Tumor neuroectodérmico maligno del tracto gastrointestinal: a propósito de un caso / Malignant neuroectodermal tumor of the gastrointestinal tract: case report

El tumor neuroectodérmico maligno del tracto gastrointestinal es una neoplasia rara con pocos casos reportados en la literatura, especialmente en América Latina. Descrito por primera vez en 2003, se trata de una entidad sin tratamiento estandarizado y de pobre pronóstico. Se presenta el caso de una paciente de 22 años de edad que acude a la consulta por dolor abdominal, anemia y masa abdominal palpable. Luego de estudios pertinentes se decide la conducta resectiva y el posterior tratamiento oncológico. (AU)

Malignant gastrointestinal neuroectodermal tumor (GNET), formerly known as clear cell sarcoma of the gastrointestinal tract, is an extremely rare tumor of mesenchymal origin, which presents great microscopic and molecular similarity to clear cell sarcoma found in other parts of the body, such as tendons and aponeurosis. It is characterized by its rapid evolution, high recurrence rate and frequent diagnosis as metastatic disease.1,2 (AU)

Schwannoma intraóseo mandibular: reporte de un caso clínico / Mandibular intraosseous schwannoma: a clinical case report

Objetivo: El schwannoma es un tumor neuroectodérmi- co benigno de la vaina nerviosa o vaina de mielina formada por células de Schwann. Aproximadamente entre el 25 y el 48% de los casos presentan localización en el territorio cer- vicofacial, especialmente en los tejidos blandos de esta re- gión. Se los puede clasificar como schwannomas periféricos o intraóseos, éstos últimos también denominados centrales. Los schwannomas intraóseos son poco comunes, constituyen menos del 1% de los schwannomas presentes en la región en cuestión y menos del 0,2% de todos los tumores primarios óseos. El presente trabajo tiene como objetivo reportar un caso clínico de un schwannoma intraóseo mandibular, revi- sando aspectos clínicos, radiográficos y anatomopatológicos. El schwannoma intraóseo es una entidad poco común, o al menos se encuentra en una condición de subregistro en Argen- tina, por lo que este caso constituye una rareza. Caso clínico: Se presentó a la consulta una paciente de 30 años de edad, derivada al servicio de Cirugía y Trau- matología Bucomaxilofacial del Hospital "Parmenio Piñero" de la Ciudad Autónoma de Buenos Aires por su odontólogo de cabecera, a raíz de un hallazgo radiográfico durante un control de rutina. Se planificó realizar una biopsia incisio- nal, cuyo resultado anatomopatológico fue compatible con el diagnóstico de schwannoma intraóseo. Se procedió a realizar la enucleación completa. Finalmente, la paciente evolucionó sin complicaciones (AU)

Aim: Schwannoma is a benign neuroectodermal tumor of the nerve sheath or myelin sheath formed by Schwann cells. Approximately between 25 and 48% of the cases are located in the cervicofacial territory, especially in the soft tissues of this region. They can be classified into peripheral and intraosseous schwannomas, the last one can also be reported as central. In- traosseous schwannomas are rare, constituting less than 1% of schwannomas present in the region and less than 0.2% of all primary bone tumors. This publication aims to report a clin- ical case of mandibular intraosseous schwannoma, reviewing clinical, radiographic and anatomopathological aspects. In- traosseous schwannoma is a rare entity, or at least is under a condition of underreport in Argentina, so this case is a rarity. Clinical case: A 30-year-old patient, referred to the Buccomaxillofacial Surgery and Traumatology service of the "Parmenio Piñero" Hospital of Ciudad Autónoma de Bue- nos Aires by her dentist, because of a radiographic finding during a routine check. An incisional biopsy was performed, the anatomopathological result of which was compatible with the diagnosis of intraosseous schwannoma. A complete enu- cleation was performed under local anesthesia. Finally, the patient evolved without complications (AU)

Tumor tritón maligno en región mandibular y cervical / Malignant triton tumor in the mandibular and cervical region

Introducción: El tumor tritón maligno es una neoplasia rara en la que se encuentran células rabdomioblásticas en un tumor maligno de la vaina de nervios periféricos, que se caracteriza por su agresividad y mal pronóstico. La localización en la cabeza y el cuello es poco frecuente. La inmunohistoquímica juega un papel importante en el diagnóstico. Objetivo: Describir un tumor tritón maligno de tamaño inusual. Presentación del caso: Paciente femenino, de 16 años, es referida al servicio de cirugía maxilofacial del Instituto Nacional de Pediatría, Ciudad de México, con un diagnóstico de tumor neuroectodérmico en región facial y cervical de un año de evolución. Clínicamente el tumor era exofítico, multilobulado, con zonas extensas de necrosis, superficie de varias tonalidades y un tamaño aproximado de 18 x 10 x 12 cm. Se realizó una biopsia e inmunohistoquímica que confirmó el diagnóstico de tumor tritón maligno. La paciente fue intervenida quirúrgicamente, procedimiento con el cual se eliminó totalmente la lesión, con márgenes de seguridad. La paciente presentó una evolución tórpida, con desenlace fatal al cabo de seis meses del tratamiento. Conclusiones: El tumor tritón es una neoplasia agresiva y su detección oportuna orienta al cirujano a ofrecer al paciente un tratamiento adecuado(AU)

Introduction: Malignant triton tumor is a rare neoplasm in which rhabdomyoblasts are present in a malignant tumor of the peripheral nerve sheath. This condition is characterized by its aggressiveness and bad prognosis. Location in the head and neck is infrequent. Immunohistochemical testing plays an important role in its diagnosis. Objective: Describe an unusually large malignant triton tumor. Case presentation: A case is presented of a female 16-year-old patient referred to the maxillofacial surgery service of the National Institute of Pediatrics in Mexico City with a diagnosis of neuroectodermal tumor of one year's evolution in the facial and cervical region. In clinical terms, the tumor was exophytic, multilobed, with extensive areas of necrosis, a surface in several shades of color and an approximate size of 18 x 10 x 12 cm. Biopsy and immunohistochemical testing confirmed the diagnosis of malignant triton tumor. The patient underwent surgery in which the lesion was totally excised with a safety margin. Evolution was clumsy, with a fatal outcome at six months of treatment. Conclusions: Triton tumor is an aggressive neoplasm whose early detection makes it possible for surgeons to provide an appropriate treatment(AU)

Primary Ewing sarcoma/primitive neuroectodermal tumor of the lung

We present the autopsy findings and differential diagnosis in a 42year old male who presented with fever and rapidly progressive respiratory symptoms like breathlessness, nonproductive cough and right sided chest pain. Initial imaging workup done at our hospital revealed a large unilateral tumor with tracheal shift. While being evaluated patient developed facial puffiness, tachypnea suggestive of superior vena cava obstruction. Antemortem biopsy of lung mass was attempted twice and that suggested malignant lesion. Unfortunately, the individual had a rapid downhill course following admission. Post mortem examination was conducted that on opening the thoracic cavity revealed total replacement of right lung tissue by a necrotic growth which was deeply adherent to the rib cage. The contralateral lung as well as all other visceral organs were unremarkable grossly. Histopathology confirmed primary Ewing sarcoma of the lung. We hereby, report a rare case of primary lung Ewing sarcoma diagnosed at autopsy.

Sarcoma de Ewing extraóseo en la columna dorsal con compresión medular al momento del diagnóstico: Reporte de un caso / Primary extra-osseous Ewing sarcoma of the dorsal spine with spinal cord compression at diagnosis: Case report

Los tumores neuroectodérmicos primitivos a nivel extraóseo son una neoplasia muy rara, con pocas publicaciones en la literatura. Se reporta un caso de una paciente de nueve años quien se presentó con signos de compresión medular. Se estableció un grupo de diagnósticos diferenciales en el abordaje, entre los que debió incluirse la patología oncológica. En la paciente, se observó la presencia de una masa en la columna dorsal con compromiso del cordón medular, que requirió cirugía descompresiva de urgencia y, posteriormente, se diagnosticó sarcoma de Ewing. Cabe resaltar la importancia del caso debido a la baja incidencia del origen extraóseo en esta neoplasia y su rara localización en la columna dorsal, y destacar la presencia de la compresión medular como forma de presentación del cáncer en pediatría, además de la poca información que, hasta el momento, se posee referida al mejor abordaje terapéutico en esta patología, en esta localización.

Extraosseous primitive neuroectodermal tumors are very rare neoplasms. Only a few cases have been published in the literature. This report is about a 9-year-old female patient whose clinical manifestations showed spinal cord compression, so different diagnosis should be considered, including oncology disease. The patient showed a mass of the dorsal spine with spinal cord compression. She was diagnosed with Ewing Sarcoma after surgical intervention and pathology study. It is necessary to highlight the importance of the present case due to the low incidence of the extraosseous Ewing Sarcoma, and its infrequent location at the dorsal spine and the spinal cord compression as initial presentation of pediatric cancer, as well as the poor information related to the best therapeutic strategy to treat this disease at this location.

Successful Surgical Treatment of a Recurrent Esophageal Malignant Gastrointestinal Neuroectodermal Tumor

Malignant gastrointestinal neuroectodermal tumor (GNET) is a very rare disease entity, especially in the esophagus. The diagnosis of GNET is based on histologic, immunohistochemical, and genetic findings. The choice of treatment is complete resection, and further treatment options can be considered. Herein, we describe a case of successful surgical treatment of a 23-year-old man with recurrent malignant esophageal GNET.

Characterization, survival analysis, and expression of IGFR in tumor samples from patients diagnosed with Ewing family tumors treated at the Barretos Cancer Hospital / Caracterização, análise de sobrevida e expressão de IGFR nas amostras tumorais dos pacientes com diagnóstico dos tumores da família Ewing tratados no Hospital de Câncer de Barretos

ABSTRACT OBJECTIVES: Study the clinical characteristics of patients diagnosed with Ewing family tumors (EFTs) and survival analysis based on risk criteria and expression of the surface protein known as insulin-like growth factor (IGFR). METHODS: This was a retrospective cohort study based on clinical data from 77 patients diagnosed with EFTs treated by the Department of Pediatric Oncology at the Barretos Cancer Hospital in a period between 2003 and 2012. Biological samples of patients were examined for the presence of the surface receptor IGFR. RESULTS: The overall survival rate (OSR) of patients included in the study was 45% at five years, and EFS was 30% at five years. Metastasis at diagnosis was present in 44.2% of the sample; 88.2% of the sample was male (p < 0.001). The evaluation of the expression of IGFR in biological samples of patients was associated with the variable metastasis at diagnosis (p < 0.001). Worse prognosis was observed in patients with extrapulmonary metastasis (p = 0.009). The local treatment of neoplasia presented better prognosis in patients undergoing local surgical treatment (p < 0.001). CONCLUSIONS: These results showed a higher incidence of metastasis at diagnosis in patients with EFTs treated at the Barretos Cancer Hospital (BCH). Extrapulmonary metastases were a negative prognostic factor in this study. Surgical treatment of the primary tumor was a factor for better prognosis. Strong expression of IGFR was more frequent in patients with metastases at diagnosis, but did not represent a prognostic factor for EFTs.

RESUMO OBJETIVO: Estudar as características clínicas dos pacientes com diagnóstico de tumores da família Ewing (TFEs) e analisar a sobrevida baseada em critérios de risco e expressão da proteína de superfície conhecida como fator de crescimento semelhante à insulina (IGFR). MÉTODOS: Estudo de coorte retrospectivo, com base em dados clínicos de 77 pacientes com diagnóstico de TFEs tratados pelo Departamento de Oncologia Pediátrica do Hospital de Câncer de Barretos entre 2003 e 2012. Amostras biológicas de pacientes foram examinadas quanto à presença do receptor de superfície IGFR. RESULTADOS: Em cinco anos, a taxa de sobrevida global (SG) dos pacientes incluídos no estudo foi de 45% e a taxa de sobrevida livre de eventos (SLE) foi de 30%. Metástases no momento do diagnóstico foram observadas em 44,2% da amostra, sendo que desses, 88,2% eram do sexo masculino (p < 0,001). A avaliação da expressão de IGFR nas amostras biológicas dos pacientes apresentou associação com a variável metástase ao diagnóstico (p < 0,001). Pacientes com metástase extrapulmonar apresentaram pior prognóstico (p = 0,009). A modalidade de tratamento local da neoplasia apresentou melhor prognóstico em pacientes submetidos ao tratamento cirúrgico local (p < 0,001). CONCLUSÃO: Os resultados evidenciaram uma maior incidência de metástase ao diagnóstico nos pacientes com diagnóstico de TFEs tratados no Hospital de Câncer de Barretos. A metástase de localização extrapulmonar foi fator de pior prognóstico no estudo. O tratamento cirúrgico do tumor primário foi fator de melhor prognóstico. A expressão forte de IGFR esteve mais presente nos pacientes com metástase ao diagnóstico, porém não se mostrou como fator prognóstico nos TFEs.

Embryonic Tumor with Abundant Neuroepithelium and True Rosettes (ETANTR): Case Report and Literature Review

The embryonal tumor with abundant neuropil and true rosettes (ETANTR) is an extremely rare variant of the primitive neuroectodermal tumor (PNET). About 80 cases have been reported since its first description in the literature, in 2000. The ETANTR occurs in very young patients, especially children under 6 years of age. It is found mainly in the cerebral cortex. Headache, focal neurological signs, seizures, increased head circumference and psychomotor developmental delay are the most frequent symptoms of ETANTR. Histologically, it displays the features of an ependymoblastoma and a neuroblastoma, showing areas of neuroepithelium fibrillar rosettes with ependymoblastic zones and interposed undifferentiated neuroepithelial cells. The ETANTR is distinguishable from other embryonal tumors due to the abundance of neuroepithelium. Genetic studies have demonstrated the presence of polysomy of chromosome 2 and chromosome 19q13.42 amplification. This is an extremely aggressive tumor with a mean survival ranging from 9 to 48 months. We present the first report in Brazil, published in indexed literature, of an ETANTR case involving a young child.

O tumor embrionário com neurópilo abundante e rosetas verdadeiras (TENARV) é uma variante muito rara do tumor neuroectodérmico primitivo (TNEP), com cerca de 80 casos publicados desde a sua primeira descrição na literatura, em 2000. O TENARV ocorre em pacientes muito jovens, especialmente crianças abaixo de 6 anos de idade, atingindo principalmente o córtex cerebral. Cefaleia, sinais focais, crise convulsiva, aumento do perímetro cefálico e atraso do desenvolvimento psicomotor são os sintomas mais frequentes da TENARV. Histologicamente, este tipo de tumor apresenta as características combinadas de um ependimoblastoma e um neuroblastoma, demonstrando áreas de neuroepitélio fibrilar com rosetas ependimoblásticas de permeio e zonas de células neuroepiteliais indiferenciadas. O TENARV é distinguível de outros tumores embrionários pela abundância de neuroepitélio. Estudos genéticos demonstram a presença de polissomia do cromossomo 2 e amplificação do cromossomo 19q13.42. Trata-se de um tumor extremamente agressivo, com sobrevida média entre 9 e 48 meses. Apresentamos o primeiro relato brasileiro, publicado em literatura indexada, de um caso de TENARV acometendo uma criança jovem.

Paraganglioma de cuerpo carotideo / Carotid body paraganglioma

Contexto: Los paragangliomas del cuerpo carotideo son tumores adrenales de mayor frecuencia entre los paragangliomas; en términos generales, son infrecuentes y deben ser diagnosticados por técnicas de imagen para caracterizar la anatomía y grado de invasión del tumor, a fin de su planificación quirúrgica. Objetivo: evaluar la experiencia institucional del Hospital Carlos Andrade Marín en el manejo de los tumores del cuerpo carotideo. Sujetos y métodos: el estudio retrospectivo analizó los registros médicos de 26 pacientes con paragangliomas del cuerpo carotideo tratados en el Hospital Carlos Andrade Marín de Quito, en un periodo de 21 meses; se complementa con una revisión de la bibliografía. Resultados: del total del universo estudiado el paragaglioma se presentó en 20 mujeres que corresponde al 76%, y en 6 hombres que corresponde al 23. El tamaño promedio del tumor en los pacientes fue de 3,7 ± 1,4 cm. Según la clasificación de Shamblin el paraganglioma en el 74% de los pacientes se encontraba en clasificación ll, el 22% se encontraban en clasificación l, mientras que el 37% se encontraban en clasificación lll. El promedio de sangrado en los pacientes fue 331 ± 284 ml .El tiempo quirúrgico fue de 112 ± 37 minutos. La resección completa del tumor se realizó en el 100 % de los pacientes, en donde en el 7,4% hubieron complicaciones de lesion del nervio craneal y otras complicaciones ocurrieron en el 7,4 % de los pacientes. Conclusión: la experiencia del equipo quirúrgico del Hospital Carlos Andrade Marín ofreció una alternativa segura, con resultados satisfactorios y baja incidencia de secuelas a largo plazo. (AU)

Context: The paragangliomas of the carotid body are adrenal tumors of greater frequency among the paragangliomas; In general terms, they are infrequent and must be diagnosed by imaging techniques to characterize the anatomy and degree of tumor invasion, in order to plan their surgery. Objective: To evaluate the institutional experience of the Hospital Carlos Andrade Marin in the managemen of tumors of the carotid body. Subjects and methods: The retrospective study analyzed the medical records of 26 patients with paragangliomaof the carotid body treated in the Carlos Andrade Marín Hospital in Quito, in a period of 21 months; It icomplemented by a review of the bibliography. Results: of the total universe studied, paragaglioma was present in 20 women, corresponding to 76%, and in 6 men, corresponding to 23%. The average tumor size in the patients was 3.7 ± 1.4 cm. According to the classification of Shamblin paraganglioma in 74% of patients were in classification II, 22% were in classification I, while 37% were in classification III. The average bleeding in the patients was 331 ± 284 ml. The surgical time was 112 ± 37 minutes. Complete resection of the tumor was performed in 100% of the patients, where in 7.4% there were cranial nerve lesions and other complications occurred in 7.4% of the patients. Conclusions: The experience of the surgical team of the Hospital Carlos Andrade Marín offers a safe alternative, with satisfactory results and low incidence of long-term sequelae. (AU)

Pediatric Ewing's Sarcoma/Primitive Neuroectodermal Tumor (ES/PNET) Developed in the Small Intestine: A Case Report / 임상소아혈액종양

Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are a group of malignant tumors with varying degrees of neuroectodermal differentiation. Although it may develop in any organs, ES/PNET originating from small intestine is exceedingly rare. We experienced a 9-year-old girl presenting with abdominal pain, melena, and iron deficiency anemia. Imaging work-up showed multiple masses in the small bowel and omentum with disseminated peritoneal seeding nodules, indicating lymphoma as the most likely diagnosis. Pathological reports from explorative diagnostic laparoscopic biopsy showed tumors comprising small round cells with CD99 expression and EWS-FLI1 translocation leading to the diagnosis of ES/PNET. Tumor burden decreased gradually during five consecutive cycles of systemic chemotherapy. The patient received segmental resection of jejunum, followed by adjuvant chemotherapy. This is the first pediatric case of ES/PNET found in small intestine in Korea.

Pediatric Ewing's Sarcoma/Primitive Neuroectodermal Tumor (ES/PNET) Developed in the Small Intestine: A Case Report / 임상소아혈액종양

Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are a group of malignant tumors with varying degrees of neuroectodermal differentiation. Although it may develop in any organs, ES/PNET originating from small intestine is exceedingly rare. We experienced a 9-year-old girl presenting with abdominal pain, melena, and iron deficiency anemia. Imaging work-up showed multiple masses in the small bowel and omentum with disseminated peritoneal seeding nodules, indicating lymphoma as the most likely diagnosis. Pathological reports from explorative diagnostic laparoscopic biopsy showed tumors comprising small round cells with CD99 expression and EWS-FLI1 translocation leading to the diagnosis of ES/PNET. Tumor burden decreased gradually during five consecutive cycles of systemic chemotherapy. The patient received segmental resection of jejunum, followed by adjuvant chemotherapy. This is the first pediatric case of ES/PNET found in small intestine in Korea.

Sarcoma de Ewing extraóseo en espacio epidural / Extraosseous Ewing's sarcoma in spinal epidural space

El sarcoma extraóseo de Ewing pertenece a la familia de tumores neuroectodérmicos que derivan de la cresta neural, característico por su agresividad. Varias localizaciones se han descrito, sin embargo, la presentación epidural es rara. El pronóstico ha mejorado por nuevos esquemas oncológicos y están en estudio otras dianas terapéuticas.

Extraosseous Ewing's sarcoma belongs to the family of neuroectodermal tumors that derive from the neural crest, characteristic of its aggressiveness. Several locations have been described, however,epidural presentation is rare. Prognosis has been improved by new oncological regimens and other therapeutic targets are being studied.

Sellar-Suprasellar Extraventricular Choroid Plexus Papilloma : A Case Report and Review of the Literature

Choroid plexus papillomas (CPPs) are relatively rare neuroectodermal tumors that develop from choroid plexus epithelial cells and are usually restricted to the ventricles. Extraventricular CPPs are very unusual and can be difficult to diagnose and treat. A 50-year-old male patient was admitted to our clinic complaining of headache and visual deterioration. Neurological examination found no abnormalities except decreased light perception and secondary optic atrophy in the left eye. Endocrine testing revealed normal levels of hormones produced by the pituitary and target glands. Magnetic resonance imaging of the brain revealed a huge regular-shaped lesion in the sellar-suprasellar region occupying the sella turcica and extending into the suprasellar cistern and planum sphenoidale. The lesion was completely excised by microsurgery via an ordinary left-sided pterional approach. Histopathology identified the lesion as a choroid plexus papilloma. Following the case report, literature on the origin, differential diagnosis, and treatment of this rare tumor is reviewed.

Disseminated Mycobacterium fortuitum Infection Associated with Venous Access Device.

Mycobacterium fortuitum is an important opportunistic pathogen among the rapidly growing Mycobacteria. Disseminated disease occurs as a consequence of bacteremia linked to vascular catheters, which carry high morbidity and mortality when they occur in immuno-compromised patients. Conventional culture methods often miss these organisms since they may grow more slowly (after 48 h) and are dismissed as skin contaminants because of their morphological resemblance to diphtheroids on grams staining. We report a case of 10 months old child with primitive neuroectodermal tumor who developed disseminated disease with M. fortuitum that was related to an indwelling intravascular device. The isolates were confirmed as M. fortuitum by polymerase chain reaction based DNA sequencing targeting heat shock protein 65 gene. The child was treated with, rifampicin, ethambutol and azithromycin. The patient improved remarkably and became afebrile 2 days after institution of therapy and removal of the catheter. The treatment was given for 3 months.

Ewing's Sarcoma/Primitive Neuroectodermal Tumor of the Uterine Corpus

No abstract available.

A Case of Primary Cutaneous CD30+ Anaplastic Large Cell Lymphoma, Small Cell Variant / 대한피부과학회지

Primary cutaneous anaplastic large cell lymphoma (PCALCL) is a rare cutaneous T-cell lymphoma. Most cases are composed of large anaplastic cells. However, it presents a wide spectrum of histologic patterns. In the small cell variant, a small-sized pleomorphic cell morphology can be seen. A 74-year-old woman presented with an 8-month history of asymptomatic ulcerative plaque and satellite nodule on the right calf. Her past medical history was not specific. The histologic findings on punch biopsy specimens showed a malignant small round cell tumor on both lesions. The tumor cells had large pleomorphic nuclei with multinucleation and some eosinophilic cytoplasm. We performed immunohistochemical staining to rule out neuroectodermal tumor, neuroendocrine tumor, melanoma, lymphoma, and so on. However, the staining results were negative for pancytokeratin, CD3, CD20, CD99, chromogranin A, synaptophysin, CD56, ALK, HMB45, desmin, kappa, lambda, myoglobin, and S-100 protein. CT, MRI, and PET-CT were negative for extracutaneous involvement. Total excision was done, and additional immunohistochemical staining was performed to confirm the origin of the tumor. Staining results for vimentin, LCA, CD4, and CD30 were positive. We concluded that these findings were consistent with the small cell variant CD30+ PCALCL, which occurs rarely.

A Case of Primary Cutaneous CD30+ Anaplastic Large Cell Lymphoma, Small Cell Variant / 대한피부과학회지

Primary cutaneous anaplastic large cell lymphoma (PCALCL) is a rare cutaneous T-cell lymphoma. Most cases are composed of large anaplastic cells. However, it presents a wide spectrum of histologic patterns. In the small cell variant, a small-sized pleomorphic cell morphology can be seen. A 74-year-old woman presented with an 8-month history of asymptomatic ulcerative plaque and satellite nodule on the right calf. Her past medical history was not specific. The histologic findings on punch biopsy specimens showed a malignant small round cell tumor on both lesions. The tumor cells had large pleomorphic nuclei with multinucleation and some eosinophilic cytoplasm. We performed immunohistochemical staining to rule out neuroectodermal tumor, neuroendocrine tumor, melanoma, lymphoma, and so on. However, the staining results were negative for pancytokeratin, CD3, CD20, CD99, chromogranin A, synaptophysin, CD56, ALK, HMB45, desmin, kappa, lambda, myoglobin, and S-100 protein. CT, MRI, and PET-CT were negative for extracutaneous involvement. Total excision was done, and additional immunohistochemical staining was performed to confirm the origin of the tumor. Staining results for vimentin, LCA, CD4, and CD30 were positive. We concluded that these findings were consistent with the small cell variant CD30+ PCALCL, which occurs rarely.

Utility of Transmission Electron Microscopy in Small Round Cell Tumors

Small round cell tumors (SRCTs) are a heterogeneous group of neoplasms composed of small, primitive, and undifferentiated cells sharing similar histology under light microscopy. SRCTs include Ewing sarcoma/peripheral neuroectodermal tumor family tumors, neuroblastoma, desmoplastic SRCT, rhabdomyosarcoma, poorly differentiated round cell synovial sarcoma, mesenchymal chondrosarcoma, small cell osteosarcoma, small cell malignant peripheral nerve sheath tumor, and small cell schwannoma. Non-Hodgkin\'s malignant lymphoma, myeloid sarcoma, malignant melanoma, and gastrointestinal stromal tumor may also present as SRCT. The current shift towards immunohistochemistry and cytogenetic molecular techniques for SRCT may be inappropriate because of antigenic overlapping or inconclusive molecular results due to the lack of differentiation of primitive cells and unavailable genetic service or limited moleculocytogenetic experience. Although usage has declined, electron microscopy (EM) remains very useful and shows salient features for the diagnosis of SRCTs. Although EM is not always required, it provides reliability and validity in the diagnosis of SRCT. Here, the ultrastructural characteristics of SRCTs are reviewed and we suggest that EM would be utilized as one of the reliable modalities for the diagnosis of undifferentiated and poorly differentiated SRCTs.

A Case of Primitive Neuroectodermal Tumor in the Nasal Cavity

A primitive neuroectodermal tumor is a highly malignant, small, round-cell tumor characterized by a neuroectodermal origin and poor prognosis. These tumors are found in nervous tissue in children and adolescents. The thoracopulmonary region is known to be the most common site of this disease, and it is rare that a primitive neuroectodermal tumor would occur in the nasal cavity. We report a case of a primitive neuroectodermal tumor in the left nasal cavity with a review of relevant literature.