Importancia del diagnóstico histopatológico en el tratamiento de las lesiones del tronco cerebral en adultos / Relevance of histopathological diagnosis in the treatment of brainstem lesions in adults

Los tumores del tronco cerebral son infrecuentes en la población adulta. Las controversias surgen cuando se considera la necesidad de confirmar el diagnóstico histopatológico en esta área elocuente del cerebro, balanceando los beneficios de obtener un diagnóstico certero y las desventajas de los procedimientos invasivos. Existen escasas publicaciones acerca de su tratamiento quirúrgico en adultos, todas series pequeñas analizadas retrospectivamente. Presentamos nuestra experiencia con el propósito de contribuir al proceso de toma de decisiones. Diez de 13 pacientes fueron intervenidos. Las lesiones se clasificaron en focales (n:7), infiltrativa difusa (n:1), tectal (1) y exofítica (1). El estado neurológico según la escala Karnofsky Performance Status fue ≥ 70 en 6 casos y < 70 en 7. Las muestras fueron obtenidas mediante abordaje microquirúrgico directo o por biopsia estereotáctica. Los hallazgos histopatológicos fueron confirmados en todos los casos: astrocitoma pilocítico (n:1), glioma de bajo grado (n:1), glioblastoma (n:1), hemangioblastoma celular (n:1), subependimoma (n:1), disgerminoma (n:1), y lesiones pseudotumorales (n:4, 3 cavernomas, 1 pseudotumor inflamatorio). La amplia variedad de hallazgos patológicos en esta localización en adultos exige una precisa definición histopatológica, que no solo determina la terapéutica adecuada sino que también previene las consecuencias potencialmente catastróficoas de los tratamientos empíricos.

Brainstem tumors are uncommon beyond childhood. Controversies arise regarding the need of histological diagnosis in this eloquent area of the brain, weighting the benefits of a reliable diagnosis against the disadvantages of invasive procedures. There are scant publications about the surgical management of brainstem tumors in adults, all of them involving small retrospective cohorts. We are reporting our experience with the aim of contributing to the decision making process. Out of a series of 13 patients, 10 were approached surgically. According to Guillamo´s classification the lesions were: focal (n:7), diffuse infiltrative (n:1), tectal (n:1), and exophytic (n:1). According to the Karnofsky Performance Status scale, the neurological status was ≥ 70 in 6 cases and < 70 in 7. Histopathology was confirmed in all 10 treated cases and the samples were obtained by a direct microsurgical approach or by stereotactic biopsy. Histopathological findings were: pilocytic astrocytoma (n:1), low grade glioma (n:1), glioblastoma (n:1), cellular haemangioblastoma (n:1), subependimoma (n:1), pseudotumoral lesions (n:4; 3 cavernomas, 1 inflammatory pseudotumor), and disgerminoma (n:1). As a broad variety of pathologies could be found in this brain localization, an accurate histopathological definition can not only determine the adequate therapy, but also avoid the disastrous consequences of empiric treatments.

Tumores de tronco cerebral en niños tratados con radioterapia / Radiation therapy in the treatment of brain-stem tumors in children

Introduction: Due to their location, tumors of the trunk (TT) present a high surgical risk and the diagnosis is usually made by imaging. In Chile, these cases are treated according to the PINDA Program (national treatment guide for pediatric tumors). All patients receive radiotherapy (RT) after diagnosis. The aim of this study is to evaluate the treatment results for TT at the National Cancer Institute (NCI) between 1993 and 2011. Patients and Method: A retrospective review of patients diagnosed with TT at NCI was conducted. Patient population, symptoms, treatment received and overall survival are described. Prognostic factors were analyzed. Results: From November 1993 to December 2011, 70 children were referred for possible RT, 68 of them actually received it. The median age at diagnosis was 7 years old. In June 2012, out of 70 patients, 60 were deceased, all due to disease progression. The median survival of patients who received RT (68 patients) was 8.5 months from the end of treatment; the survival rates at 1, 2 and 3 years was 31.5 percent 14.3 percent and 12.8 percent respectively. Univariate analysis showed that survival was affected by the MRN high resolution imaging (p = 0.07) and by the diffuse tumor pattern (p = 0.025). Multivariate analysis showed survival is affected by the MRN high resolution imaging (p = 0.011) and a higher dose of RT protector (p = 0.015). Conclusions: The poor results obtained in the treatment of TT with RT at the INC are similar to those reported by other centers. Further explorations regarding other treatment options based on combined therapy using RT are needed.

Introducción: Los tumores de tronco (TT), por su ubicación, conllevan un alto riesgo quirúrgico, por lo que generalmente el diagnóstico se realiza por imágenes. En Chile se tratan según el programa PINDA (guía para tratamiento de tumores pediátricos nacional). Todos reciben radioterapia (RT) luego del diagnóstico. El objetivo de esta publicación es evaluar los resultados de tratamiento de los TT en el Instituto Nacional del Cáncer (INC) en el período 1993-2011. Pacientes y Método: Revisión retrospectiva de los pacientes tratados con el diagnóstico de TT en el INC. Se describe la población de pacientes, síntomas de presentación, tratamientos recibidos y sobrevida global. Se exploraron factores pronósticos. Resultados: Desde noviembre de 1993 hasta diciembre de 2011 fueron derivados para consideración de RT 70 niños, de ellos 68 la recibieron. La mediana de edad al diagnóstico fue de 7 años. A junio de 2012, del total de 70 pacientes, 60 se encontraban fallecidos, todos por progresión de enfermedad. La mediana de sobrevida, de los pacientes que recibieron RT (68 pacientes), fue de 8,5 meses desde el fin de esta; la sobrevida a 1, 2 y 3 años fue de 31,5 por ciento, 14,3 por ciento, 12,8 por ciento respectivamente. Al análisis univariado, fue peor para la sobrevida, el alto grado a la imagen de RNM (p = 0,07) y el patrón tumoral difuso (p = 0,025). Al análisis multivariado, es peor para la sobrevida el alto grado a la imagen de RNM (p = 0,011) y protector una mayor dosis de RT (p = 0,015). Conclusiones: Los pobres resultados obtenidos en el tratamiento con RT de TT en el INC son similares a los reportados por los otros centros. Sería sin duda interesante explorar otras alternativas de tratamiento en base a tratamientos combinados con RT.

Tumefactive demyelinating lesions: A Clinicopathological correlative study.

Tumefactive demyelinating (TDL) lesions are focal zones of demyelination in the central nervous system and they often mimic the neuroimaging features of an intraxial neoplasm. In this report we describe the clinical, neuroimaging and neuropathological features of six cases of TDL. Only in two patients the neuroimaging features in MRI (magnetic resonance imaging) scans were suggestive of TDL while in the other four cases a diagnosis of glioma was suggested. In order to establish a confirmatory diagnosis neuronavigation/stereotactic biopsy was undertaken and the diagnosis of TDL was established in all six cases at histopathology. Two out of six patients did not respond to the conventional corticosteroid therapy and they were treated with plasma exchange. It is being concluded that neuronavigation biopsy, though provide only a small amount of tissue, and is extremely useful in making the diagnosis of TDL.

Stereotaxic gamma knife surgery in treatment of critically located pilocytic astrocytoma: Preliminary result

Low-grade gliomas are uncommon primary brain tumours, located more often in the posterior fossa, optic pathway, and brain stem and less commonly in the cerebral hemispheres. Two patients with diagnosed recurrent cystic pilocytic astrocytoma critically located within the brain [thalamic and brain stem] were treated with gamma knife surgery. Gamma knife surgery did improve the patient's clinical condition very much which remained stable later on. Progressive reduction on the magnetic resonance imaging studies of the solid part of the tumour and almost disappearance of the cystic component was achieved within the follow-up period of 36 months in the first case with the thalamic located lesion, and 22 months in the second case with the brain stem located lesion. Gamma knife surgery represents an alternate tool in the treatment of recurrent and/or small postoperative residual pilocytic astrocytoma especially located

"La obstrucción estaba abajo": tumores de la médula espinal e hipertensión intracraneal

Aumento de la presión intracraneal, hidrocéfalo y papiledema son observados ocasionalmente en pacientes portadores de tumores medulares en la región cervical o en la unión craneocervical, y entre otros, la obstrucción mecánica de la circulación del líquido cefalorraquídeo es asumida como responsable para tales síntomas y signos. No obstante, la hipertensión intracraneal es un raro fenómeno en tumores espinales de localización tóracolumbar. Los autores describen dos pacientes en quienes un tumor en tal localización (schwannoma benigno y paraganglioma) se asoció a síntomas de hipertensión intracraneal, hidrocefalia y papiledema. Se piensa que este tipo de lesiones puede interferir activamente en la dinámica del flujo del líquido cefalorraquídeo en razón de que la ocupación de espacio impide la expansión del saco dural y espacio subaracnoideo espinal que se piensa juegan algún papel en la compensación de los cambios de volumen y la presión intracraneal

Increased intracranial pressure, hydrocephalus and papilledema are occasionally observed in patients harboring spinal tumors in the cervical region or at the craniocervical junction, and among others, the mechanical obstruction to the cerebrospinal fluid circulation is assumed to be responsible for such symptoms and signs. However, increased intracranial pressure is very rare in spinal tumors located in the thoraco-lumbar region. Two patients are described by the authors in whom a benign thoracolumbar tumor (benign schwannoma and paraganglioma) was associated with symptoms of increased intracranial pressure, hydrocephalus and papiledema. It has been suggested that this kind of lesions could actively interfere with cerebrospinal fluid dynamics by their mass effect, especially by preventing the expansion of the dural sac and spinal subarachnoid space which may play some roce in compensating for volume changes and intracranial pressure

Pediatric intramedullary schwannoma without neurofibromatosis.

Pediatric intramedullary schwannoma without neurofibromatosis is extremely rare with only five cases reported so far. We present this rare finding in an 8-year-old boy who presented with a sudden onset of weakness in all limbs. An intraoperative diagnosis of schwannoma enabled us to carry out a total excision of the tumor, which resulted in near complete recovery at 18 months follow-up. Although rare, this diagnosis should be considered when a child presents with a solitary intramedullary tumor, since its total resection can be achieved improving surgical outcome.