Indicators of correct targeting in stereotactic biopsy of intracranial lesions.

Background: Confirmation of whether a stereotactic biopsy was performed in the correct site is usually dependent on the frozen section or on novel tumor-specific markers that are not widely available. Immediate postoperative computed tomography (CT) or magnetic resonance (MR) is routinely performed in our service after biopsy. In this retrospective study, we have carefully analyzed these images in an attempt to determine the presence of markers that indicate appropriate targeting. Methods: Medical records and neuroimages of patients who underwent stereotactic biopsy of intracranial lesions were reviewed. The following variables were assessed: age, sex, anatomopathology, lesion site, complications, diagnostic accuracy, and the presence of image markers. Results: Twenty-nine patients were included in this case series. About 96.6% of the biopsies were accurate according to the permanent section. Of the 86.2% of patients with intralesional pneumocephalus on the postoperative images, 51.7% additionally presented petechial hemorrhage. In 13.8% of the cases, no image markers were identified. Conclusion: This is the first report of intralesional pneumocephalus and petechial hemorrhage as indicators of appropriate targeting in stereotactic biopsy. In the majority of the cases, an immediate postoperative head CT, which is widely available, can estimate how adequate the targeting is. To use intralesional pneumocephalus/ petechial hemorrhages as not only postoperative but also as intraoperative markers of appropriate targeting, it is advised that the surgical wound should be temporarily closed and dressed after the biopsy so that the patient can undergo a CT/MR scan and be checked for the presence of theses markers before removing the stereotactic frame.

Thalamic tumors in children: case series from our institution and literature review.

PURPOSE: To describe a case series of children with thalamic tumors treated at our institution in a 5-year period. METHOD: A retrospective and observational study was performed. The records of 15 patients between 2013 and 2018 were analyzed. RESULTS: From 2013 to 2018, 15 patients were treated at our institution. The male to female index was 1.5, and the median age was 8.9 (IQR 4.75-13). Seven (46%) tumors were left-sided, seven (46%) were right-sided, and one (6%) was bilateral. All patients were symptomatic at the time of treatment. Motor deficit was the most common form of presentation (73%). Gross-total resection was performed in two (13.3%) patients, subtotal resection was performed in two other patients (13.3%), and for the rest of the patients (73.3%), the chosen surgical approach was a stereotactic-guided biopsy. The average of procedures was 3.4, mostly related to the treatment for hydrocephalus. Twelve patients (80%) received treatment for hydrocephalus. Nine patients (75%) were treated with ventriculoperitoneal shunts, and four patients (33%) underwent endoscopic third ventriculostomy. High-grade tumors predominated. Grade IV tumors were diagnosed in six patients (40%), followed by grade III in four patients (26.6%), grade II in three (20%) patients, and grade I in two (13.3%) patients. Chemotherapy was given in 93% of the cases, being temozolomide, the most used drug. CONCLUSION: The clinical and surgical approaches for thalamic tumors in children have changed over time. At our institution, the lesser invasive surgical procedures are now being used more frequently.

Pediatric intrinsic brainstem lesions: clinical, imaging, histological characterization, and predictors of survival.

PURPOSE: Brainstem lesions comprise 10-20% of all pediatric brain tumors. Over the past years, the benefits of stereotactic biopsy versus the use alone of MRI features to guide treatment have been controversial. METHODS: Retrospective study with pediatric patients submitted to stereotactic brainstem biopsies between 2008 and 2018. Demographic, clinical, imaging, and surgical characteristics were recorded, as well as the histological diagnosis, complications, and survival. Predictors of survival were evaluated through Cox regression models after multivariate adjustment. RESULTS: Twenty-six patients (mean age of 8.8 ± 4.3 years and 14 female). Diagnosis was reached on 84.6% (95% CI 65.1-95.6%) of the patients. Glioma was diagnosed on 20 cases (11 high-grade and 9 low-grade lesions). There was no association between age and gender and the dichotomized histological diagnosis. Contrast enhancement, diffuse distribution, invasion of adjacent structures, and remote injury were present on 62.5%, 75.0%, 62.5%, and 25.0% of the cases. Hydrocephalus at admission was present on almost half of the patients (46.2%). Only radiological invasion of adjacent structures had a possible association with high-grade lesions (p = 0.057). Surgical trajectory was trans-cerebellar in most of the cases (79.9%). There were no major complications and only two minor/transitory complications. Poorer survival was independently associated with high-grade lesions (HR 32.14, 95% CI 1.40-735.98, p = 0.030) and contrast enhancement at MRI (HR 36.54, 95% CI 1.40-952.26, p = 0.031). CONCLUSIONS: Stereotactic biopsy was safe and allows successful tissue sampling for a definite diagnosis. Poorer survival was independently associated with high-grade and contrast-enhancing lesions.

Biopsia estereotáxica digital y su correlación histopatológica con la biopsia/cirugía radioquirúrgica / Vacuum-assisted stereotactic breast biopsy and histopathological correlation with biopses and radiosurgical surgeries

Introducción La biopsia percutánea con guía estereotáxica digital (bed) ha permitido disminuir el número de cirugías innecesarias y planificar con mejores resultados las biopsias y cirugías radioquirúrgicas. Objetivos El objetivo de este trabajo fue analizar la tasa de subestimación de la punción biopsia percutánea con guía estereotáxica digital y correlacionar la imagen mamográfica con la histopatología. Material y método Se evaluaron 247 pacientes con lesiones mamarias subclínicas diagnosticadas por mamografía y sometidas a una bed (suros) durante el período mayo 2013 a diciembre 2015. Se registró de cada paciente la edad, clasificación de bi-rads, la morfología radiológica de las lesiones, los informes histopatológicos de las bed y de posteriores biopsias y/o cirugías radioquirúrgicas (bp/cxrdq). Se analizaron 237 biopsias (Bp). La edad promedio fue de 52 años. De 237 Bp realizadas, obtuvimos 168 lesiones benignas, 25 lesiones de alto riesgo histológico (larh) y 44 malignas. La sensibilidad de las bed fue del 97,7% y la especificidad del 100%; la tasa de subestimación del método fue del 4% para larh y del 26% para cdis. Las lesiones radiológicas predominantes fueron las microcalcificaciones. Conclusiones La bed ha demostrado ser un excelente método de diagnóstico, con múltiples ventajas respecto de la bprdq, con una buena correlación histopatológica y muy baja tasa de subestimación en larh

Introduction Vacuum-assisted stereotactic breast biopsy (dvab) allowed to reduce the number of unnecessary surgeries and plan with better results biopsies and radiosurgical surgeries. Objectives The aim was to analyze the underestimation rate of dvab and correlate the mammographic image with histopathology. Materials and method 247 patients with subclinical breast lesions diagnosed by mammography and subjected to a dvab (suros) during the period May 2013 - December 2015 were evaluated. The age of each patient, bi-rads classification, radiological morphology of lesions, dvab histopathologic reports and subsequent biopsies and/or radiosurgical surgeries (bp/cxrdq) were registered. 237 biopsies were analyzed. The average age was 52 years. Of 237 Bp realized, we obtained 168 benign lesions (lb), 25 high risk histologically lesions (hrhl) and 44 malignant lesions (lm). The dvab sensitivity and specificity was 97.7% and 100%, respectively. The rate of underestimation of the method was 4% for hrhl and 26% for dcis. Microcalcifications were the predominant radiological lesions. Conclusions The dvab has proved to be an excellent method of diagnosis, with multiple advantages over the BpRDQ, with a good correlation histopathological and very low rate of underestimation in hrhl.

Correlation of (18)F-fluoroethyl tyrosine positron-emission tomography uptake values and histomorphological findings by stereotactic serial biopsy in newly diagnosed brain tumors using a refined software tool.

BACKGROUND: Magnetic resonance imaging (MRI) is the standard neuroimaging method to diagnose neoplastic brain lesions, as well as to perform stereotactic biopsy surgical planning. MRI has the advantage of providing structural anatomical details with high sensitivity, though histological specificity is limited. Although combining MRI with other imaging modalities, such as positron-emission tomography (PET), has proven to increment specificity, exact correlation between PET threshold uptake ratios (URs) and histological diagnosis and grading has not yet been described. OBJECTIVES: The aim of this study was to correlate exactly the histopathological criteria of the biopsy site to its PET uptake value with high spatial resolution (mm(3)), and to analyze the diagnostic value of PET using the amino acid O-(2-[(18)F]fluoroethyl)-l-tyrosine ((18)F-FET) PET in patients with newly diagnosed brain lesions in comparison to histological findings obtained from stereotactic serial biopsy. PATIENTS AND METHODS: A total of 23 adult patients with newly diagnosed brain tumors on MRI were enrolled in this study. Subsequently to diagnoses, all patients underwent a (18)F-FET PET-guided stereotactic biopsy, using an original newly developed software module, which is presented here. Conventional MRI, stereotactic computed tomography series, and (18)F-FET PET images were semiautomatically fused, and hot-spot detection was performed for target planning. UR was determined using the uptake value from the biopsy sites in relation to the contralateral frontal white matter. UR values ≥1.6 were considered positive for glioma. High-grade glioma (HGG) was suspected with URs ≥3.0, while low-grade glioma (LGG) was suspected with URs between 1.6 and 3.0. Stereotactic serial biopsies along the trajectory at multiple sites were performed in millimeter steps, and the FET URs for each site were correlated exactly with a panel of 27 different histopathological markers. Comparisons between FET URs along the biopsy trajectories and the histological diagnoses were made with Pearson product-moment correlation coefficients. Analysis of variance was performed to test for significant differences in maximum UR between different tumor grades. RESULTS: A total of 363 biopsy specimens were taken from 23 patients by stereotactic serial biopsies. Histological examination revealed eight patients (35%) with an LGG: one with a World Health Organization (WHO)-I lesion and seven with a WHO-II lesion. Thirteen (57%) patients revealed an HGG (two with a WHO-III and three with a WHO-IV tumor), and two patients (9%) showed a process that was neither HGG nor LGG (group X or no-grade group). The correlation matrix between histological findings and the UR revealed five strong correlations. Low cell density in tissue samples was found to have a significant negative correlation with the measured cortical uptake rate (r=-0.43, P=0.02), as well as moderate cell density (r=-0.48, P=0.02). Pathological patterns of proliferation (r=0.37, P=0.04), GFAP (r=0.37, P=0.04), and Olig2 (r=0.36, P=0.05) showed a significant positive correlation with cortical URs. Analysis of variance tests showed a significant difference between the LGG and the HGG groups (F=8.27, P<0.002), but no significant differences when differentiating between the X group and the HGG (P=0.2)/LGG (P=0.8) groups, nor between the no-grade group and the WHO-I group. CONCLUSION: (18)F-FET PET is a valuable tool, as it allows the differentiation of HGGs from LGGs. Its use is not limited to preoperative evaluation; it may also refine biopsy targeting and improve tumor delimitation for radiotherapy. Histology is still necessary, and remains the gold standard for definitive diagnosis of brain lesions.

Procedimientos neuroquirúrgicoscerebrales guiados por estereotaxiarealizados en el Hospital Universitario de San Ignacio (HUSI): evolución a corto y mediano plazo / Neurosurgical Brain Estereotactic- Guided Procedures Performed at Hospital Universitario San Ignacio (HUSI): Development in the Short and Medium Term

Objetivo: Describir los resultados postoperatorios de los pacientes a los que se lesrealizaron procedimientos neuroquirúrgicos cerebrales guiados por estereotaxia enel Hospital Universitario de San Ignacio durante el periodo julio del 2009-julio del2011. Materiales y métodos: Se revisaron las historias clínicas de 78 pacientes,sus características clínicas, la localización de las lesiones en las neuroimágenes,el tipo de procedimiento, los resultados funcionales y los desenlaces a corto ymediano plazo. Resultados: 78 pacientes tuvieron procedimientos neuroquirúrgicosguiados por estereotaxia entre julio del 2009 y julio del 2011. El 64,1 % (n = 50)eran hombres. La localización de las lesiones fue en orden de frecuencia: gangliossubtalámicos, lóbulo frontal, lóbulo temporal, tálamo, unión córtico-subcortical, tallocerebral, ubicación frontotemporal, lóbulo occipital, ubicación parieto-occipital ybase del cráneo. Discusión: La implementación de procedimientos neuroquirúrgicosguiados por estereotaxia sigue siendo una de las mejores opciones en el abordaje depatologías cerebrales profundas o de difícil acceso. Tanto en Colombia como en elresto del mundo son procedimientos con una baja tasa de morbilidad y mortalidad.Conclusiones: Independientemente del tipo de procedimiento guiado por estereotaxiala tasa de complicaciones no excede el 5 %, tasas similares a las obtenidas en laliteratura mundial...

Objective: Retrospective description of postoperativeoutcomes of patients who underwentneurosurgical brain stereotactic guided proceduresat the Hospital Universitario San Ignacioduring the period July 2009-July 2011. Materialsand Methods: A review of medical recordsof 78 patients who were taken to neurosurgicalstereotactic guided procedures at the HospitalUniversitario San Ignaci. We reviewed the clinicalcharacteristics of patients, the location of thelesions on neuroimaging, management, type ofprocedure of each patient, functional results andoutcomes in the short and medium term. Results:78 patients who underwent neurosurgical brainstereotactic guided procedures between July2009 to July 2011 at the Hospital UniversitarioSan Ignacio. The 64.1 % (n = 50) were men. Thelocation of the lesions were in order of frequencysub-thalamic ganglia, frontal lobe, temporallobe, thalamus, cortico-subcortical junction, brainstem,fronto-temporal location, occipital lobe,parieto-occipital location, and at the skull’s base.Discussion: Implementing guided stereotacticneurosurgical procedures remains one of the bestoptions in dealing with deep brain pathologies ordifficult access. In both Colombia and the rest ofthe world, these are procedures with low morbidityand mortality. It must, however, developmulticenter studies that allow us to observe thedevelopment of stereotactic neurosurgery in ourcountry, also develop studies with a larger continuityto assess the long-term outcomes. Conclusions:Whatever type of stereotactic guidedprocedure the rate of complications does not exceed5 %, similar rates to those obtained from theglobal literature...

Caracterización de lesiones asociadas a microcalcificaciones BI-RADS 4A, en 11 años de biopsias estereotáxicas / Characterization of lesions associated with microcalcifications BI-RADS 4A over a 11-year period of stereotactic breast biopsies

Substantial advances in breast imaging techniques, especially developments in digital mammography, have led to early detection of breast cancer. It is well-known that microcalcifications are present in approximately 55 percent of nonpalpable breast malignancies and are responsible for the detection of 85-90 percent of cases of ductal carcinoma in situ (DCIS) through mammographic screening. We evaluated the types of associated lesions and the percentage of malignancy in BI-RADS 4A subcategory (low suspicion of malignancy), by performing a database review of stereotactic biopsies of microcalcifications categorized as BI-RADS 4A, between September 1999 and January 2011, which accounted for 21.4 percent of biopsied microcalcifications in a total of 159 women. Histological findings corresponded to benign lesions in 43.5 percent, high-risk lesions in 46.5 percent, and malignant tumors in 10 percent. Concerning the latter (16 biopsies), 81.3 percent were DCIS and 18.7 percent corresponded to infiltrating ductal carcinoma (IDC). The PPV of BI-RADS 4 A category was 13 percent, a value consistent with that described in the literature. Microcalcifications BI-RADS 4A exhibit low suspicion of malignancy, since they mostly correspond to benign lesions (90 percent). Subcategory 4A constitutes an important ancillary diagnostic tool for a more accurate assessment of lesions suspicious for malignancy; therefore, we strongly recommend its use.

El continuo avance en las técnicas de imágenes mamarias, especialmente el desarrollo de la mamografía digital, ha permitido detectar cáncer mamario en etapa precoz. Se sabe que las microcalcificaciones están presentes en el 55 por ciento de los cánceres no palpables y corresponden al 85-90 por ciento de los carcinomas ductales in situ (CDIS) que se detectan con mamografía de screening. Hemos evaluado el tipo de lesiones asociadas y el porcentaje de malignidad de la subcategoría BI-RADS 4A (baja sospecha de malignidad), realizando una revisión de la base de datos de las biopsias estereotáxicas por microcalcificaciones categorizadas BI-RADS 4A entre septiembre 1999 y enero 2011 y que alcanzaron al 21,4 por ciento del total de las microcalcificaciones biopsiadas, en un total de 159 mujeres. Los resultados histológicos correspondieron a lesiones benignas en el 43,5 por ciento, lesiones de alto riesgo en el 46,5 por ciento y malignas en 10 por ciento. De las lesiones malignas (16 biopsias), el 81,3 por ciento fue CDIS y el 18,7 por ciento carcinoma ductal infiltrante (CDI). El VPP de la categoría BI-RADS 4 A fue de 13 por ciento, concordante con la literatura. Las microcalcificaciones BI-RADS 4A son de baja sospecha de malignidad, correspondiendo en su gran mayoría (90 por ciento) a lesiones benignas. La subdivisión en 4 A representa una herramienta que facilita un mejor manejo clínico de las pacientes, por lo que recomendamos su utilización.

Stereotactic biopsy for intracranial lesions: clinical-pathological compatibility in 60 patients / Biopsia estereotáctica para lesões intracranianas: compatibilidade clínico patológica em 60 casos

OBJECTIVE: Image guided stereotactic biopsy (SB) provides cerebral tissue samples for histological analysis from minimal lesions or those that are located in deep regions, being crucial in the elaboration of therapeutic strategies, as well as the prevention of unnecessary neurosurgical interventions. METHOD: Sixty patients with central nervous lesions underwent SB from November 1999 to March 2008. They were followed up to 65 months. Preoperative diagnosis was based on clinical presentation and neuro-radiological features, pathologic diagnosis, clinical outcome. The compatibility of these findings with the pathologic diagnosis was analyzed. RESULTS: Considering diagnosis confirmation when inflammatory hypothesis were made, our accuracy was of 76 percent, with 94 percent of those cases having clinic-pathological correspondence after an average of 65.2 months of follow up. Considering diagnosis confirmation with the preoperative hypothesis of neoplasm, our accuracy was of 69 percent with 90 percent of these cases having clinic-pathological correspondence after an average of 47.3 months of follow-up. Morbidity rate was of 5 percent and mortality was zero. The diagnosis rate was 95 percent. CONCLUSION: Stereotactic biopsy represents a safe and precise method for diagnosis. Anatomic and histopathological analyses have high compatibility with long-term clinical outcome.

OBJETIVO: A biopsia estereotáctica (BE) guiada por imagem propicia amostras de tecido cerebral para análises histológicas, sendo decisiva na estratégia terapêutica e prevenção de intervenções neurocirúrgicas desnecessárias. MÉTODO: 60 pacientes com lesões do sistema nervoso central foram submetidos à biópsia estereotáctica no período de novembro de 1999 a março de 2008. Foram analisados a acurácia do método, a capacidade de confirmar o diagnóstico clínico pré-operatório e o comportamento evolutivo com sua compatibilidade com o diagnóstico patológico. RESULTADOS: As três lesões mais freqüentes foram: neoplasias neuroepiteliais, processos inflamatórios e infecções. Considerando a confirmação diagnóstica quando pensava-se em lesão inflamatória, nossa acurácia foi 76 por cento, com 94 por cento destes casos tendo compatibilidade clínico patológica após média de 65,2 meses de acompanhamento. Considerando a confirmação diagnóstica com a hipótese pré-operatória de lesão neoplásica, nossa acurácia foi 69 por cento, com 90 por cento destes casos tendo compatibilidade clínico-patológica após média de 47,3 meses de acompanhamento. O índice de morbidade foi 5 por cento. A mortalidade foi nula e o índice de diagnóstico foi 95 por cento. CONCLUSÃO: A biopsia estereotáctica é um método seguro e preciso para o diagnóstico. O exame anátomo-patológico possui alta compatibilidade com a evolução clínica dos doentes a longo prazo.

Brainstem biopsies in adults: Review of 80 consecutive cases / Biópsia estereotáxica das lesões do tronco cerebral. Estudo de 80 casos consecutivos

Objective: To retrospectively review the morbidity and mortality rates associated with stereotactic brainstem lesion biopsy, the success rate and the impact on treatment. Material and methods: Eighty consecutive stereotactic biopsies and literature review were performed to analyze clinical, radiographic and histopathological data. Results: Stereotactic biopsy of brainstem lesions conducted to the diagnosis in 96.3%. One death (1.3% of cases) occurred and 10% morbidity was associated with the procedure. Pathology showed that 65% of the adult brainstem intrinsic lesions were gliomas, 11.3% were metastasis, 8.7% were lymphomas and the remaining tumoral lesions were ganglioglioma, ependymoma and craniopharyngeoma. Non-tumoral lesions were the diagnosis in 11 cases. Conclusion: Empiric treatment of adult brainstem lesions is not prudent, because a wide spectrum of pathologies occur in this location. Stereotactic biopsy is a safe and effective method for determining the diagnostic of these lesions.

Objetivo: Analisar retrospectivamente as taxas de morbidade e mortalidade associadas ao procedimento de biópsia estereotáxica das lesões do tronco encefálico, assim como sua taxa de sucesso e impacto no tratamento. Material e métodos: Foram analisados retrospectivamente 80 casos consecutivos de biópsia estereotáxica de lesões do tronco encefálico e confrontados seus dados clínicos, imagiológicos e histopatológicos com dados da literatura atual. Resultados: A biópsia estereotáxica das lesões do tronco encefálico obteve diagnóstico em 96,3% dos casos. A taxa de mortalidade foi de 1,3% e de morbidade de 10%. Estudo histopatológico evidenciou que 65% das lesões intrínsecas do tronco encefálico do adulto eram gliomas, 11,3% eram metástases, 8,7%, linfomas, e o restante das lesões tumorais eram gangliogliomas, ependimomas e craniofaringeomas. Foram diagnosticadas lesões não tumorais em 11 casos. Conclusão: Tratamento empírico das lesões do tronco encefálico do adulto não é prudente em virtude do amplo espectro de patologias que podem acometer esta região. Concluímos que a biópsia estereotáxica é método seguro e efetivo para determinar o diagnóstico de tais lesões.

Estudo retrospectivo e analítico de biópsias estereotácticas / Retrospective study of stereotactic brain biopsies

Fundamento: A biópsia estereotáctica tem sido considerada técnica simples e sem complicações e com resultados satisfatórios para o diagnóstico. Neste estudo ficou evidente que nem sempre o procedimento é simples e pode apresentar riscos. Métodos: Foram analisados procedimentos (n=78) para biópsia estereotáctica de novembro de 2000 a setembro de 2007. As biópsias foram diagnósticas em 85,7% e não diagnósticas em 4%. Os procedimentos foram realizados em centro cirúrgico próximo à radiologia e à sala de patologia. Foi usado equipamento do tipo arco-alvo-centrado compatível com coordenadas cartesianas. Os fiduciais usados foram adequados somente para o equipamento de TC. A cânula de biópsia foi do tipo Nashold e as coordenadas foram calculadas no tomógrafo com programa computadorizado. Resultados: Pré-operatoriamente, observaram-se déficits motores e visuais em 35%, convulsões em 38% e alterações do nível de consciência em 27%. Foram incluídos nas biópsias pacientes com lesões expansivas intracranianas e as indefinidas. Foram excluídos os casos com discrasia sanguínea, tumores vasculares, intraventriculares e doença de Creutzfeldt-Jakob. As lesões expansivas predominaram no nível supratentorial e os homens foram mais afetados do que as mulheres: 64% e 36% respectivamente. O mais jovem tinha 16 anos e o mais velho 74. A lesão expansiva predominante foi o glioblastoma multiforme. Entre os diagnósticos da TC 1/3 não correspondeu à biópsia. Não houve morbidade e/ou mortalidade. Conclusão: O procedimento da biópsia estereotáctica não é isenta de risco, assim como de complicações. Em 1/3 dos casos o diagnóstico neuro-radiológico foi diferente do resultado da biópsia dificultando a conduta cirúrgica. O glioma predominante foi do tipo glioblastoma multiforme supratentorial em faixa etária mais alta e glioma de baixo grau nos mais jovens.

Background: Stereotactic biopsy has been considered simple and safe. In this paper it is shown that the stereotactic procedure is not always without risk. Methods: Procedures (n=78) for stereotactic biopsy were analysed from november 2000 to september 2007. Diagnosis was accurate in 85,7% and misdiagnosis was 4%. The isocentric stereotactic arc-centered system type was used with cartesian system of coordinates. Fiducials were adapted only for CT scanner. Biopsy probe Nashold was used. The coordinates were made within the tomographic machine. Results: The patients presented lesions causing motor déficits and visual disturbances in 35%, convulsions in 38%, and conscience level disturbances in 27%. Patients with tumours and undefined lesions were chosen. Patients with blood dyscrasia, vascular and intraventricular tumors, and Creutzfeldt-Jakob disease were excluded. The tumours were mainly supratentorial and men were more affected than women. The younger patient was 16 and the olderst 74 years old. Glioblastoma was the more frequent glioma. Among the cases, 1/3 diagnosed by neuroradiologists was different in relation to the pahological findings. No morbimortality was registered. Conclusions: Stereotactic biopsies are not always safe and with no risks. The neuroradiologic diagnosis were different in 1/3 of the cases in comparison to the pathological findings. The predominant glioma was the glioblastoma type for the older and low grade gliomas for the younger subjects.

Biópsia estereotáxica no diagnóstico de tumores cerebrais e lesões não-neoplásicas: indicações, acurácia e dificuldades diagnósticas: [revisão] / Stereotactic biopsy in the diagnosis of brain tumors and non-neoplastic lesions: prescription, accuracy and diagnostic difficulties: [revision]

Objetivo: A biópsia estereotáxica (BE) é um procedimento valioso e seguro para o diagnóstico das lesões expansivas intracranianas. Essa revisão analisa a literatura sobre a importância e a acurácia da BE no diagnóstico de tumores cerebrais e de lesões não-neoplásicas. Resultados: Foram analisados os principais achados anatomopatológicos de cerca de 11.500 BEs provenientes de grandes séries publicadas entre 1980 e 2008. Um diagnóstico histopatológico foi possível em 80% a 99% dos pacientes. As lesões mais freqüentemente encontradas foram neoplasias (64% a 86,4%), principalmente gliomas (61,7% a 71%), e processos não-neoplásicos (4% a 32%). Amostras nas quais não foi possível fazer um diagnóstico foram identificadas em 3,4% a 18,7% dos casos. As principais lesões não-neoplásicas diagnosticadasforam infecções (8% a 15%) e infartos (0,6% a 6%). As causas predominantes para a obtenção de amostras não-diagnósticas foram pequeno tamanho da amostra, lesão de dimensões pequenas, lesão localizada em estruturas cerebrais profundas e cálculo errôneo do alvo resultando em erro na obtenção da amostra. A utilização do esfregaço peroperatório e/ou do corte de congelação permitiu rápido diagnóstico com elevado grau de acurácia, além de ter melhorado a qualidade dos fragmentos coletados durante a realização da BE. Conclusão: A BE é um procedimento seguro e eficaz, o que a torna indicada na abordagem das lesões expansivas intracranianas nas quais não são recomendáveis craniotomia e ressecção ampla da lesão. Possui acurácia elevada, desde que realizada por profissionais habilitados e examinada por patologista ou neuropatologista experiente. A possibilidade de confecção de esfregaçoe/ou corte de congelação aumenta o grau de acerto do diagnóstico da BE.

Objective: Stereotactic biopsy (SB) is an invaluable and safe procedure in the diagnosis of intracranial expanding lesions. This review analyses the literature as to the relevance and accuracy of SB in the diagnosis of brain tumors and non-neoplastic lesions. Results: The main anatomicopathologic findings of approximately 11,500 stereotactic brain biopsies from large series published between 1980 and 2008 were reviewed. A histopathological diagnosis was reached in 80% to 99% of the patients. The most frequently found lesions were neoplasms (64% to 86.4%), especially gliomas (61.7% to 71%), and non-neoplastic lesions (4% to 32%). The diagnosis was non-conclusive in 3.4% to 18.7% of the samples. The most common non-neoplastic lesions were infections (8% to 15%) and infarcts (0.6% to 6%). Non-diagnostic specimens were obtained due to smallsample size, small lesions, lesions located in deep brain structures and inaccurate tissue targeting resultingin sampling error. The use of intraoperative smear and/or frozen section allowed a rapid diagnosis with high level of accuracy as well as it improved the quality of specimens collected during SB procedure. Conclusions: SB is a safe and effective procedure for evaluating intracranial expanding lesions when craniotomy and an open surgical resection are not recommended. It has high accuracy as long as it is performed by experiencedand skilled professionals and examined by experienced pathologists or neuropathologists. The use of smear and/or frozen section increases the diagnostic yield of SB.

La biopsia estereotáctica en el diagnóstico de las lesiones cerebrales focales en sida / Stereotactic brain biopsy in the diagnosis of focal brain lesions in AIDS

Las lesiones cerebrales focales constituyen una complicación frecuente en los pacientes con infección por el virus de la inmunodeficiencia humana (HIV) y síndrome de inmunodeficiencia adquirida (sida). Durante el período comprendido entre enero de 1999 y mayo de 2007 se realizaron un total de 83 biopsias en pacientes con sida y lesiones cerebrales. Se incluyeron aquellos pacientes que no hubiesen respondido al algoritmo habitual de enfoque diagnóstico-terapéutico de estas lesiones. Todas las muestras obtenidas fueron sometidas a evaluación intraoperatoria para asegurar la obtención de material patológico y posterior análisis histopatológico y exámenes microbiológicos. De los 41 pacientes con lesiones cerebrales múltiples, 62 tenían localización supratentorial, en 4 eran infratentoriales y 17 mostraron ambas localizaciones. Cincuenta y un lesiones seleccionadas como blanco estereotáctico tuvieron refuerzo periférico del contraste. Se obtuvo material histopatológico en el 100% de los procedimientos. El diagnóstico más frecuente fue el de leucoencefalopatía multifocal progresiva (LEMP) con 24 casos (29%), seguido del linfoma primario del sistema nervioso central (LPSNC) con 19 diagnósticos (23%) y de toxoplasmosis en 13 pacientes (15.7%). Se comprobó una relación significativa entre los diagnósticos histopatológicos y la localización de las lesiones y entre los diagnósticos histopatológicos y el comportamiento de las imágenes luego de la administración de la sustancia de contraste. El rédito diagnóstico alcanzó el 90.3% (75 biopsias). La morbiletalidad en esta serie fue de 2.4%. La biopsia cerebral estereotáctica permitió alcanzar el diagnóstico etiológico y adecuar el enfoque terapéutico en la mayoría de los pacientes de esta serie.

Focal brain lesions are frequent complications among HIV/AIDS patients. Between January 1999 and May 2007, 83 procedures of stereotactic brain biopsies in HIV/AIDS patients with focal cerebral lesions were carried out. The inclusion criteria were lack of response to current diagnostic and therapeutic guidelines for brain lesions. All the samples underwent microscopic evaluation during surgery to assert valid material and delayed histopathological and microbiological examination. Forty one patient images demonstrated multiple brain lesions. Sixty two cases had supratentorial localization, 4 lesions were located beneath the tentorium and 17 showed both settings. Fifty one lesions presented peripheral enhancement after contrast computed tomography (CT) or magnetic resonance imaging (MRI). A 100% of useful samples recovery was achieved. Progressive multifocal leucoencephalopathy (PML) was the most frequent diagnosis (29%), followed by primary central nervous system lymphoma (PCNSL) (23%), and toxoplasmosis (15.7%). Statistically significant association was observed between histopathological diagnosis and lesion location and between those and peripheral ring enhancement images. The positive diagnostic rate of the invasive procedure was 90.3%. The morbidity/mortality rate was 2.4% in this series. In conclusion, the stereotactic brain biopsy ordered early during the patient’s evolution showed a good performance in order to achieve a prompt and accurate diagnosis and to guide the therapeutic scheme in these AIDS patients with focal brain lesions.

Linfoma primario del sistema nervioso central en pacientes inmunocompetentes / Primary central nervous system lymphoma in immunocompetent patients

El linfoma primario del sistema nervioso central ha sido informado con frecuencia en pacientes que padecen síndromes de inmuno deficiencia. Sin embargo ésta no es una condición necesaria para su presentación, dado que existen informes de la enfermedad en sujetos inmunológicamente competentes. En el presente trabajo se analizaron en forma retrospectiva, los expedientes de 22 pacientes inmunocompetentes con diagnóstico confirmado de linfoma primario encefálico, se revisó la literatura mundial, con el fin de analizar objetivamente las manifestaciones clínicas, comportamiento radiológico, aspecto histopatológico, dificul tades diagnósticas y terapéuticas, así como las consideraciones pro nósticas. El promedio de edad fue de 65 años y con una relación equitativa hombre/mujer. El tiempo de evolución del cuadro clínico fue de 80.4 días y estuvo dominado por cefalea y déficit neurológico focal. En cuatro pacientes se encontraron lesiones múltiples, mientras que en el resto se trataba de lesiones únicas con localización predominante en la región periventricular de los hemisferios cerebrales. Todos los pacientes fueron manejados inicialmente con esteroides y sometidos a toma de biopsia por estereotaxia. La variedad histológica más frecuente fue la de células grandes difusas y la totalidad de los casos reaccionaron positivamente a antígenos de células B en la inmunohistoquímica. Los 22 pacientes fueron tratados con radio terapia y 10 de ellos además con quimioterapia con metotrexato. La supervivencia promedio fue de 11 meses en los pacientes radiados y de 36 meses en los que se agregó quimioterapia.

Primary central nervous system lymphoma has been traditionally described in patients with immunodeficiency syndromes; however, there is an increasing number of immunocompetent patients with this type of tumor that have been reported recently. In this paper we have retrospectively analyzed 22 immunocompetent patients with a confirmed diagnosis of primary lymphoma of the brain. The mean age in this group was 65 years with a similar male/female ratio. The time of evolution of the clinical course was 80.4 days and it was mainly characterized by headache and focal neurological deficit. In four patients multiple lesions were observed, while the remaining presented single lesions mainly located in the periventricular area of the cerebral hemispheres. All patients were initially administered steroids and a stereotactic biopsy was performed. The majority of tumors were histologically classified as diffuse large cells and all of them showed a positive reaction to B cells antigens on immunohistochemistry. All patients were treated with radiotherapy and in 10 of them, chemotherapy with methotrexate was also indicated. The mean survival rate was 11 months among patients treated with radiotherapy alone and increased to 36 months when chemotherapy was added.