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.

Description of a neural sheath tumor of the trigeminal nerve: immunohistochemical and electron microscopy study

CONTEXT: Malignant neural sheath tumors of the trigeminal nerve affecting the nasal cavity and the paranasal sinuses are extremely rare. With conventional optical microscopy, their identification is difficult, and it is necessary to confirm them by means of electron microscopy and immunohistochemical techniques. CASE REPORT: The patient was a 41-year-old woman with a ten-month progressive history of pain followed by painful edema in the left facial region, and with symptoms of bleeding, secretion and nasal obstruction. Studies with imaging methods suggested the presence of an expansive process in the left nasal and paranasal cavities. In the biopsy, the histopathological findings from optical microscopy were suggestive of a tumor of neural origin in the trigeminal nerve. Immunohistochemical and electron microscopy studies confirmed that it was a malignant tumor of the neural sheath of the trigeminal nerve. We describe the clinical, radiological, and histological features of this tumor and review the literature.

CONTEXTO: O tumor maligno da bainha neural do trigêmeo que acomete a cavidade nasal e os seios paranasais é extremamente raro. A microscopia óptica habitual sua identificação é difícil, sendo necessária a confirmação através de microscopia eletrônica e de técnicas imunoistoquímicas. RELATO DE CASO: A paciente era uma mulher de 41 anos com história de 10 meses de progressiva dor seguida de edema álgico em região facial à esquerda, e de sintomas de sangramento, secreção e obstrução nasal. Estudos com métodos de imagem sugeriam a presença de processo expansivo em cavidades nasais e paranasais à esquerda. A biopsia, os achados histopatológicos à microscopia óptica foram sugestivos de tumor de origem neural no trigêmeo. Estudos imunoistoquímico e por microscopia eletrônica confirmaram se tratar de neoplasia maligna da bainha neural do trigêmeo. Descrevemos as características clínicas, radiológicas e histológicas deste tumor, e revisamos a literatura.