and nest-like or dense sheet structures surrounded by sparse fibrovascular stroma. Homer-Wright rosettes or pseudorosettes were observed, as well as mitoses. Immunohistochemical study revealed that all cases showed positive staining for CD99, synaptophysin and vimentin. One of the renal tumor cells showed positive for CD56, and the other renal tumor and urocystic tumor cells were focally positive for chromogranin A. Additionally, in 1 of the cases of renal tumor there was a high positive rate of 80% for Ki67 staining while the other case showed less than 5%. All 3 cases were eventually diagnosed as PNET. The first renal tumor case was not treated with radiotherapy and chemotherapy postoperatively, and the patient died of recurrence 14 months after surgery. Both the second renal tumor case and the bladder tumor case underwent chemotherapy postoperatively, and they died 4 and 6 months after surgery respectively. Conclusions The urologic primary PNET is a very rare, highly malignant soft tissue tumor, and the diagnosis must be based on pathologic findings and immunohistochemical phenotypes. The multimodal treatment for urologic primary PNET consists of surgery, chemotherapy and radiotherapy.     

卵巢原始神经外胚层肿瘤1例

正患者女,26岁,1个月前无明显诱因出现恶心、呕吐及频繁嗳气,呕吐物为胃内容物,伴下腹胀、尿频、便秘。近半个月出现间断下腹坠痛3次,每次持续约1h。生命体征平稳,体质量减轻20余斤。体格检查:盆腔可触及实性包块,上界达脐部,有轻压痛。血清肿瘤标记物:CA125 258.10 U/ml,CEA、CA199、AFP正常。MR检查:子宫上方见大小约17.7cm×10.4cm×14.6cm肿块,T1WI呈等及稍低信号,T2WI呈大部     

Renal Ewing’s sarcoma/primitive neuroectodermal tumor (PNET): a case series of 7 patients and literature review

BackgroundPrimitive neuroectodermal tumor (PNET) is a rare kind of sarcoma that is primarily found in the kidney and has a very poor prognosis. Here, we review and summarize the clinical data of patients with renal PNET in our center and follow up the patients for survival status. Although the current literature suggests that chemotherapy may benefit the survival of these patients, the information from our center suggests that this may not be the case.MethodsWe retrospectively analyzed the clinical data of patients with renal PNET diagnosed pathologically at Peking University First Hospital from January 1, 2007, to January 1, 2018. All of the patients were followed up for survival status.ResultsSeven patients with renal PNET were found. The ratio of males to females was 6:1. The median age was 29 years (21–72 years) at the time of diagnosis. The preoperative imaging examination showed a large renal mass protruding outwards from the renal contour, with internal necrosis and hemorrhage. Six/7 patients were diagnosed with distant metastasis or retroperitoneal lymph node metastasis. The main clinical manifestations of patients were pain (5/7) and fever (3/7). In immunohistochemistry, all patients’ samples were CD99 positive. All patients died in our follow-up, with an average overall survival (OS) of 12.09 months (1.90–26.77 months).ConclusionsAs a rare renal tumor, renal PNET has a propensity to occur in young males. Most patients have distant metastasis when they are diagnosed, and the prognosis is very poor. Effective treatments are urgently needed.     

腹膜后原始神经外胚层瘤／尤因肉瘤一例报告并文献复习

目的总结腹膜后原始神经外胚层瘤／尤因肉瘤（PNET／EWS）的临床及组织病理特点,探讨其诊疗方法及预后情况。方法分析1例罕见的腹膜后PNET／EWS的临床特征、组织病理学特点以及诊断、治疗方法,同时复习近年来的国内外相关文献。结果患者当地医院行左肾切除＋左腹膜后肿物部分切除,术后病理示PNET,并在当地医院行化疗。手术后4个月肿瘤复发,再次行手术切除并行化疗,1年后检查发现肿瘤再复发。结论腹膜后PNET／EWS是一种小圆形细胞组成的恶性肿瘤。诊断时应与其他腹腔和腹膜后软组织肿瘤相鉴别。治疗以手术切除为主,化疗效果不肯定。本病有侵袭性的临床过程,远处转移早,经常局部复发和区域淋巴结转移,肺、肝、骨和骨髓转移,预后较差。     

儿童阴茎原始神经外胚层肿瘤/尤文氏瘤1例并文献复习

目的:探讨原发于阴茎的原始神经外胚层肿瘤/尤文氏瘤(PNET/Ewing's sarcoma)的临床表现、病理特点、治疗方法。方法:分析本院收治的1例5岁患儿原发于阴茎的PNET/EWS患者的病例资料进行文献复习。结果:病理表现为小圆细胞恶性肿瘤,免疫组化结果显示CD99(+),分子生物学检查:EWS荧光原位杂交可见易位,符合原始神经外胚层肿瘤/尤文氏肉瘤诊断,该患者经过病理确诊为阴茎PNET/EWS,经45周化疗和局部放疗,瘤灶缩小。目前停药3个月。结论:原发阴茎PNET/EWS极罕见,临床症状无特异性,以阴茎增大伴疼痛为主,免疫组化及分子生物学检查有助于对PNET/EWS的确诊。     

Organ-confined primitive neuroectodermal tumor arising from the kidney

Primitive neuroectodermal tumor (PNET) of the kidney is a rare entity with high malignant potential. Of the reported cases of renal PNET, patients presented with metastatic disease and had a poor response to therapy. The authors describe a rare case of an organ-confined primary PNET arising from the kidney in a 16-year-old girl who presented with vague abdominal pain. Tumor behavior and treatment modalities are discussed.     

肾上腺原始神经外胚叶肿瘤1例报告并文献复习

目的探讨肾上腺原始神经外胚叶肿瘤的临床表现、病理特点、治疗方法及预后。方法分析1例右侧肾上腺原始神经外胚叶肿瘤患者的病例资料并复习相关文献。结果手术根治切除肾上腺肿瘤,病理诊断为肾上腺原始神经外胚叶肿瘤,术后采取辅助大剂量放疗,半年后右侧腹壁肿瘤转移,再次手术切除转移灶,术后2月复查B超见右肾上腺区肿瘤复发,患者1年后死亡。结论肾上腺原始神经外胚叶肿瘤临床罕见,病理及免疫组化是原始神经外胚叶肿瘤确诊的金标准。手术是早期患者首选的治疗方法,晚期患者可以辅助联合化疗,对预后尚没有评估依据。     

Precocious puberty because of a pancreatic neuroectodermal tumor

Primitive neuroectodermal tumors (PNETs) are uncommon, representing approximately 1% of all sarcomas. Pancreatic PNETs have been reported only 12 times in the literature. This report presents the first case of a patient with a PNET exhibiting precocious puberty. The clinical presentation, surgical management, and pathology of this rare pancreatic PNET found in a 2-year-old girl with precocious puberty are discussed.     

输尿管原始神经外胚叶肿瘤1例

正患者女,44岁,因"无痛性肉眼血尿3个月"入院。专科查体未见明显异常。尿常规红细胞计数1 184/μl(参考范围0～10/μl)。超声:右侧输尿管膀胱壁内段增粗呈稍低回声,直径约0.8cm,边界清晰,于膀胱三角区呈结节状凸入膀胱,右侧输尿管稍扩张;CDFI示病变内血流信号丰富。MRI:右侧输尿管壁内段壁增厚,末端呈结节状凸入膀胱,约0.9cm×1.5cm,右侧输尿管稍扩张,直径约0.9cm;T2-频率选择反转恢复衰减序列(spectral attenuated inversion recovery,SPAIR)图像示病变呈     

Primitive neuroectodermal tumor/Ewing''s sarcoma with long-term follow-up.

We have reported a case of primitive neuroectodermal tumor/Ewing’s sarcoma (PNET/EWS) in a 32-year-old female who had had no symptoms until the tumor was detected in a general examination after she gave birth. Chest X-ray showed a well-defined, rounded mass in the left lower lung field. Computed tomographic scan of the chest revealed a distinct mass adjacent to the anterolateral thoracic wall. The macroscopic findings had shown a well-capsulated tumor with a stalk emanating from the thoracic wall. PNET/EWS was histologically diagnosed. The tumor was composed of atypical, small round cells. It stained positively with antibodies to the MIC2 gene product. Postoperative adjuvant radiotherapy of 50 Gy was performed. Adjuvant chemotherapies were not performed. Four years later, a small recurrent nodule in the left lung was surgically resected. Since her initial diagnosis, the patient has survived for seven years; in the three years since her second surgery, she has had no other recurrence or metastasis.     

A primitive neuroectodermal tumor on the face: case report

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma. The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin's tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face. PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation. It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.     

肾外周原始神经外胚层肿瘤一例报告

正外周原始神经外胚层肿瘤(peripheral primitive neuroectodermal tumor,pPNET)累及肾脏者临床罕见,多发生于儿童及青壮年,其组织病理及免疫组化、遗传特征等有特征性表现,预后较差,易误诊为肾细胞癌,确诊依靠术后病理。现报道我院诊治的1例肾p PNET,并结合相关文献进行分析。临床资料患者男性,38岁,于2014年4月因"左腰部不适伴发热、乏力1个月"就诊,无肉眼血尿。查体:左上腹脐上2横指可扪及肿物。彩超提示左肾回声不均实性肿物。CT平扫+强化示左肾下极直径12 cm的囊实性占位,     

A case of primitive neuroectodermal tumor of the kidney]

A primitive neuroectodermal tumor (PNET) is a solid tumor originating from the neural crest. This tumor is known to occur in the central nervous system and soft tissue, but recently determined to also invade the kidney. Although primary renal PNET is very rare, we encountered a case of primary renal PNET with multiple lung metastasis. This case was a 35-year-old man with a chief complaint of macroscopic hematuria, which he noticed in January 1996. He was hospitalized because of right renal tumor detected with ultrasonography. On CT scan, a low-density solid tumor with a maximum diameter of 8 cm was visualized in the right kidney. Low-signal and high-signal tumorous lesions were demonstrated in the same region on T 1-weighted and T 2-weighted MR images, respectively. Then right radical nephrectomy was performed on Feb. 5, 1996. On histopathological observation, the tumor was composed of small tumor cells with solid growth. Immunohistochemical staining revealed that the tumor was positive for CD 99. Thus our final diagnosis was primary right renal PNET. Although 2 metastatic lesions with a diameter of about 1 cm were observed in the right lower lung before the time of surgery, pulmonary metastatic lesions markedly increased in number 3 months after surgery. Thus we initiated CAP chemotherapy with cyclophosphamide, doxorubicin, and CDDP. After 3 cycles, pulmonary metastatic lesions disappeared at CT scan, indicating complete remission. However, a tumor with a maximum diameter of about 10 cm recurred in the retroperitoneum 7 months after complete remission. Although 2 cycles of CAV/PE therapy with cyclophosphamide, doxorubicin, vincristine, CDDP, and VP-16 were performed following resection of the retroperitoneal tumor, he showed no response and decreased 24 months after surgery.     

Primitive neuroectodermal tumor of the adrenal gland

We report a rare case of primitive neuroectodermal tumor arising from adrenal gland in adulthood, diagnosed preoperatively as having non-functional adrenocortical adenoma. Laparoscopic adrenalectomy was performed. Immunohistological examination revealed the definite diagnosis as primitive neuroectodermal tumor of the adrenal gland. Although primitive neuroectodermal tumor is a highly malignant neoplasm, there is no evidence of local recurrence and distant metastasis 16 months after surgery.