Operative treatment of pulmonary primitive neuroectodermal tumor: a case report and literature review.

BACKGROUND: Pulmonary primitive neuroectodermal tumor (PNET), a member of the Ewing sarcoma family of tumors, is a rare malignancy that is associated with a grim prognosis. To date, fewer than 30 cases of pulmonary PNET have been reported. In this case report, we present the clinical details of a 12-year-old girl with pulmonary PNET who underwent surgical treatment. We also conducted an analysis and summary of other relevant studies and the surgical outcomes. CASE PRESENTATION: In May 2018, a 12-year-old girl was admitted with symptoms of cough and blood-tinged phlegm. A computed tomography scan revealed a large mass, measuring 12.9 cm × 8.1 cm, in the right middle and lower lungs. A percutaneous lung biopsy confirmed poorly differentiated tumor cells with a nested growth pattern. Immunohistochemical staining demonstrated positive expression of CD99, CD56, Vimentin, and Synaptophysin. The patient was diagnosed with pulmonary PNET. Following three cycles of neoadjuvant chemotherapy, a substantial reduction in tumor volume was observed. Subsequently, the patient underwent a surgical procedure involving pneumonectomy and partial resection of the left atrium with the assistance of cardiopulmonary bypass. The patient was discharged 37 days after surgery. During a three-year follow-up period, she exhibited no signs of tumor recurrence and has successfully returned to school. CONCLUSIONS: This case highlights the successful management of an advanced PNET with neoadjuvant chemotherapy, pneumonectomy, and partial resection of the left atrium employing cardiopulmonary bypass. The patient remained disease-free after three years. Our analysis of surgically treated cases indicates that neoadjuvant chemotherapy can contribute to improved prognoses for PNET patients. It is crucial to emphasize that complete surgical excision remains the cornerstone of treatment, underscoring the importance of surgeons considering radical surgical approaches whenever feasible for patients with pulmonary PNETs.

Malignant gastrointestinal neuroectodermal tumor: a case report and literature review.

Introduction and importance: A malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare primary malignant mesenchymal tumor of the gastrointestinal tract characterized by EWSR1 gene rearrangement. An optimal systemic treatment strategy for advanced/recurrent GNET has not yet been identified. Case presentation: A 24-year-old male patient was hospitalized with abdominal pain and underwent two operations for a tumor in his small intestine. Immunohistochemistry (IHC) showed strong expression of S-100 protein and SOX 10. Fluorescence in situ hybridization analysis and next-generation sequencing analysis indicated that there were EWSR gene rearrangements and the presence of EWSR-ATP1 gene fusions, respectively. The diagnosis of GNET in the small intestine was confirmed by pathology. The young patient received the fifth-line of apatinib mesylate and the sixth-line of apatinib combined with temozolomide. The two apatinib-containing regimens showed stable disease and progression-free survival of 4.7 months and 3.1 months with single-agent apatinib or apatinib combined with temozolomide, respectively. Clinical discussion: To our best knowledge, this is the first report of malignant GNET treated with apatinib and temozolomide. Apatinib-containing regimens might has antineoplastic activity against GNET. The authors reviewed the relevant reports of previous GNET treatment, summarized the clinicopathological characteristics of GNET, and found that there are no reports of apatinib for backline treatment of GNET. Conclusion: Containing apatinib may provide an additional treatment option for patients with chemotherapy-resistant GNET tumors.

Clinical Significance of SOX10 Expression in Human Pathology.

The embryonic development of neural crest cells and subsequent tissue differentiation are intricately regulated by specific transcription factors. Among these, SOX10, a member of the SOX gene family, stands out. Located on chromosome 22q13, the SOX10 gene encodes a transcription factor crucial for the differentiation, migration, and maintenance of tissues derived from neural crest cells. It plays a pivotal role in developing various tissues, including the central and peripheral nervous systems, melanocytes, chondrocytes, and odontoblasts. Mutations in SOX10 have been associated with congenital disorders such as Waardenburg-Shah Syndrome, PCWH syndrome, and Kallman syndrome, underscoring its clinical significance. Furthermore, SOX10 is implicated in neural and neuroectodermal tumors, such as melanoma, malignant peripheral nerve sheath tumors (MPNSTs), and schwannomas, influencing processes like proliferation, migration, and differentiation. In mesenchymal tumors, SOX10 expression serves as a valuable marker for distinguishing between different tumor types. Additionally, SOX10 has been identified in various epithelial neoplasms, including breast, ovarian, salivary gland, nasopharyngeal, and bladder cancers, presenting itself as a potential diagnostic and prognostic marker. However, despite these associations, further research is imperative to elucidate its precise role in these malignancies.

Pineoblastoma en el adulto. A propósito de un caso

Fundamento: Los pineoblastomas son tumores cerebrales infrecuentes dentro del grupo de los tumores primitivos neuroectodérmicos. La presentación clínica por lo general está relacionada con la obstrucción del acueducto de Silvio, lo que ocasiona hidrocefalia e hipertensión intracraneal. Objetivo: Describir las características clínicas e imagenológicas de un paciente adulto con diagnóstico de pineoblastoma. Presentación de caso: Masculino, 33 años, que comenzó con disminución de la agudeza visual que evolucionó a la amaurosis bilateral y trastorno de la marcha. Se diagnosticó hidrocefalia obstructiva triventricular, por lo cual se realizó tercer ventriculostomía endoscópica. Se decidió un abordaje supracerebeloso infratentorial a la lesión tumoral, con apoyo endoscópico en posición semisentado; se logró la resección parcial. En estudio inmunohistoquímico se encontró Ki-67 mayor de 50 % de las células, neurofilamento y sinaptofisina positiva. Se concluyó como pineoblastoma. Recibió radioterapia convencional con Co-60, fraccionada, con un total de 30 dosis diarias de 2 Gy. La evolución del paciente a los 6 meses de operado fue satisfactoria. Conclusiones: El tratamiento combinado de cirugía y radioterapia constituye un esquema terapéutico ideal en este tipo de lesiones tumorales. La endoscopia es una herramienta de gran valor en los abordajes quirúrgicos a la región pineal.

Background: Pineoblastomas are infrequent brain tumors among the neuroectodermal primitive tumors. Clinical presentation is usually related to Silvian aqueduct obstruction, which causes hydrocephalus and intracranial hypertension. Objective: To describe the clinical and imagenological characteristics in an adult patient diagnosed with pineoblastoma. Case presentation: Male, 33 years old, who started with visual acuity decline that evolved to bilateral amaurosis and gait disorder. Triventricular obstructive hydrocephalus was diagnosed, therefore, an endoscopic third ventriculostomy was realized. It was decided to use an infratentorial supracerebellar approach to the tumor lesion, with endoscopic support in semi-seated position; partial resection was achieved. In immunohistochemical study, Ki-67 was found to be higher than 50% of the cells, neurofilament and synaptophysin positive. It was concluded as pineoblastoma. He received fractionated Co-60 conventional radiotherapy, with a total of 30 daily doses, 2 Gy. The evolution of the patient 6 months after surgery was satisfactory. Conclusions: The combined treatment of surgery and radiotherapy constitutes an ideal therapeutic scheme in this type of tumor lesions. Endoscopy is a tool of great value in surgical approaches to the pineal region.

Embryonal tumor with multilayered rosettes arising from the internal auditory canal of an adult: Illustrative case with molecular investigations.

Embryonal tumors with multilayered rosettes (ETMRs) are aggressive central nervous system (CNS) tumors that usually occur in young children. Here, we describe the first incidence of ETMR in an adult patient that also originated in the novel location of the internal auditory canal (IAC). The 36-year-old patient initially presented with unsteadiness, diplopia, and tinnitus. The tumor in the IAC was discovered on brain magnetic resonance imaging, and gross total resection was performed followed by pathological and molecular diagnosis. The patient received whole brain and spinal cord radiotherapy after an intracranial recurrence and adjuvant chemotherapy consisting of four cycles of ifosfamide, cisplatin, and etoposide. Progression was rapid; however, the patient survived for 22 months after diagnosis before succumbing to the disease. Molecular investigation revealed a DICER1 mutation at exon 25, and methylation classification categorized the tumor as ETMR, non-C19MC-altered. This case underscores the diverse possible presentations of ETMR, DICER1-mutated and the importance of molecular techniques to characterize and promptly treat atypical ETMR.

[Peripheral neuroblastic tumors in childhood]. / Periphere neuroblastische Tumoren im Kindesalter.

Peripheral neuroblastic tumors represent the fourth-largest group of malignant tumors in childhood. The majority of these tumors are neuroblastomas, which can be classified into undifferentiated, poorly differentiated, and differentiating subtypes. In addition, peripheral neuroblastic tumors include ganglioneuroblastoma, a composite tumor composed of Schwannian cell stroma and neuroblasts as well as benign ganglioneuroma. In this overview, histopathological diagnostic criteria and grading systems, as well as common molecular alterations that are of prognostic and therapeutic significance, are discussed.

Schwannoma intraóseo en fémur, una presentación inusual. Reporte de caso / Intraosseous Schwannoma in femur, an unusual presentation. Case report

El Schwannoma o Neurilemoma es un tumor benigno de derivación neuroectodérmica que se origina en las células de Schwann, que constituyen la envoltura de los nervios. Es el tumor benigno más común de los nervios periféricos, tiene predisposición a originarse a partir de nervios periféricos sensoriales y puede presentarse como tumores en tejidos blandos. La presentación intraósea del Schwannoma es rara y corresponde al 0,2% de los tumores óseos primarios. Se presenta caso clínico de paciente masculino de 36 años de edad con tumor en cóndilo femoral medial de rodilla derecha de 4 años de evolución, cursando con dolor intermitente moderado a quien se le practicó el protocolo oncológico, imagenológico e histológico, de la Unidad de Oncología Ortopédica del estado Monagas. Se diagnosticó Schwannoma intraóseo, se procedió a realizar resección marginal y reconstrucción con alloinjerto y fijación con placa y tornillos con excelente evolución postoperatoria. El Schwannoma intraóseo es extraordinariamente raro y su ubicación en el fémur lo es aún más. El objetivo del presente trabajo es reportar un caso de Schwannoma Intraóseo, mostrar las estrategias para su diagnóstico y los tratamientos aplicados, así como la revisión de los datos al respecto existentes en la literatura(AU)

Schwannoma or Neurilemoma is a benign tumor of neuroectodermal derivation that originates in Schwann cells, which constitute the nerve sheath. It is the most common benign tumor of the peripheral nerves, has a predisposition to originate from peripheral sensory nerves, and can present as soft tissue tumors. The intraosseous presentation of Schwannoma is rare and corresponds to 0,2% of primary bone tumors. A clinical case of a 36-yearold male patient with a tumor in the medial femoral condyle of the right knee of 4 years of evolution is presented, presenting with moderate intermittent pain who underwent the oncological, imaging and histological protocol of the Oncology Unit. Monagas State Orthopedic. Intraosseous Schwannoma was diagnosed, marginal resection and allograft reconstruction and plate and screw fixation were performed with excellent postoperative evolution. Intraosseous Schwannoma is extraordinarily rare and its location in the femur is even more so. The objective of this paper is to report a case of Intraosseous Schwannoma, show the strategies for its diagnosis and the treatments applied, as well as the review of the existing data in the literature(AU)

Sarcoma de Ewing multifocal: presentación de un caso pediátrico / Multifocal Ewing sarcoma: presentation of a pediatric case / Sarcoma de Ewing Multifocal: apresentação de um caso pediátrico

Introducción: el Sarcoma de Ewing es una neoplasia maligna de origen mesenquimático. Al momento del diagnóstico el 75% se presentan en forma localizada. Objetivo: comunicar un caso que por su presentación multifocal, generó dificultades diagnósticas. Caso clínico: niña de 6 años. Consulta por traumatismo de mano derecha tras caída de su altura 24 horas previas, constatándose en mano y puño derecho edema, calor y eritema, movilidad conservada. No fiebre. Radiografía: aumento del diámetro del tercer metacarpiano, imagen esmerilada, no trazos de fracturas. Ingresa con planteo de celulitis. Anemia leve microcítica, hipocrómica. Proteína C reactiva 82 mg/l. Recibe clindamicina intravenosa 72 horas, completa 14 días vía oral. Persistencia de alteraciones en puño y mano derecha, agrega tumoración de raíz nasal con desviación del eje, indolora. Fosfatasa alcalina, lactato deshidrogenasa, fosfatemia, calcemia normales. Resonancia magnética: alteración morfoestructural de radio, olecranon y tercer metacarpiano, fractura de olecranon y radio, reacción perióstica. Pet-Scan: lesión extensa ósea en macizo facial, tibias, cúbitos, humero derecho y clavícula. Biopsia 3er metacarpiano: tumor de células pequeñas, redondas azules, CD99 y vimentina positivo. Comienza poliquimioterapia y radioterapia sin complicaciones. Conclusiones: es frecuente que las manifestaciones clínicas iniciales sean confundidas con entidades más frecuentes, como post-traumáticas y/o inflamatorias, tal como ocurrió en este caso. Posteriormente, la aparición de nuevas lesiones y compromiso del estado general orientó el abordaje diagnóstico de la patología tumoral. La confirmación exige el estudio anatomopatológico con estudio inmunohistoquímico. La presencia de metástasis óseas constituye un factor de mal pronóstico y dificulta el abordaje terapéutico.

Introduction: Ewing's sarcoma is a malignant neoplasm of mesenchymal origin. At the time of diagnosis 75% of the cases are localized. Objective: to report a case that, due to its multifocal presentation, generated diagnostic difficulties. Clinical case: 6-year-old girl. She consulted for right hand trauma after a fall from her height 24 hours earlier, with edema, warmth and erythema in the right hand and fist, with preserved mobility. No fever. X-ray: increase in the diameter of the 3rd metacarpal, frosted image, no traces of fractures. Admitted with cellulitis. Mild microcytic anemia, hypochromic. C-reactive protein 82mg/l. Receives intravenous clindamycin 72 hours, completes 14 days orally. Persistence of alterations in fist and right hand, adds tumor of nasal root with deviation of the axis, painless. Alkaline phosphatase, lactate dehydrogenase, phosphatemia, normal calcemia. MRI: morphostructural alteration of radius, olecranon and 3rd metacarpal, fracture of olecranon and radius, periosteal reaction. Pet-Scan: extensive bone lesion in facial mass, tibiae, ulnae, right humerus and clavicle. Biopsy 3rd metacarpal: small cell tumor, blue round, CD 99 and vimentin positive. Polychemotherapy and radiotherapy were started without complications. Conclusions: it is frequent that the initial clinical manifestations are confused with more frequent entities, such as post-traumatic and/or inflammatory, as occurred in this case. Subsequently, the appearance of new lesions and compromise of the general condition guided the diagnostic approach of the tumor pathology. Confirmation requires anatomopathological study with immunohistochemical study. The presence of bone metastases constitutes a poor prognostic factor and hinders the therapeutic approach.

Introdução: O sarcoma de Ewing é um neoplasma maligno de origem mesenquimatosa. No momento do diagnóstico, 75% dos casos são localizados. Objetivo: Relatar um caso que, devido a sua apresentação multifocal, causou dificuldades diagnósticas. Caso clínico: Menina de 6 anos. Ela consultou por traumatismo à mão direita após cair de sua altura 24 horas antes, com edema, calor e eritema na mão direita e punho, com mobilidade preservada. Sem febre. Raio-X: aumento do diâmetro do 3º metacarpo, imagem fosca, sem vestígios de fraturas. Admitido com a sugestão de celulite. Anemia microcítica leve, hipocrómica. Proteína C reativa 82mg/l. Recebe clindamicina intravenosa por 72 horas, completa 14 dias por via oral. Persistência de alterações no punho e mão direita, tumor indolor da raiz nasal com desvio do eixo. Fosfatase alcalina, desidrogenase láctica, fosfataemia, calcemia normal. IRM: alteração morfo-estrutural do rádio, olecrânio e 3º metacarpo, fratura do olecrânio e do rádio, reação periosteal. Pet-Scan: extensa lesão óssea na massa facial, tíbia, ulnae, úmero direito e clavícula. Biópsia do 3º metacarpo: tumor de pequenas células, redondo azul, CD 99 e vimentina positiva. Ela iniciou a poli-quimioterapia e radioterapia sem complicações. Conclusões: É comum que as manifestações clínicas iniciais sejam confundidas com entidades mais freqüentes, tais como pós-traumáticas e/ou inflamatórias, como ocorreu neste caso. Posteriormente, o aparecimento de novas lesões e o envolvimento do quadro geral levaram a uma abordagem diagnóstica da patologia tumoral. A confirmação requer um estudo anatomopatológico com estudo imuno-histoquímico. A presença de metástases ósseas é um fator de mau prognóstico e dificulta a abordagem terapêutica.

The Malignant Gastrointestinal Neuroectodermal Tumor (GNET): A Distinct Entity and the Challenging Differential Diagnosis with Mesenchymal, Lymphoid, and Melanic Tumors: A Case Report and Brief Review of the Literature.

(1) Background: A malignant gastrointestinal neuroectodermal tumor (GNET) is an ultra-rare primary neoplasm with a distinctive histopathological, immunohistochemical, molecular, and ultramicroscopic profile, synonymous terminology with clear cell sarcoma-like tumor of the gastrointestinal tract. This case report aims to describe a case of GNET with challenging mesenchymal, lymphoid, and melanic tumor differential diagnosis. (2) Case presentation: We discuss the case of a 67-year-old male patient who presented with diffuse abdominal pain, intermittent lack of intestinal transit, and frequent episodes of nausea, followed by segmental resection of the jejunum and sigmoid colon. The patient had no relevant medical history. The surgical specimen underwent immunohistochemical staining and morphological evaluation. (3) Results: Histopathological analysis reveals a moderately homogeneous polyhedral-epithelioid and spindle cell neoplastic proliferation with a zonal discohesive pattern and extensive and focal fasciculated architecture. Twenty monoclonal antibodies were used for immunostaining, which allowed GNET to be diagnosed on the basis of the tumoral immune profile, characterized by positive reactivity of S100, SOX10, and CD 56. (4) Conclusions: The poor prognosis of GNET is highlighted in the present study, along with the vital importance of differential diagnosis issues with mesenchymal, lymphoid, and melanic tumors, which make the diagnosis difficult for both pathologists and clinicians.

A rare case of a peripheral Ewing sarcoma primitive neuroectodermal tumor of pelvic origin.

Primitive neuroectodermal tumors (PNET) represent malignant neuroectodermal tumors composed of small round cells. They can be differentiated between originating from the peripheral nervous system or the central nervous system. Peripheral PNET (pPNET) can be further subclassified as one of the Ewing family tumors (EFT). Although rare, EFT can originate in the female genital tract and pelvic region. Here, we present a case of a middle-aged female with PNET masses in her uterus, abdomen, and hepatic lobes. We discuss the diagnostic modalities, including immunohistochemistry, histopathology, and imaging findings associated with this rare malignancy.

Hypercalcemic Crisis: A Rare Presentation of Ewing's Sarcoma.

Ewing's sarcoma (ES) is a rare malignancy of adolescence that usually presents with clinically apparent disease involving long bones, brought to attention by trauma and/or fractures. Hypercalcemia of malignancy is a well-known phenomenon; however, hypercalcemia is exceptionally rare in ES. This case report discusses a 20-year-old lady who experienced chronic bone pains in her hip and lower limbs, ultimately leading to a hypercalcemic crisis. We emphasize the importance of considering ES as a potential cause of hypercalcemia, highlighting the mechanism, diagnostic and therapeutic challenges, the associated poor prognosis, and the necessity for a multidisciplinary approach to managing the condition.

Sarcoma de Ewing extraesquelético: relato de um caso raro e exuberante simulando lipoma / Extraskeletal Ewing's sarcoma: report of a rare and exuberant case simulating lipoma

Sarcoma de Ewing extraesquelético (EES) é tumor raro e agressivo, acomete mais homens entre 10-20 anos e representa 25% dos sarcomas de Ewing. Caso relatado pelo diagnóstico prévio de lipoma de crescimento acelerado, destacando a importância do diagnóstico histopatológico. Masculino, 14 anos, apresentando tumoração de 10x10cm no ombro direito há um ano, com ultrassonografia sugestiva de lipoma. Realizada exérese da lesão, sendo confirmado EES pela imuno-histoquímica. O diagnóstico de EES em jovens é desafiador frente a outras tumorações subcutâneas, sendo a histopatologia imprescindível. A rápida progressão do tumor e os elevados índices metastáticos evidenciam a importância da terapêutica precoce.

Extraskeletal Ewing sarcoma (EES) is a rare tumor that affects men between 10-20 years old and represents 25% of Ewing sarcomas. We report a case due to the previous diagnosis of a fast-growing lipoma to highlight the importance of histopathological diagnosis. A 14-year-old boy presented 10x10 cm tumor in the right shoulder for a year with ultrasonography suggesting lipoma. The lesion was excised and EES was confirmed by immunohistochemical analysis. EES diagnosis in young people is challenging compared to subcutaneous tumors, and histopathology is essential. The rapid progression of the tumor and high metastatic rates highlight the significance of early treatment.

Case report: Primary intracranial EWs/PNET in adults: Clinical experience and literature review.

Introduction: Adult primary intracranial Ewing sarcomas (EWs)/primitive neuroectodermal tumors (PNETs) are extremely rare, with only 30 patients published before us. The imaging features and treatment strategies of primary intracranial EWs/PNETs are unclear due to its rarity. The aim of this study was to investigate the clinical features, imaging findings, treatment, survival analysis, and prognosis of adult EWs/PNETs, and a systematic review was conducted based on the patient we treated and published literature. Case description: A 19-year-old male patient suffered from head pain due to an accidental fall on a motorcycle that occurred more than 10 days before going to the hospital, and underwent computed tomography (CT) examination; it was found that the left temporo-occipital fossa was occupied. Magnetic resonance imaging (MRI) was recommended to understand the nature of the lesion, and the result showed that it has a high probability of being a meningioma. He underwent surgical removal of the mass under general anesthesia, and surprisingly, postoperative pathology revealed EWs/PNET. The disease has a high degree of malignancy, and the patient developed multiple metastases throughout the body 5 years after surgery. Conclusion: Primary intracranial EWs/PNETs in adult patients are rare, of which imaging findings should be considered as one of the differential diagnoses of meningioma, hemangiopericytoma, and malignant triton tumor. Larger solid-cystic masses with septum-like enhancement may be relatively specific imaging findings of intracranial EWs/PNETs. The prognosis of primary adult intracranial EWs/PNETs is poor. Radical tumor resection combined with radiotherapy and chemotherapy is currently the main and possibly the most effective treatment method.

Dural-Based Posterior Fossa Medulloblastoma Mimicking a Petrous Meningioma in Late Adulthood.

Background: Medulloblastoma of the posterior fossa is commonly encountered in pediatric populations but rarely reported in adults. Adult cases of medulloblastoma typically occur in younger patients, tend to arise intra-axially within the cerebellar hemisphere, and usually exhibit classic histopathologic features. Case Report: A 54-year-old male presented with headaches, dizziness, gait instability, and frequent falls that had worsened during the prior 3 months. Imaging and histopathologic analysis revealed extra-axial, dural-based posterior fossa medulloblastoma with desmoplastic/nodular histopathology, mimicking a petrous meningioma. The mass occupied the left cerebellopontine angle. The patient underwent microsurgical gross total resection of the tumor followed by proton beam radiation therapy and was disease-free at 1-year follow-up. Conclusion: Few dural-based posterior fossa medulloblastomas resembling petrous meningiomas have been reported, and to our knowledge, this is the first description of a case to be treated successfully with proton beam therapy in an older adult. Although rare, medulloblastoma can occur extra-axially in the cerebellopontine angle of older adults, potentially mimicking a petrous meningioma. This rare possibility should always be kept in mind, especially if expectant, nonsurgical management is being considered. To optimize outcome, posterior fossa medulloblastoma should be treated with aggressive microsurgical resection followed by radiation therapy. When available, proton beam therapy should be considered.

Embryonal tumor with multilayered rosettes in a teenager.

BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR), NOS/C19MC- altered, is a rare and recently classified highly aggressive malignant brain tumor in the 2021 World Health Organization (WHO) classification of tumors of the central nervous system 5th edition. They are mostly diagnosed in children before the age of three years. Most of them are located in the supratentorial region. Prior to the reclassification of ETMR as a single entity, three distinct tumors, namely, embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL) and medulloepithelioma (MEPL) were recognized. Recent studies showed that all the three entities have multilayered rosettes on morphology, sharing a common amplification of the C19MC locus at the chromosome 19q13.42 by fluorescence in situ hybridization, and highly specific immunohistochemical staining for LIN28A rendered their reclassification as a single entity. REPORT: A 13-year-old girl was rushed to the emergency room unconscious, with no return of spontaneous circulation after cardiopulmonary resuscitation. Autopsy revealed a left cerebellar hemisphere hemorrhagic tumor which histopathological examination revealed a multilayered ependymoblastic rosettes with abundant neuropil. The multilayered rosettes showed reactivity for vimentin but non-reactivity for pan-cytokeratin, the zones with abundant neuropil were reactive for synaptophysin consistent with a diagnosis of embryonal tumor with abundant neuropil and true rosettes now ETMR, NOS (WHO Grade 4) due to the lack of genetic testing for amplification of C19MC. CONCLUSION: ETMR is a highly aggressive CNS embryonal tumor with extremely poor prognosis. It should be considered in the differential diagnosis of pediatric brain tumors. Multilayered rosettes are a useful clue to histologic diagnosis.

Ewing Sarcoma/Primitive Neuroectodermal Tumor Involving the Duodenum.

Background: Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is a soft tissue malignancy arising from the neuroectoderm. While the locations of these extraskeletal manifestations are diverse, origin from the small bowel and small bowel mesentery is extremely rare. Intra-abdominal manifestations of ES/PNETs are nonspecific, and patients present with a wide range of symptoms, most frequently vague abdominal pain. Case Report: A 66-year-old female initially presented with vague and nonspecific symptoms of hypotension, anemia, dyspnea, and coffee-ground emesis. Imaging workup with computed tomography and fluorodeoxyglucose positron emission tomography demonstrated a metabolically active large mass involving the duodenum and measuring 10.3 × 8.8 × 12.3 cm. The mass was characterized as an ES/PNET on histopathologic diagnosis. The patient was treated with chemotherapy followed by radical resection and was disease-free at 1 year postpresentation. Conclusion: This case highlights that while ES/PNETs are rare tumors of the abdomen, they should be considered in cases of large soft tissue masses in patients presenting with nonspecific symptoms. To the best of our knowledge, this case is the fourth report in the literature of an ES/PNET involving the duodenum.

Primary Adult Renal Ewing's Sarcoma: A Rare Entity.

Ewing's sarcoma/primitive neuroectodermal tumors are high-grade small round blue cell tumors traditionally found in children and adolescents.These tumors primarily affect the bone and soft tissue, with extraskeletal sites rarely being affected. The clinical presentation and imaging findings are non-specific and are not characteristic. The diagnosis is essentially based on the histopathologic findings assisted by immunohistochemistry and/or cytogenetic molecular studies. Proper diagnoses and timely management of this tumor are essential owing to the aggressive nature and poor prognosis of the disease.

Primary intracranial peripheral primitive neuroectodermal tumor in an adult patient with aphasia: A rare case report.

Primary intracranial peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare malignancies that commonly affect children and adolescents. Only 10 cases over the age of 33 have been reported. pPNETs have an aggressive behavior and a high tendency for local recurrence and distant metastasis. Here, we present a case of supratentorial pPNET that affected the left frontoparietal lobe of a 36-year-old female patient. The patient complained of aphasia during the last 2 months. Aphasia is reported for the first time as a result of a pPNET. In T1-weighted MRI, a large mass with mixed isointense to hypointense signals was observed. The tumor was completely removed. Histopathologic examination was indicative of a small round cell tumor. Immunohistochemical analysis showed positivity for CD99. Presence of EWSR1 gene rearrangement confirmed the diagnosis. The patient's aphasia was gradually resolved post-surgery. Six months follow-up showed no evidence of local recurrence or metastasis.