Peripheral Primitive Neuroectodermal Tumor Research Articles

Primary intracranial peripheral primitive neuroectodermal tumor: lessons from an exceptionally rare neoplasm. Illustrative case.

The primary intracranial peripheral primitive neuroectodermal tumor (pPNET) is a lesion subtype within the Ewing sarcoma family of tumors. pPNETs are extremely uncommon pathologies, accounting for 0.03% of intracranial tumors and 1% to 2% of Ewing sarcoma cases. Given its histological aspect similar to other highly proliferative malignant neuroectodermal neoplasms, pPNET merits extensive workup for accurate diagnosis and treatment. A 36-year-old male presented to the emergency department with a 1-year history of headaches in the right frontoparietal area, generalized tonic-clonic seizures, and a history of the resection of a tumor labeled as a meningioma 5 years before admission. He was neurologically intact. Brain magnetic resonance imaging revealed a heterogeneous focal lesion of 25 × 35 × 23 mm with a necrotic center and neoformative appearance in the right frontal cortex. The patient underwent multimodal treatment with gross-total resection, radiotherapy, and chemotherapy. Histopathological examination results supported the diagnosis of pPNET. At the 2-year follow-up, the patient had no new-onset symptoms, and brain imaging revealed absent signs of tumor recurrence. The present case describes an extraordinary pPNET case, initially confounded as a clear cell meningioma. Managing pPNET requires thorough investigation, careful differentiation from similar neuroectodermal lesions, and multimodal treatment to improve the patient's prognosis.

Ewing’s Sarcoma of the Adrenal Gland; A Rare Extraosseous Presentation

Ewing sarcoma also known as peripheral primitive neuroectodermal tumors (ES/PPNETs) usually produce in the chest wall, extraosseous soft tissues, and long or flat bones, however only rarely in solid organs. Although they can develop in any part of the body, development in the adrenal glands is very uncommon. We present a case of Ewing sarcoma (PNET) of the adrenal gland and the extraordinary diagnostic and therapeutic challenges faced during its diagnosis. Early detection of extraosseous disease with radiological imaging and the multimodality treatment strategy lowers morbidity and death in Ewing’s sarcoma of the adrenal gland.

Tumor neuroectodérmico primitivo na coluna cervical de um cão - Relato de Caso

ABSTRACT A case of peripheral primitive neuroectodermal tumor in the cervical region of a canine is described. The patient was a canine, male, five years old, large size, with acute neurological clinical signs, severe neck pain and tetraplegia. On computed tomography, an oval-shaped mass located dorsally to cervical vertebrae C4 to C7 was observed, with infiltration over the spinal cord between vertebrae C4 and C5, discreetly widening the dorsal intervertebral foramina of the cervical vertebrae and compressing the dorsal portion of the spinal cord of this segment. Under microscopy, the neoplastic cells were small, irregular in shape and with scarce cytoplasm. Immunoreactivity for vimentin, which can only be expressed in PTNEs tumors, was decisive for diagnostic confirmation. Additionally, the positivity of the S-100 protein, which is expressed in neuroectodermal cells mainly of the neural crest cells, reinforced the classification as PTNE, and the negativity in the expression for glial fibrillary acidic protein (GFAP) ruled out the presence of small cell glioma of the central nervous system. Based on the clinical history, imaging exams, cellular morphology and mainly on immunohistochemical staining, the diagnosis of primitive neuroectodermal tumor (PTNE) with infiltration and compression of the spinal cord in the cervical region of the dog was confirmed, considered uncommon in this species.

Detection of various fusion genes by one-step RT-PCR and the association with clinicopathological features in 242 cases of soft tissue tumor.

Introduction: Over the past decades, an increasing number of chromosomal translocations have been found in different STSs, which not only has value for clinical diagnosis but also suggests the pathogenesis of STS. Fusion genes can be detected by FISH, RT-PCR, and next-generation sequencing. One-step RT-PCR is a convenient method to detect fusion genes with higher sensitivity and lower cost. Method: In this study, 242 cases of soft tissue tumors were included, which were detected by one-step RT-PCR in multicenter with seven types of tumors: rhabdomyosarcoma (RMS), peripheral primitive neuroectodermal tumor (pPNET), synovial sarcoma (SS), myxoid liposarcomas (MLPS), alveolar soft part sarcoma (ASPS), dermatofibrosarcoma protuberans (DFSP), and soft tissue angiofibroma (AFST). 18 cases detected by one-step RT-PCR were further tested by FISH. One case with novel fusion gene detected by RNA-sequencing was further validated by one-step RT-PCR. Results: The total positive rate of fusion genes was 60% (133/213) in the 242 samples detected by one-step RT-PCR, in which 29 samples could not be evaluated because of poor RNA quality. The positive rate of PAX3-FOXO1 was 88.6% (31/35) in alveolar rhabdomyosarcoma, EWSR1-FLI1 was 63% (17/27) in pPNET, SYT-SSX was 95.4% in SS (62/65), ASPSCR1-TFE3 was 100% in ASPS (10/10), FUS-DDIT3 was 80% in MLPS (4/5), and COL1A1-PDGFB was 66.7% in DFSP (8/12). For clinicopathological parameters, fusion gene status was correlated with age and location in 213 cases. The PAX3-FOXO1 fusion gene status was correlated with lymph node metastasis and distant metastasis in RMS. Furthermore, RMS patients with positive PAX3-FOXO1 fusion gene had a significantly shorter overall survival time than those patients with the negative fusion gene. Among them, the FISH result of 18 cases was concordant with one-step RT-PCR. As detected as the most common fusion types of AHRR-NCOA2 in one case of AFST were detected as negative by one-step RT-PCR. RNA-sequencing was used to determine the fusion genes, and a novel fusion gene PTCH1-PLAG1 was found. Moreover, the fusion gene was confirmed by one-step RT-PCR. Conclusion: Our study indicates that one-step RT-PCR displays a reliable tool to detect fusion genes with the advantage of high accuracy and low cost. Moreover, it is a great tool to identify novel fusion genes. Overall, it provides useful information for molecular pathological diagnosis and improves the diagnosis rate of STSs.

Clinical and histopathological spectrum of cranial small round cell tumors: An experience from a tertiary care center.

Small round cell tumors (SRCTs) are a group of malignant neoplasms with minimal or no differentiation, characterized by the presence of round cells with high nuclear-cytoplasmic ratio. Although SRCTs can occur in any part of the body, involvement of central nervous system (CNS) is uncommon. We aimed to study the clinicopathological spectrum of cranial SRCT diagnosed in our institute over a period of four years (2016-2019). A retrospective review of medical records (2016-2019) with a morphological diagnosis of cranial SRCT was made. Both intra-axial and extra-axial tumors were included. A total of 60 cases were retrieved, and the clinical and histopathological features were studied. Special cytochemical staining and immunohistochemistry were performed, where needed. The mean age at presentation was 18.4 years (range, 1-60 years), with a male-to-female ratio of 2.5:1. The most common site was posterior fossa of brain (n = 28, 47%), followed by dorso-lumbar spine (n = 9, 15%). The most common type of tumor was medulloblastoma (n = 29, 48.3%), followed by Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumor (pPNET) (n = 11, 18.3%), non-Hodgkin lymphoma (NHL) (n = 9, 15%), neuroblastoma (n = 3, 5%), and CNS embryonal tumor, NOS (n = 2, 3.3%). One case each of atypical teratoid rhabdoid tumor (ATRT), rhabdomyosarcoma, pineoblastoma, melanoma, rhabdomyosarcoma, and undifferentiated pleomorphic sarcoma was also documented. SRCTs have a variable age of presentation. Their incidence in CNS is low as compared to other organ systems. On light microscopy, the histopathology of these lesions is overlapping, posing a great diagnostic dilemma for the pathologist. The use of ancillary techniques like immunohistochemistry helps in arriving at the correct diagnosis. Treatment strategy and tumor prognosis also vary along the entire spectrum of SRCT, thus making exact characterization essential for proper management.

Peripheral primitive neuroectodermal tumor orbit in an elderly woman.

Peripheral primitive neuroectodermal tumor orbit in an elderly woman.

Penile Ewing's Sarcoma - A Rare Entity

Abstract Introduction/Objective Ewing sarcoma is a cancer involving the bones or the tissue around bones. It is the second most common malignant bone tumour comprising 10-15% of all primary bone tumours, most commonly affecting children and young adults. It can also be seen in adults also. Males are more commonly affected then females. Any bone can be affected but the lower extremity, the pelvis, upper extremity, axial skeleton and ribs, and face cases. Similar histology tumours when seen in soft tissue are peripheral primitive neuroectodermal tumour (pPNET), neuroepithelioma, and Askin tumour. It is always difficult to know the primary site when soft tissues are involved as it can be infiltration from bone or from soft tissue to bone. Penis is least common site involved with Ewing’s sarcoma in young male. Methods/Case Report This is a case report of a 22 year old male with penile lesion. He presented with the chief complaints of mass at the shaft of penis. The partial penectomy specimen was received along with the bilateral inguinal lymph node. On gross there was a ulcero-proliferative growth. Results (if a Case Study Enter NA) On histopathological examination showed small blue round cell tumour and further immunohistochemistry with CD99 and NKX2.2 revealed the diagnosis of Ewing’s sarcoma, however lymph nodes showed reactive lymphoid hyperplasia. Conclusion The Ewing sarcoma at the penile region is rarest entity. Only 7 cases are reported worldwide. The imaging modalities like CT or MRI can be used to know the extension. The diagnosis is primarily based on morphological features, immunohistochemical analysis and translocation analysis. However it is important to find out if any other soft tissue site is involved. The important prognostic markers are presence and absence of metastasis, size of tumour, necrosis and presence of fusion transcripts.

Primary intracranial extraosseous Ewing's sarcoma of the skull base in an elderly adult: illustrative case.

BACKGROUNDPrimary extraosseous intracranial Ewing’s sarcoma, also known as a peripheral primitive neuroectodermal tumor or “small round blue cell tumor,” is an extremely rare entity with limited representation in the literature beyond the pediatric population.OBSERVATIONSA 67-year-old male suffering occipital headache, nausea, and gait disturbance was found to have a large, avidly contrast-enhancing cerebellopontine angle mass extending into the cervical spinal canal with associated mass effect on medulla, cerebellum, fourth ventricle, and cervical spinal cord. This mass was not present on the imaging from 8 years prior. He underwent surgical debulking and pathology results demonstrated a malignant small round cell tumor showing diffuse immunopositivity for cytokeratins, CD99 and NKX2.2 with EWRS1-FLI1 rearrangement in 84% of the nuclei confirmatory of Ewing’s sarcoma. After 14 cycles of chemotherapy and 6 weeks of radiotherapy, 22 months after discovery, the patient remains in clinical and radiographic remission with complete return to his baseline functioning.LESSONSPrimary skull base extraosseous Ewing’s sarcoma should be considered in the differential diagnosis even in the elderly population when imaging studies demonstrate aggressive tumor growth patterns. Tumor debulking to establish a diagnosis followed by adjuvant chemoradiation therapy can result in clinical improvement with remission.

Limping as the first manifestation of peripheral primitive neuroectodermal tumor (PNET) in children

Background: Ewing sarcoma (ES) and peripheral primitive neuroectodermal tumor (PNET) comprise the same spectrum of neoplastic diseases known as the Ewing sarcoma family of tumors (EFT). Ewing sarcoma is the most common bone sarcoma typically arising from bone and is one of the most common pediatric solid tumors. It mostly affects the bones of the lower parts of the body.

PRIMITIVE BLASTOMA PERIPHERAL PRIMITIVE NEUROECTODERMAL TUMOR OF THE MANDIBLE

Peripheral primitive neuroectodermal tumors (pPNET) are high-grade malignant tumors seen in the early age group {5-25 year}, primarily affecting long bones of extremities afterwards the pelvis, ribs and vertebrae. pPNET in the mandible (head & neck) accounts for only 2% of the reported cases. pPNET agitate difculty in arriving at a diagnosis due to poor differentiation of small round cells and could be established only by histopathology and immunochemistry. Surgery with chemotherapy is the preferrable treatment of choice in the mandible. In this article, we describe a rare case of PNET of the mandible in 11-year-old boy and review of literature.

Peripheral primitive neuroectodermal tumor: a case report

BackgroundPrimitive 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 presentationWe 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.ConclusionsEven 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.

Primary Ewing\u2019s sarcoma of the kidney: a rare masquerader of renal cell carcinoma on imaging

BackgroundThe Ewing sarcoma family of tumors comprises a group of high-grade small round cell tumors, including Ewing sarcoma of bone, extra-skeletal Ewing sarcoma, peripheral primitive neuro-ectodermal tumor (PNET), and Askin tumor (thoraco-pulmonary PNET). They are more prevalent in young children and adolescents. Ewing's Sarcoma is an aggressive tumor majorly described in bones. Primary renal Ewing's sarcoma is an extremely rare entity, characterized by a very aggressive course, with very few reported cases in the literature.Case presentationWe present an 18-year-old girl who presented with sudden onset left flank pain and hematuria. The patient had histopathology-proven primary renal Ewing's sarcoma, which was initially misdiagnosed as renal cell carcinoma on imaging.ConclusionsOwing to its non-specific radiological appearance, a high index of suspicion and a systematic approach is essential for detection of renal Ewing’s Sarcoma.

Ewing Sarcoma in the Sciatic Nerve: Case Report

AbstractEwing sarcoma (ES) is a malignant neoplasm that affects bones and soft tissues, usually in young patients. Currently, ES is grouped with other tumors that share the same histological and genotypic characteristics, forming the Ewing Sarcoma Family of Tumors (ESFT), which includes ES of bone, extraosseous ES (peripheral neuroepithelioma), Askin tumor, and peripheral primitive neuroectodermal tumor (PNET). Its origin in peripheral nerves is extremely rare, making its diagnosis and treatment very challenging. We describe a case of a 27-year-old male with extraosseous ES originating in the sciatic nerve, which was surgically removed, and discuss the difficulties encountered in the management of this patient.

Primary Ewing sarcoma/peripheral primitive neuroectodermal tumors in the cranial bone and mobile spine: what is the difference?

BackgroundPrimary Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumors (pPNETs) are aggressive bone tumors that rarely occur in the axial skeleton, including the cranial bone and mobile spine. The purpose of this study was to investigate whether there were any differences in patient characteristics, treatment strategies, and outcomes between patients with ES/pPNETs of the cranial bone and those with ES/pPNETs of the mobile spine.MethodsA retrospective study was performed on 33 patients with ES/pPNETs who had been surgically treated and pathologically confirmed at our institution between 2010 and 2020. Patient characteristics were compared using Fisher exact tests or independent t tests. Survival rates were estimated via Kaplan–Meier survival analysis and compared using log-rank tests.ResultsThirteen patients had ES/pPNETs of the cranial bone (39.4%), while 20 patients had ES/pPNETs of the mobile spine (60.6%). Patients with ES/pPNETs of the cranial bone had a younger mean age (14.8 vs 22.6 years; p = 0.047) and longer mean disease duration (2.5 vs 1.9 months; p = 0.008) compared with those of patients with ES/pPNETs of the mobile spine. Kaplan–Meier analysis showed that gross total resection (GTR) and radiotherapy resulted in a longer median survival time. The overall survival rates and progression-free survival rates of patients with ES/pPNETs of the cranial bone versus those of the mobile spine were not significantly different (p = 0.386 and p = 0.368, respectively).ConclusionsPatients with ES/pPNETs of the cranial bone were younger compared to patients with ES/pPNETs of the mobile spine. There was no significant difference in the prognosis of patients with ES/pPNETs of the cranial bone versus those of the mobile spine. Taken together, our findings suggest that GTR and radiotherapy offer the best prognosis for improved long-term survival.

Primary spinal peripheral primitive neuroectodermal tumour: a report of 3 cases and review of the literature

Peripheral primitive neuroectodermal tumours (PNETs) are rare and highly malignant tumours in the spine, with a predilection for young adults. There are no standard guidelines for treating these tumours. Surgical resection combined with postoperative radiotherapy and chemotherapy is a common and effective treatment at present. Even so, survival time of patients with these tumours is still very short. In this study, we present three rare cases of thoracic epidural PNETs and review the literature.

A RARE CASE OF EXTRASKELETAL EWING SARCOMA TUMOR DEVELOPING IN AN UNCOMMON LOCATION—FLOOR OF THE MOUTH

<h3>Introduction</h3> Ewing sarcomas (ESs) are uncommon malignant neoplasms that usually arise in long bones in young adults. They represent a family of high-grade tumors characterized by small round cells and include ES of bone and peripheral primitive neuroectodermal tumors. ES is poorly differentiated and may arise in bones or soft tissues; primitive neuroectodermal tumors tend to arise in soft tissues. Extraskeletal ES (EES) is very rare, particularly in the head and neck. Neoadjuvant chemotherapy improves survival; however, surgery remains an important treatment option. <h3>Case Description</h3> A 43-year-old Caucasian man presented with an otherwise asymptomatic slow-growing lump in the right submandibular/sublingual area. Magnetic resonance imaging confirmed the presence of a large mass above the mylohyoid, with suspicious characteristics. A fine-needle aspiration biopsy of the mass was suggestive of EES. The case was discussed in the head and neck and regional sarcoma MDTs. A larger sample was requested for further analysis, which confirmed the diagnosis. The patient started treatment with neoadjuvant chemotherapy and might require surgery at a later date. <h3>Discussion</h3> This case highlights the challenges faced when dealing with rare tumors. When is it reasonable to suspect malignancy in the absence of sinister symptoms? What technique offers appropriate diagnostic samples without compromising future resection? What tests allow prompt diagnosis? What management regime is indicated when specific data are lacking? We believe that such cases must be reported, to add to the knowledge of the scientific community, so that in the future optimal management can be offered in these challenging circumstances.

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

BackgroundThe 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 presentationA 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.ConclusionsThis 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.

A CASE OF PRIMITIVE NEUROECTODERMAL TUMOR (PNET) PRESENTING AS ANTERIOR MEDIASTINAL MASS

Peripheral primitive neuroectodermal tumors (pPNET) are a group of highly malignant tumors composed of small round cells of neuroetodermal origin that affect soft tissue and bone ,most commonly present in the thoracopulmonary region (Askin tumor), abdomen , pelvis and rarely in the head and neck. They usually present in the second decade of life, with slight male preponderance and account for 4-17% of all soft tissue tumors. Clinical symptoms depend on the site of presentation but invariably include pain and swelling of surrounding structure due to mass effect. Current recommendations advocate complete surgical resection whenever possible, adjuvant or neoadjuvant chemotherapy and radiotherapy. Here we present a 20 year old male patient who presented with chest pain and breathlessness and on investigation found to have an anterior mediastinal mass which further evaluation found to be a primitive neuroectodermal tumor

Cover Image

Cover caption: The cover image is based on the Case Report Features of a rare peripheral primitive neuroectodermal tumour arising from the thoracic spine in a juvenile canine patient by Adrien-Maxence Hespel et al., https://doi.org/10.1002/vms3.449.

Radiation Therapy (RT) Target Volume Definition for Peripheral Primitive Neuroectodermal Tumor (PPNET) by Use of Multimodality Imaging: An Original Article

Primitive neuroectodermal tumor (PNET) refers to a group of highly malignant tumors consisting of small round...