Extraosseous Ewing's sarcoma/peripheral primitive neuroectodermal tumour of the kidney: a case report and literature review.

BACKGROUND: Extraosseous Ewing's sarcoma/peripheral primitive neuroectodermal tumours(EWS/pPNETs) of the kidney are rare. Signs and symptoms are atypical in EWS patients. Presenting symptoms include haematuria, abdominal pain, or a palpable mass. A comprehensive review of the literature shows that it is difficult to make an accurate diagnosis based on physical examination alone. The imaging findings of EWS/pPNETs are nonspecific. We used contrast-enhanced ultrasound (CEUS) to diagnose an EWS/pPNET in our patient, which had never been reported previously to our knowledge. CASE PRESENTATION: This article reports the case of a 20-year-old female with an abdominal mass and gross haematuria for 1 month. The ultrasound revealed a hypoechoic mass with a clear margin at the lower pole in the left kidney. CEUS demonstrated signs of annular enhancement and heterogeneous enhancement of the tumour, and simultaneous wash-in was predominant. Computed tomography images showed an elliptical low-density tumour. The patient underwent a left kidney resection, and the pathological diagnosis was an EWS/pPNET. Twenty-one days after the kidney operation, the patient underwent 8 cycles of a CAV (vinorelbine, ifosfamide, epirubicin) + IE (isocyclophosphamide, etoposide) chemotherapy regimen. Subsequently, radiotherapy (dose: 45 Gy, radiation field:the tumour bed following surgical resection) was administered for nearly 30 days. The patient had no signs of local recurrence or metastasis within a follow-up of 4 years. CONCLUSIONS: As a radiation-free, inexpensive, convenient, and repeatable examination method, ultrasound was the primary choice for kidney examination. Early CEUS was helpful to make an accurate diagnosis. Surgery and adjuvant radiation or chemotherapy administered in a timely manner can prevent further deterioration.

Primitive neuroectodermal tumor of the pericardium: a case report and literature review.

BACKGROUND: The primitive neuroectodermal tumors (PNETs) are a family of highly malignant tumors with a multidirectional differential potential. The tumors are characterized by aggressive small round tumor cells that originate from the spinal cord of the central and sympathetic nervous systems. Cases involving the pericardium are extremely rare. Herein, we present a case of peripheral primitive neuroectodermal tumor (pPNET) that originated in the pericardium. CASE PRESENTATION: A 23-year-old woman presented with cough and progressive dyspnea for 1 month, followed by eyelid and facial edema for 10 days, without any apparent cause. Significantly elevated tumor markers were detected in her blood. A cardiac ultrasound revealed a 74 mm × 61 mm spherical mass that was attached to the left pericardium, as well as massive pericardial effusion. Positron emission tomography-CT (PET-CT) showed focal hypermetabolism in the left pericardium. Via histopathology and immunohistochemistry, the spherical mass was identified as PNETS. The patient was successfully treated with a combination of surgical resection via thoracotomy and postoperative chemotherapy, and she was disease-free for 7 years at follow-up. Unfortunately, at 7 years after the treatment, the patient's pPNET recurred. Positron emission tomography-MRI (PET-MRI) and 64-slice coronary CTA revealed that the aorta and multiple coronary arteries were involved. Subsequently, the patient refused a heart transplant and voluntarily left the hospital. CONCLUSIONS: This paper reports on a rare and recurrent case of PNET in the parietal pericardium. With respect to the different biologic characteristics and prognoses of pPNETs (compared to other known pericardium tumors), it is essential to consider this entity as a differential diagnosis in pericardium tumors.

Primary intracranial Ewing sarcoma/ peripheral primitive neuroectodermal tumor, an entity of unacquaintance: a series of 8 cases.

PURPOSE: The purpose is to highlight the primary intracranial (meningeal-based) occurrence of Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET). METHODS: This report is a collation of clinicopathological features of eight cases of molecularly and clinicoradiologically confirmed primary (non-metastatic) intracranial (non-osseous) meningeal ES/PNET. RESULTS: The age range was 1 to 33 years with a median age of 9 years. Male to female ratio was 0.6:1. All patients were diagnosed on the debulking surgical material (gross total resection, 2 cases; subtotal resection, 6 cases) and showed primitive embryonal histomorphology with diffuse membranous CD99 immunoexpression and EWSR1 gene rearrangement by fluorescence in situ hybridization. Seven of them showed a typical FISH pattern of split signals with break-apart probe, while one showed an unusual signal pattern of loss of green signals. EFT-2001 adjuvant protocol was followed along with focal radiotherapy (RT) in all cases (except case 8, full course of chemotherapy could not be completed). Two cases had local recurrence-one of them died of disease recurrence before the administration of further treatment. CONCLUSION: This series adds non-osseous intracranial site to the list of uncommon sites of occurrence for ES/PNET and more importantly emphasizes the need to be considered in a differential list of primary intracranial primitive embryonal tumors before embarking as primary central nervous system (CNS) embryonal tumor, NOS.

A rare entity of Primary Ewing sarcoma in kidney.

BACKGROUND: Ewing sarcoma (ES) or primitive neuroectodermal tumors (PNET) represents a spectrum of poorly differentiated and aggressive malignancies. It rarely arises from the kidney and accounts for less than 1% of renal mass. Given the uncharacteristic clinical symptoms and imaging features, renal Ewing sarcoma (RES) is often diagnosed by postoperative pathology. CASE PRESENTATION: Herein, we depicted a case of RES, which was administrated in our institution by chief complaints of intermittent left plank pain and palpable abdominal mass. We demonstrated the aggressive behavior of this renal malignancy and summarized its therapeutic modalities and outcomes. CONCLUSION: The diagnosis of RES relies on integrated analysis including histomorphology, immunohistochemical staining and confirmation of molecular-genetic testing. Despite the surgery and adjuvant therapy, optimized and potent therapeutic regimes are still urgently needed to improve the poor prognosis of RES.

Computed Tomography and Magnetic Resonance Imaging Characteristics of Peripheral Primitive Neuroectodermal Tumor: A Retrospective Analysis of 16 Cases.

PURPOSE: The aim of this study was to analyze the radiological features of peripheral primitive neuroectodermal tumor (pPNET). MATERIALS AND METHODS: The radiological and clinical findings for 16 patients with pPNETs were retrospectively reviewed. The 16 tumors were classified into 4 groups (meninges group, n = 4; spine group, n = 3; bone group, n = 5; soft-tissue group, n = 4), and clinical data, size, and common and unique CT/MRI characteristics were assessed. RESULTS: Peripheral primitive neuroectodermal tumors presented as large solid masses with aggressive extension into the neighboring tissue. Most tumors (11/16) presented with necrosis, and 5 of the 16 cases showed signs of hemorrhage. The "dural tail sign" was observed in the meninges and spine groups. The pPNETs of bone demonstrated bony destruction with spiculated periosteal reaction, and small nourishing vessels were found in tumors in the soft-tissue group. CONCLUSIONS: Peripheral primitive neuroectodermal tumor should be suggested as an important differential diagnosis when the tumor presents as a large, ill-defined solid mass with aggressive extension and significant enhancement.

Radiologic and clinicopathologic findings of peripheral primitive neuroectodermal tumors.

BACKGROUND: Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear. PURPOSE: To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition. MATERIAL AND METHODS: The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies. RESULTS: Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results. CONCLUSION: pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.

[Ewing sarcoma/primitive hepatic neuroectodermal tumor]. / Sarcoma de Ewing/tumor neuroectodérmico primitivo hepático.

Ewing sarcoma (ES) and primitive neuroectodermal tumor (PNET) belong to the group of neoplasms called small round cell tumors. PNETs have been divided into central and peripheral. ES and peripheral PNETs arise from bones, soft tissues, or peripheral nerves. We present a case of hepatic ES/PNET in a healthy man that began four months before consultation with abdominal symptoms and weight loss. Upper gastrointestinal endoscopy and laboratory tests revealed no notable findings. The abdominal tomography revealed an enlarged liver due to a solid lesion that involved all its segments with intravenous contrast enhancement and large areas of necrosis. It compressed and displaced neighboring structures. Core needle biopsy of the liver lesion was performed: small round cell neoplasm. Immunohistochemistry revealed negativity for CD45, CKA1/A3, chromogranin, synaptophysin, and cytokeratins CK7 and CK20. Dim CD56 expression and CD99, FLI-1, and NKX2 positivity. He underwent chemotherapy treatment with carboplatin and etoposide for 6 cycles with clinical improvement and tolerance. Control images showed reduction of the mass with involvement of the right hepatic lobe, involvement of the inferior vena cava, infiltration of the right adrenal gland and upper pole of the right kidney. He was referred to hepatobiliary surgery for surgical resection of the residual lesion. The patient rejected the proposed surgical procedure. Our objective is to highlight the clinical and histological diagnostic challenge of this entity that requires ruling out other clinical entities.

El sarcoma de Ewing (ES) y el tumor neuroectodérmico primitivo (PNET) pertenecen al grupo de neoplasias denominadas tumores de células pequeñas y redondas. Los PNET se dividen en centrales y periféricos. El ES y los PNET periféricos surgen del tejido óseo, de los tejidos blandos o nervios periféricos. Presentamos un caso de ES/PNET hepático en un hombre sano que inició cuatro meses antes de la consulta con síntomas abdominales y pérdida de peso. La endoscopia digestiva alta y la analítica no revelaron hallazgos relevantes. En la tomografía de abdomen se evidenció hígado aumentado de tamaño a expensas de lesión sólida que comprometía todos sus segmentos con realce al contraste endovenoso y grandes áreas de necrosis. Comprimía y desplazaba estructuras vecinas. Se realizó biopsia con aguja gruesa de la lesión hepática: neoplasia de células pequeñas y redondas. La inmunohistoquímica reveló negatividad para CD45, CKA1/A3, cromogranina, sinaptofisina y citoqueratinas CK7 y CK20. Expresión tenue de CD56 y positividad de CD99, FLI-1 y NKX2. Realizó tratamiento quimioterápico con carboplatino y etopósido por 6 ciclos con mejoría clínica y tolerancia al mismo. En imágenes de control se evidenció reducción de la masa con afección del lóbulo hepático derecho, compromiso de la vena cava inferior, infiltración de la glándula suprarrenal y polo superior del riñón derechos. Se remitió a cirugía hepatobiliar para resección quirúrgica de la lesión residual. El paciente rechazó el procedimiento quirúrgico. Nuestro objetivo es destacar el desafío diagnóstico clínico e histológico de esta entidad que obliga a descartar otras entidades clínicas.

Peripheral primitive neuroectodermal tumor: a case report.

BACKGROUND: Primitive neuroectodermal tumors are extremely rare and highly aggressive malignant small round cell tumors that arise from the primitive nerve cells of the nervous system or outside it. These tumors share similar histology, immunohistologic characteristics, and cytogenetics with Ewing's sarcoma. Peripheral primitive neuroectodermal tumors of the chest wall are rare malignant tumors seen in children and young adults. CASE PRESENTATION: We report a rare case of peripheral primitive neuroectodermal tumor in a 4-year-old Albanian girl with a mediastinal tumor and an unusual clinical presentation. She was initially treated for acute polyradiculoneuritis (Guillain-Barré syndrome) owing to pain, weakness in the lower limbs, and walking difficulty, as well as severe irritability. During the second week of treatment, the child began to experience dry cough, chest discomfort, and worsening dyspnea. Chest radiography, chest computed tomography, and contrast-enhanced computed tomography demonstrated a large mass in the right hemithorax that was derived from the posterior mediastinum with expansive growth in all directions and that shifted the mediastinal structures in the anterolateral left direction. Consequently, histopathology and immunohistochemical examination of the markers S-100, CD99, and Ki-67 showed that the tumor cells stained positively for S-100 and CD99. The proliferative index measured by Ki-67 was approximately 20%, which suggested primitive neuroectodermal tumor. CONCLUSIONS: Even though other diseases, including leukemia, lymphoma, and neuroblastoma, may be accompanied by musculoskeletal manifestations in children, other solid tumors, such as peripheral primitive neuroectodermal tumors, should be considered in the differential diagnosis in any child presenting with musculoskeletal symptoms.

Primitive Neuroectodermal Tumour of Subcutaneous Tissue Presenting as a Shoulder Lump: A Case Report.

Primitive neuroectodermal tumour is a poorly differentiated small round cell neoplasm that primarily affects children and is very rarely seen in adults. Peripheral primitive neuroectodermal tumours are rare compared to the central type and resemble soft tissue sarcoma. Primitive neuroectodermal tumours involving the subcutaneous tissue are rare and only a few cases involving the subcutaneous tissue of the anterior abdominal wall have been reported. However, no cases involving the subcutaneous tissue of the shoulder region have been reported. We report the case of a peripheral primitive neuroectodermal tumour arising from subcutaneous tissue of the right shoulder in a young adult. Keywords: case report; magnetic resonance imaging; neuroectodermal tumour; neuron-specific enolase; subcutaneous tissue.

Congenital primary primitive neuroectodermal tumor of the orbit in a newborn.

INTRODUCTION: Primitive neuroectodermal tumors arise from the progenitor cells of the neural crest, in the central nervous system or other peripheral locations. CASE PRESENTATION: We report a rare case of a congenital malignant tumor, diagnosed as a primary orbital primitive neuroectodermal tumor on histopathological examination. CONCLUSION: Multidisciplinary management with adjuvant chemotherapy needed for the management of these cases.

Primitive neuroectodermal tumor arising in the abdominopelvic region: CT features and pathology characteristics.

BACKGROUND: We analyze the computed tomography (CT) findings of a peripheral primitive neuroectodermal tumor (pPNET) arising in the abdominopelvic cavity and to improve understanding of the CT images of the tumor. MATERIALS AND METHODS: Twelve cases of pPNET confirmed by histopathology were analyzed retrospectively. Image characteristics of CT scanning were analyzed and compared with the pathology of the tumors. RESULTS: There were 8 males and 4 females with mean age of 34.5 years. Unenhanced CT images showed large heterogeneous and ill-defined or well-defined masses with multiple patchy hypodense areas. The average diameter was 9.8 cm (range 4.0-17.2 cm). Contrast-enhanced CT images showed variable heterogeneous contrast enhancement with multiple non-enhancement areas. 3 cases revealed metastasis and 4 cases invaded into adjacent organs. Pathology showed areas of degeneration and necrosis in all tumors. Cluster of differentiation 99 and neurone specific enolase were detected positive in 11 and 12 cases, respectively. CONCLUSIONS: In conclusion, pPNET in the abdominopelvic cavity likely affects young adults with a slight male preponderance and tend to be large and aggressive. Although CT findings are nonspecific and variable, a large ill-defined or well-defined heterogeneous mass with multiple patchy hypodense areas reflecting their cystic degeneration and necrosis on pathology examination may suggest the diagnosis of pPNET.

Primitive neuroectodermal tumor of the orbit in adults: a case series.

PURPOSE: To present the clinical, radiologic, and histopathologic features of orbital primitive neuroectodermal tumor (PNET) in 5 adult patients. METHODS: Retrospective case series of 5 adult patients with orbital PNET. Orbitotomy was performed in all cases. The authors report clinical findings, radiologic features, histopathology, immunohistochemical analysis, management, and outcomes for 5 patients with orbital PNET. RESULTS: Five adult patients presented with progressive unilateral proptosis and visual impairment. Common radiographic findings included a heterogeneous mass without associated destructive features, located in the superior and/or lateral orbit. Four cases demonstrated strong immunohistochemical staining for CD99 in a membranous pattern. One case required chromosomal analysis with fluorescence in situ hybridization to confirm the diagnosis. All patients received chemotherapy and/or orbital radiation with resolution of proptosis but no improvement of vision. One patient died of disease. CONCLUSIONS: To the authors' knowledge, this is the largest series of orbital PNET in adults. This tumor has an age demographic wider than previously believed and should be considered in the differential diagnosis of a hypercellular small round cell orbital tumor in both children and adults. Current treatment regimens are not standardized but typically use a similar approach to the treatment of Ewing sarcoma. Orbital PNET appears to have less propensity for metastasis compared with PNET in other locations. However, long-term aggressiveness remains to be proven.

Giant extraosseous Ewing sarcoma of the lung in a young adolescent female--a case report.

Extraosseous Ewing sarcoma is a rare soft tissue tumour that is histologically indistinguishable from the bone Ewing sarcoma. The translocation involving chromosome 22 along with CD 99 expression is pathognomonic and is useful in differentiating from other small round cell tumours. Primary lung involvement by this malignant tumour is very uncommon and up to this date only ten cases have been reported. We report a further case in a 15 year-old-female who presented with a huge lung mass causing an opaque haemithorax.

A case report of neonatal orbital peripheral primitive neuroectodermal tumor and literature review.

Primitive neuroectodermal tumors are rare malignant neoplasms from primitive neural crest cells. Most primitive neuroectodermal tumors occur in the central and sympathetic nervous systems. We report a Chinese newborn patient presenting a huge unilateral proptosis after birth, diagnosed as orbital peripheral primitive neuroectodermal tumor by histopathology and immunohistochemistry. Our case is the first reported case of orbital peripheral primitive neuroectodermal tumor diagnosed in the newborn period. The clinical manifestations, radiological findings, histopathologic, and immunohistochemistry results are described in detail. We also conducted a literature search focusing on primitive neuroectodermal tumor of the orbit. To the best of our knowledge, all articles with English abstracts were reviewed here.

Features of a rare peripheral primitive neuroectodermal tumour arising from the thoracic spine in a juvenile canine patient.

Peripheral primitive neuroectodermal tumours are rare tumours in juveniles. The current patient was a paraplegic 8-month-old Scottish deerhound with a suspected pulmonary mass. Radiographically, there was a large extrapleural mass within the mid-left hemithorax. On MRI, the mass was mainly hyperintense on T2-weighted images, isointense on T1-weighted images and was heterogeneously strongly contrast enhancing with a multilobulated appearance, spinal cord compression, paraspinal musculature invasion and intrathoracic extension. Those changes were confirmed on post-mortem, and the mass diagnosed based on immunohistochemistry.

Comparative analysis of magnetic resonance imaging and pathological findings of microcystic meningioma and meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumors.

Microcystic meningiomas (MCMs) and meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs) are difficult to differentiate because of the similarity in their image manifestation on magnetic resonance imaging (MRI). Differential diagnosis of these two tumours before surgery could contribute to ameliorating clinical decision-making, and predicting prognosis. Here, we aimed to comparatively analyse the difference between MRI and pathological findings of these two tumours. Thirteen cases of MCM and eleven cases of meningeal Ewing sarcoma/pPNET confirmed through pathology were analysed retrospectively. The imaging features of the two tumours were statistically analysed using the Chi square test. The average age of patients with MCM and meningeal Ewing sarcoma/pPNET was 47 ± 18.4 years and 20 ± 13.2 years, respectively. Features of MRI, including tumour morphology, dural tail sign, bony destruction, and distant metastasis, were significantly different between the two tumours (p < 0.001). T1-weighted (T1W) signal and enhanced features resulted in a p value of < 0.05. There were no significant differences in the T2-weighted (T2W) signal and peri-tumoural oedema (p > 0.05). MCM immunohistochemistry showed that all the cases were positive for vimentin (Vim), epithelial membrane antigen (EMA), and the ki-67 index was less than 5%, while all the cases of meningeal Ewing sarcoma/pPNET were positive for Vim and CD99, and the ki-67 index was more than 30%. MRI imaging features of MCMs and meningeal Ewing sarcoma/pPNETs were different. Accurate preoperative diagnosis of these two tumours is helpful in implementing a clinical surgical plan and further management. Moreover, imaging combined with pathology can explain the imaging characteristics better.

Primary Peripheral Primitive Neuroectodermal Tumor of the Prostate on 18F-DCFPyL PET/CT.

Peripheral primitive neuroectodermal tumor (PNET) is a group of malignant tumors composed of small round cells. Peripheral PNET usually originates in the skeletal system. However, the presence of PNET lesion in prostate is extremely rare. We report a case of a 40-year-old man who presented with dysuria for more than 2 months. Pelvic MRI indicated prostatic malignant tumor, and F-DCFPyL PET/CT showed an isolated prostatic mass with high uptake of F-DCFPyL. Although F-DCFPyL is very specific for prostatic adenocarcinoma, a final diagnosis of peripheral PNET was made by pathology examination.