Tumor de nervio periférico: una localización poco habitual / Peripheral nerve tumor: an unusual location

Benign tumors of peripheral nerves called Schwannomas or neurilemomas, correspond to a rare pathology, represent 5% of all tumors of the upper extremity, and affects, mainly, the ulnar nerve. The incidence of Schwannoma in the literature for the radial nerve is not clearly established given the infrequency of its presentation, there are only reports of isolated cases The following publication presents the case of a male patient with a radial nerve schwannoma. Clinically, presents increased painful volume on palpation, well delimited, of soft consistency in the distal third of the right arm of 3 years of evolution, without history of previous trauma, without irradiation, or paresthesia, with preservation of motor and sensory function of radial, median and ulnar nerve. Considering that the involvement of the radial nerve is very low frequency, a review is carried out in PubMed, in the last 10 years, there are only 9 studies, grouped in case reports and imaging studies for diagnosis.

Tumor benigno de la vaina neural en rodilla. Reporte de caso y revisión bibliográfica / Knee neural sheath benign tumor. Case report and bibliographic revision

El schwannoma es el tumor benigno de nervio periférico más frecuente. Su presencia en los nervios de miembros inferiores es excepcional, donde representan el 1% de todos los schwannomas. Presentamos el caso de una mujer de treinta y un años que consulta por dolor en la cara anterior de la rodilla derecha, donde se palpa una masa blanda, dolorosa, de 1 cm aproximadamente y dolor en interlínea externa con signo de McMurray positivo. La RM evidenció una estructura ovoidea de señal quística, superficial al retináculo medial en su tercio proximal, de 10 × 8 × 8 mm y lesión del menisco externo en su tercio medio. Se realizó tratamiento artroscópico de la lesión meniscal externa y por vía abierta la exéresis marginal quirúrgica del tumor de partes blandas, con diagnóstico histopatológico de schwannoma. Los schwannomas de nervio periférico, aunque sean una entidad poco frecuente, deben considerarse en el diagnóstico diferencial de las masas dolorosas de la rodilla. Su tratamiento es la exéresis quirúrgica

Schwannoma is the most common benign peripheral nerve tumor, its presence being exceptional in the nerves of the lower limbs, where it represents 1% of all schwannomas. We present the case of a thirty-one-year-old woman who consulted for anterior knee pain, where a soft, painful mass of approximately 1cm and pain on the lateral joint line was assessed. McMurray's sign was positive. MRI showed an ovoid structure with a cystic signal, superficial and proximal to the medial retinaculum, measuring 10 × 8 × 8 mm and a tear in the body and posterior horn of the lateral meniscus. Arthroscopic treatment for the lateral meniscus tear and open surgical marginal excision of the soft tissue tumor were performed, with pathological diagnosis of schwannoma. Peripheral nerve schwannomas, although a rare entity, should be considered in the differential diagnosis of painful knee masses, their treatment being surgical excision

Tumor gigante de vaina neural / Giant tumor from the nerve sheath

Resumen: El schwannoma es un tumor benigno derivado de la vaina neural de las células de Schwann. Habitualmente suele ser pequeño y solitario, siendo más frecuente en los pares craneales y en la médula espinal, aunque menos frecuente en las extremidades. Se han descrito casos de aparición en las extremidades (principalmente superiores). Son muy raros los casos de schwannomas de gran tamaño sin relación con la neurofibromatosis. Presentamos a una paciente de 25 años de edad, con un schwannoma gigante que invadía desde la región isquiática al tríceps sural.

Abstract: A schwannoma is a benign nerve sheath tumor derived from Schwann cells. They are usually small and solitary tumors more frequently localized in cranial nerves and the spinal cord and rarely in the limbs. Some cases have been reported involving extremities (mainly the upper ones) but with a small size. Cases of big size schwannomas unrelated to a neurofibromatosis are very rare. We report the case of a 25 year old patient, with a giant schwannoma which invaded the ischiatic region reaching the triceps surae.

Tumor maligno de vaina de nervio periférico: reporte de caso / Malignant peripheral nerve sheath tumor: case report

Se presenta un caso de tumor sacro voluminoso con características de Tumor Maligno de Vaina de Nervio Periférico (MPNST) que tras una resección inicial y recidiva se reintervino y trató con radioterapia complementaria. Tras ocho años se ha observado una buena evolución.

A case of voluminous sacral tumor with Malignant Peripheral Nerve Sheath Tumor (MPNST) characteristics is reported, that after a first resection and later recurrence is reoperated and treated with complementary radiotherapy. After eight years a good evolution has been observed.

Tumor maligno da bainha do nervo periférico: relato de caso / Malignant peripheral nerve sheath tumor: case report

JUSTIFICATIVA E OBJETIVOS: O tumor maligno da bainha do nervo periférico (TMBNP), anteriormente chamado de schwannoma maligno, é um tumor raro, representando até 10% dos sarcomas. Em aproximadamente 50% dos casos associam-se à neurofibromatose tipo 1 (NF1) ou doença de von Recklinghausen. São tumores agressivos e frequentemente resistentes à quimioterapia.O objetivo deste estudo foi a exposição de um caso de TMBNP enfatizando a importância da imuno-histoquímica para o diagnóstico. RELATO DO CASO: Paciente do sexo masculino, 54 anos, internado por dor abdominal, desconforto pós-prandial, lombociatalgia com irradiação ao membro inferior direito e lesões nodulares no fígado. A investigação revelou massa retroperitoneal com necrose e lesões líticas no sacro e coluna vertebral. As biópsias do sacro e hepática revelaram células mesenquimatosas, fusiformes, que coravam para S-100 na imuno-histoquímica. Admitido o diagnóstico de TMBNP com origem em massa retroperitoneal com metastatização óssea e hepática. O paciente foi referenciado à oncologia sendo tratado com quimioterapia paliativa. CONCLUSÃO: A raridade do TMBNP explica a importância da divulgação deste caso, informando os clínicos, diminuindo o tempo para o diagnóstico e melhorando substancialmente as probabilidades de cura e a sobrevida. Este caso é interessante também por não estar associado à NF1 e por não se ter determinado o nervo periférico de origem, assentando o diagnóstico no resultadodo estudo anatomo-histológico.

BACKGROUND AND OBJECTIVES: The malignant peripheral nerve sheath tumor (MPNST), previously designated malign schwannoma is a rare tumor, accounting up to 10% of the soft tissues sarcomas. In approximately 50% of the cases there is anassociation with neurofibromatosis -1 (NF1) or von Recklinghausen disease. This tumor is extremely aggressive and frequently resistant to chemotherapy. The purpose of this study is to describe a clinical case of MPNST emphasizing the importance of the immunohistochemistry to accomplish the diagnosis. CASE REPORT: A male patient, 54 years-old, admitted to the hospital with abdominal pain, postprandial epigastric discomfort, lumbosacral pain radiating to the right leg and nodular hepatic lesions. The clinical investigation revealed retroperitoneal mass with areas of necrosis and disperse lytic lesions on the sacrum and vertebral column. The hepatic and sacral biopsies revealed mesenchymal cells, spindled, which stained positively to S-100 in the immunohistochemistry. It was diagnosed MPNST,originated in the retroperitoneal mass metastasized to liver and bone. The patient was oriented to oncology being treated with palliative chemotherapy. CONCLUSION: The rarity of MPNST explains the importance of divulgating this case in order to inform the clinicians, diminishing the time to diagnosis, improving treatment and survival probabilities. This case report is also interesting because there was no association with NF1, and because it wasn't possible to identify the original peripheral nerve. The diagnosis was made due to the histological study performed.

Tumor maligno de la vaina del nervio periférico del mediastino en un paciente con neurofibromatosis tipo 1 / Mediastinal malignant peripheral nerve sheath tumor in a neurofibromatosis type 1 patient

El tumor maligno de la vaina del nervio periférico (TMVNP), es una neoplasia maligna originada en las células de Schwan de la vaina de revestimiento del nervio periférico. Describir el caso de un hombre con neurofibromatosis tipo 1 (NF1), quién presentó un TMVNP de bajo grado, y realizar una discusión sobre esta enfermedad. Hombre de 28 años, con antecedente de NF1 diagnosticada a los 15 años de edad, con dolor pleurítico izquierdo, disnea y pérdida de peso de 10 meses de evolución. Al examen de tórax, se observó marcada hipercifosis dorsal con disminución del murmullo pulmonar. La radiografía de tórax y tomografía axial computarizada (TAC), evidenciaron gran masa radioopaca bien delimitada en mediastino posterior. Por lo anterior, se realizo biopsia por punción con aguja gruesa guiada por TAC, en la cual se identificó una neoplasia maligna mesenquimal. Se decidió realizar resección del tumor a través de toracotomía posterolateral, en la que se obtuvo gran masa de 8x9x9 cm, de superficie externa irregular, pardo-violácea y consistencia firme. El estudio histopatologico e inmunofenotípico concluyo el diagnóstico de TMVNP en mediastino posterior Grado 1. Posterior a la cirugía, el paciente se encuentra asintomático. Se presentó un caso de TMVNP originado en un paciente con NF1, presentación que generalmente cursa con peor pronóstico, además se realizo una breve revisión de los aspectos más relevantes de esta enfermedad, algunos de los cuales han tenido un avance vertiginoso en años recientes.

The malignant peripheral nerve sheath tumor (MPNST) is a malignant neoplasm originated in the Schwan cells of the periferic nerves sheath. We describe a case of a man with Neurofibroatosis Type 1 (NF1), who developed a low grade MPNST, and subsequent to a discussion of this disease. 28-year-old Man with pleuritic pain in the left hemithorax, dyspnea and weight loss, with a previous diagnosis of NF1, from the age of 15 and a family history of NF1. At chest examination the patient had an intense thoracic kyphosis, with a decline in the ventilation of the inferior two thirds of the left hemithorax, where a dull sound to percusión was also found. The chest X rays showed a large radiopaque and well delimited mass in the posterior mediastinum, that pushed the cardiovascular structures to the anterior region, which was also documented by chest computed tomography (CT). In view of the above, a puncture biopsy was performed with thick needle guided by CT, from where a malignant mesenhymal neoplasm was identified. It was decided to perform the resection of the tumor of the left posterior mediastinum, by left posterior lateral thoracotomy, in which a large mass of 8x9x9 cm was obtanied, with irregular external surface, brown-violet, and firm. The histopathological and inmunophenotypic study concluded the diagnosis of MPNST in the posterior mediastinum grade 1. Following surgery the patient was asymptomatic. We present a case of MPNST which originated in a patient with NF1, who would usually have a worse prognosis. A brief review of the more relevant aspects of this disease was also reported, some of which have shown important progress in recent years.

A 10 year unsuspected lumbar schwannoma: a case report / Un schwannoma lumbar insospechado por 10 años: reporte de un caso

One case of unsuspected schwannoma is reported in a 69-year old man with chronic lumbosacral pain. The tumour had been mistaken for a lumbar lipoma for a decade. The definitive diagnosis was established after surgery based on the characteristic histopathological findings. The purpose of this report is to alert primary care physicians to peripheral sheath nerve tumours, in addition to highlight the role of pain and image features in the suspicion of tumours with longterm evolution.

Se relata un caso de schwannoma insospechado en un hombre con dolor lumbosacral crónico. El tumour había estado equivocado por el lipoma lumbar durante una década. El diagnóstico definitivo puede establecerse después de la cirugía, con base en los resultados histopatológicos característicos. El propósito de este informe es dar énfasis al conocimiento de médicos del cuidado primario sobre los tumoures de la vaina de nervios periféricos, y resaltar el papel del dolor e de las imágenes en la sospecha de estos tumoures que evolucionan con equívocos diagnósticos a largo plazo.

A case of a sporadic malignant peripheral nerve sheath tumor of the urinary bladder with concomitant in situ urothelial carcinoma treated by transuretheral resection.

Malignant peripheral nerve sheath tumor (MPNST) of the urinary bladder is a very rare clinical entity. The association of such a tumor with urothelial carcinoma is even more unusual. Differential diagnosis between coexisting two distinct primary tumors and carcinosarcoma of the urinary bladder is very important as both the treatment and prognosis vary widely. Herein, we report a case of an MPNST with a concomitant in situ urothelial carcinoma in a 53-year-old man. To our knowledge, this is the first documented case of MPNST of the bladder that is treated by transuretheral resection which is in contrast with the previous reports that used cystectomy.

Revision of gastrointestinal mesenchymal tumors.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal (GI) tract. The advent of target therapy (imatinib mesylate) for GISTs increases the importance of pathologic diagnosis. The previous diagnosis with smooth muscle tumor (leiomyoma or leiomyosarcoma) and nerve sheath tumor (schwannoma) become GISTs after the study with CD117 immunohistochemistry accompanying conventional histologic study in many series. OBJECTIVE: To identify the incidence of GISTs in the patients who were previously diagnosed with smooth muscle or nerve sheath tumors. The histology and immunoreactivity of both newly found and previously diagnosed with GISTs are also studied MATERIAL AND METHOD: A retrospective database identified all patients seen from 1998 to 2006. Patients with mesenchymal tumors of the GI tract and intraabdominal extragastrointestinal tract were selected, 53 cases in total. Clinical and pathological data, treatment, and outcome were analyzed RESULTS: After revision, the total number of GISTs is 42 cases. There were 33 cases previously diagnosed with leiomyosarcoma that became the diagnosis with GISTs (31 cases or 93.9%), due to CD117 positivity. Most of GISTs cases had spindle cell type (26 cases, 61.9%) and only the colon and omentum had predominant mixed cell type. CONCLUSION: GISTs are the most common mesenchymal neoplasm of the stomach and small intestine and are relatively less frequent at other gastrointestinal sites. An increasing awareness of their histologic, immunophenotypic, and molecular features coupled with an evolving understanding of their histogenesis is facilitating our ability to identify these tumors.

Malignant peripheral nerve sheath tumor with divergent differentiation.

A malignant peripheral nerve sheath tumor (MPNST) is an uncommon spindle cell sarcoma accounting for approximately 5% of all soft tissue sarcomas. A 55-year-old female with a right suprarenal tumor showed MPNST with additional foci of epithelioid, rhabdomyoblastic, osteogenic and lipogenic differentiation. Although the capacity of MPNST to undergo epithelioid, rhabdomyoblastic, osteogenic and very rarely lipogenic differentiation is reported in literature, the occurrence of all these differentiation in one case has not been described in literature before. To the best of our knowledge, this is only the second MPNST case with lipomatous differentiation.

Morphological spectrum of peripheral nerve sheath tumors: a series of 126 cases.

By convention, soft tissue tumors include the peripheral nerve sheath tumor (PNST) although they arise from neuroectoderm. PNSTs display a wide spectrum of morphology and biological behavior. Malignant transformation in benign tumors, especially neurofibroma, is an acknowledged phenomenon.This article describes clinico-pathological features of 126 PNSTs with their morphological variants and those associated with neurofibromatosis 1 (NF1) encountered in a single center over a 6-year period. Benign PNSTs were more common [118 (93.65%)] when compared with their malignant counterparts [8 (6.34%)]. Histological variants including plexiform schwannomas and diffuse, plexiform and pigmented forms of neurofibromas, though rare, were observed. Eleven (8.73%) patients with NF1 showed a strong association with plexiform neurofibroma. A malignant transformation in pre-existing neurofibroma was seen in 1 patient with NF1. This series highlights the clinico-pathological spectrum of PNSTs, their morphological variants and the incidence of associated NF1. The importance of detecting plexiform variants lies in their vastly different prognostic implications particularly when occurring in the setting of NF1.

Retrospective analysis of oral peripheral nerve sheath tumors in Brazilians

Traumatic neuroma, neurofibroma, neurilemmoma, palisaded encapsulated neuroma and malignant peripheral nerve sheath tumor (MPNST) are peripheral nerve sheath tumors and present neural origin. The goal of this study was to describe the epidemiological data of oral peripheral nerve sheath tumors in a sample of the Brazilian population. Biopsies requested from the Oral Pathology Service, School of Dentistry, Federal University of Minas Gerais (MG, Brazil), between 1966 and 2006 were evaluated. Lesions diagnosed as peripheral nerve sheath tumors were submitted to morphologic and to immunohistochemical analyses. All cases were immunopositive to the S-100 protein. Thirty-five oral peripheral nerve sheath tumors were found, representing 0.16% of all lesions archived in the Oral Pathology Service. Traumatic neuroma (15 cases) most frequently affected the mental foramen. Solitary neurofibroma (10 cases) was more frequently observed in the palate. Neurofibroma associated with neurofibromatosis type I (2 cases) was observed in the gingival and alveolar mucosa. Neurilemmoma (4 cases) was more commonly observed in the buccal mucosa. Malignant peripheral nerve sheath tumors (3 cases) occurred in the mandible, palate, and tongue. Palisaded encapsulated neuroma (1 case) occurred in the buccal mucosa. The data confirmed that oral peripheral nerve sheath tumors are uncommon in the oral region, with some lesions presenting a predilection for a specific gender or site. This study may be useful in clinical dentistry and oral pathology practice and may be used as baseline data regarding oral peripheral nerve sheath tumors in other populations.

C2 extradural dumbbell neurofibroma in a paediatric patient

Extradural dumbbell shaped neurofibroma in paediatric patients is very rare. A case of extradural dumbbell neurofibroma in a 17-year-old girl who presented with neck pain and slowly progressive neck swelling. On imaging a dumbbell neruofibroma arising from left C2 nerve root was diagnosed. The case is presented here for its rarity, its extremely good postoperative outcome together with its radiological features. Cervical neruofibroma needs to be considered in the differential diagnosis of high cervical myelopathy in children despite its rarity

Neurofibromatose – relato de caso / Neurofibromatosis – case report

A neurofibromatose é uma doença autossômica dominante com um defeito básico nas células da crista neural. Embora existam muitas teorias com respeito à causa da neurofibromatose, a etiologia permanece desconhecida.É caracterizada pela presença de tumores cutâneos e subcutâneos, tumores de nervos e manchas “café com leite”. O diagnóstico é clínico devido ao padrão característico de acometimento cutâneo. A possibilidade de malignização dos neurofibromas em pacientes com NF é motivo de constante preocupação. Nosso objetivo é fazer uma breve revisão de neurofibromatose e descrevermos nosso caso clínico.

Neurofibromatosis is an autosomal dominant disorder that primarily affects the neural crest cells. Although there are many theories regarding the cause of neurofibromatosis, the etiology is still unknown. It is characterised by the presence of on and under skin tumours, nerve tumours and café-au-lait spots. The diagnostic is clinical due to the standard feature of skin involvement.The possibility of the neurofibromas to become malignant in patients with NF is cause for considerable concern. Our aim is to conduct a short review of neurofibromatosis and to describe our clinical case.

Tumor maligno da bainha de nervo periférico em cães: relato de três casos / Malignant peripheral nerve sheath tumor in dogs: three cases report

Descrevem-se os achados anatomoclínicos e imunoistoquímicos dos tumores da bainha de nervos periféricos em três cães atendidos em hospital. Os animais apresentavam sintomatologia variável de acordo com a localização do tumor. A microscopia, as neoplasias eram invasivas e constituídas por células pleomórficas e anaplásicas que variavam de poligonais a fusiformes, arranjadas em padrão sólido difuso, por vezes em paliçada. Foi firmado o diagnóstico de tumor da bainha de nervos periféricos nos três casos.

Anatomo-clinical and immunohistochemical findings on three dogs with peripheral nerve sheath tumors assisted at the veterinary hospital are described. Animals showed different clinical signs depending on the location of the tumor. According to microscopy, neoplasia in all the three case were invasive and comprised of pleomorphic, anaplastic with polygonal to very elongated fusiform shapes arranged in a diffuse solid pattern, forming interwoven bundles in some areas. Immunohistochemistry was used to better classify these tumors. The diagnosis of peripheral nerve sheath tumor was confirmed by histological and immunohistochemical findings.

Paratesticular malignant peripheral nerve sheath tumour: a case report.

Primary malignant peripheral nerve sheath tumours (MPNST) of intrascrotal extra testicular site are extremely rare with only few cases reported in literature. These are highly malignant tumours most often associated with neurofibromatosis. The incidence in general population is 0.001%. A 35-year-old male presented with swelling of the scrotal sac of three months duration. There were no features of neurofibromatosis. The lesion was excised and was diagnosed as MPNST. The patient developed recurrence within two months.

Malignant peripheral nerve sheath tumor in oral cavity--a rare site.

MPNST occurring in oral cavity, which is a rare site for the tumour, in a 35 year old female patient with history of swelling underneath the tongue present since one year diagnosed clinically as ranula is presented here. Histopathological examination of the excised mass showed features of spindle cell sarcoma following which a provisional diagnosis of MPNST was offered. The differential diagnosis considered were leiomyosarcoma, rhabdomyosarcoma and spindle cell variant of squamous cell carcinoma (being the commoner tumour in oral cavity). Immunohistochemistry confirmed neural origin of the tumour. The case is reported in view of the rarity of the lesion in oral cavity.