Surgical Management of Craniovertebral Junction Schwannomas: A Systematic Review.

BACKGROUND: Craniovertebral junction (CVJ) schwannomas are rare, with surgery and stereotactic radiosurgery (SRS) being effective yet challenging options. We systematically reviewed the literature on CVJ schwannomas. METHODS: PubMed, Scopus, Web-of-Science, and Cochrane were searched following the PRISMA statement to include studies reporting CVJ schwannomas. Clinical features, management, and outcomes were analyzed. RESULTS: We collected 353 patients from 101 included articles. Presenting symptoms were mostly neck pain (30.3%) and headache (26.3%), with most cranial neuropathies involving the XII (31.2%) and X (24.4%) nerves. Most tumors originated from C2 (30.9%) and XII (29.4%) nerves, being extracranial (45.1%) and intradural-extradural (44.2%). Erosion of C1-C2 vertebrae (37.1%), the hypoglossal canal (28.3%), and/or jugular foramen (20.1%) were noted. All tumors were operated, preferably with the retrosigmoid approach (36.5%), with the far-lateral approach (29.7%) or with the posterior approach and cervical laminectomy (26.9%), far-lateral approaches (14.2%), or suboccipital craniotomy with concurrent cervical laminectomy (14.2%). Complete tumor resection was obtained most frequently (61.5%). Adjuvant post-surgery stereotactic radiosurgery was delivered in 5.9% patients. Median follow-up was 27 months (range, 12-252). Symptom improvement was noted in 88.1% of cases, and cranial neuropathies showed improvement in 10.2%. Post-surgical complications occurred in 83 patients (23.5%), mostly dysphagia (7.4%), new cranial neuropathies (6.2%), and cerebrospinal fluid leak (5.9%). A total of 16 patients (4.5%) had tumor recurrence and 7 died (2%), with median overall survival of 2.7 months (range, 0.1-252). CONCLUSIONS: Microsurgical resection is safe and effective for CVJ schwannomas. Data on SRS efficacy and indications are still lacking, and its role deserves further evaluation.

Early-onset adverse events after stereotactic radiosurgery for jugular foramen schwannoma: a mid-term follow-up single-center review of 46 cases.

BACKGROUND: Recently, stereotacitc radiosurgery (SRS) has been in the spotlight as an alternative therapeutic option for jugular foramen schwannomas (JFS). While most reported studies focus on the long-term efficacy and safety issues of SRS, none describe the early-onset adverse events (eAEs). We aimed to investigate the incidence, clinical characteristics, and mid-term outcomes of eAEs occurring within six months after SRS for JFS. METHODS: In this retrospective review, patients who underwent at least six months of follow-up were included among all patients with JFS who have performed SRS at our institution between July 2008 and November 2019. And eAEs were defined as a newly developed neurological deficit or aggravation of pre-existing symptoms during the first six months after SRS. RESULTS: Forty-six patients were included in the analysis. The median follow-up period was 50 months (range 9-136). The overall tumor control rate was 91.3%, and the actuarial 3-, 5-, and 10-year progression-free survival rates were 97.8%, 93.8%, and 76.9%, respectively. Of the 46 patients, 16 had eAEs, and the median time to onset of eAEs was one month (range 1-6 months), and the predominant symptoms were lower cranial nerve dysfunctions. Thirteen of 16 patients showed improved eAE symptoms during the follow-up period, and the median resolution time was six months (range 1-52). In 11 (68.8%) of 16 patients with eAEs, transient expansions were observed with a mean of 3.6 months after the onset of eAEs, and the mean difference between the initial tumor volume and the transient expansion volume was more prominent in the patients with eAEs (3.2 cm3 vs. 1.0 cm3; p = 0.057). In univariate analysis, dumbbell-shaped tumors (OR 10.56; p = 0.004) and initial tumor volume (OR 1.32; p = 0.033) were significantly associated with the occurrence of eAEs. CONCLUSIONS: Although acute adverse events after SRS for JFS are not rare, these acute effects were not permanent and mostly improved with the steroid treatment. Dumbell-shaped and large-volume tumors are significant predictive factors for the occurrence of eAEs. And the transient expansion also seems to be closely related to eAEs. Therefore, clinicians need to be more cautious when treating these patients and closely monitor the occurrence of eAEs.

Current Understanding of Neurofibromatosis Type 1, 2, and Schwannomatosis.

Neurofibromatosis (NF) is a neurocutaneous syndrome characterized by the development of tumors of the central or peripheral nervous system including the brain, spinal cord, organs, skin, and bones. There are three types of NF: NF1 accounting for 96% of all cases, NF2 in 3%, and schwannomatosis (SWN) in <1%. The NF1 gene is located on chromosome 17q11.2, which encodes for a tumor suppressor protein, neurofibromin, that functions as a negative regulator of Ras/MAPK and PI3K/mTOR signaling pathways. The NF2 gene is identified on chromosome 22q12, which encodes for merlin, a tumor suppressor protein related to ezrin-radixin-moesin that modulates the activity of PI3K/AKT, Raf/MEK/ERK, and mTOR signaling pathways. In contrast, molecular insights on the different forms of SWN remain unclear. Inactivating mutations in the tumor suppressor genes SMARCB1 and LZTR1 are considered responsible for a majority of cases. Recently, treatment strategies to target specific genetic or molecular events involved in their tumorigenesis are developed. This study discusses molecular pathways and related targeted therapies for NF1, NF2, and SWN and reviews recent clinical trials which involve NF patients.

Natural history of peripheral nerve schwannomas.

BACKGROUND: Little information about the natural history of peripheral nerve schwannomas exists in the literature. The aim of this study was to determine the natural history of those tumors both in sporadic and schwannomatosis cases to determine their growth rates and patterns. METHODS: In 44 patients from 3 surgical centers, hospital charts, follow-up records, and imaging studies were reviewed. Of these patients, 7 had sporadic schwannomatosis. Histological diagnosis was obtained in 37 patients (84%). Tumor growth rates were determined by calculating the absolute and relative growth rates. RESULTS: On the 47 tumors analyzed, the median tumor size at diagnosis was 1.8 cm3, and the majority of tumors were located in the lower limb (62%). The absolute growth rate ranged from - 1.13 to 23.17 cm3/year (mean, 1.69 cm3/year). Relative annual growth rates ranged from - 9 to 166%/year (mean, 33.9%/year). There was no clear correlation between initial tumor size, age at diagnosis, and tumor growth rate. Six patients (13%) harbored "fast-growing" tumors (absolute growth rate > 2 cm3/year and relative growth rate > 35%/year) while 19% of tumors demonstrate no growth or negative growth. In schwannomatosis patients, each tumor displayed a distinct growth pattern. CONCLUSION: This study confirms the slow-growing nature of most, but not all, peripheral nerve schwannomas. Additional studies are mandatory to explore the environmental factors influencing growth in sporadic cases and the precise growth patterns in schwannomatosis cases to detect the rare cases of malignant transformation and pave the way to the evaluation of future clinical trials.

Radiation risk of central nervous system tumors in the Life Span Study of atomic bomb survivors, 1958-2009.

Radiation exposure is among the few factors known to be associated with risk of central nervous system (CNS) tumors. However, the patterns of radiation risk by histological type, sex or age are unclear. We evaluated radiation risks of first primary glioma, meningioma, schwannoma, and other or not otherwise specified (other/NOS) tumors in the Life Span Study cohort of atomic bomb survivors. Cases diagnosed between 1958 and 2009 were ascertained through population-based cancer registries in Hiroshima and Nagasaki. To estimate excess relative risk per Gy (ERR/Gy), we fit rate models using Poisson regression methods. There were 285 CNS tumors (67 gliomas, 107 meningiomas, 49 schwannomas, and 64 other/NOS tumors) among 105,444 individuals with radiation dose estimates to the brain contributing 3.1 million person-years of observation. Based on a simple linear model without effect modification, ERR/Gy was 1.67 (95% confidence interval, CI: 0.12 to 5.26) for glioma, 1.82 (95% CI: 0.51 to 4.30) for meningioma, 1.45 (95% CI: - 0.01 to 4.97) for schwannoma, and 1.40 (95% CI: 0.61 to 2.57) for all CNS tumors as a group. For each tumor type, the dose-response was consistent with linearity and appeared to be stronger among males than among females, particularly for meningioma (P = 0.045). There was also evidence that the ERR/Gy for schwannoma decreased with attained age (P = 0.002). More than 60 years after the bombings, radiation risks for CNS tumors continue to be elevated. Further follow-up is necessary to characterize the lifetime risks of specific CNS tumors following radiation exposure.

What's new in nerve sheath tumors.

Peripheral nerve sheath tumors are commonly encountered and frequently pose challenges to the pathologist and the clinician. This review discusses the wide range of entities with an emphasis on new discoveries in the past decade. Clinical, histologic, immunohistochemical, and pathogenetic findings are discussed with an emphasis on clinical implications and differential diagnosis.

Neurofibromatosis tipos 1 y 2 / Neurofibromatosis type 1 and 2

La neurofibromatosis (NF) comprende un grupo de enfermedades genéticas de herencia autosómica dominante, que se clasifican de la siguiente manera: neurofibromatosis tipo 1 (NF1), neurofibromatosis tipo 2 (NF2) y schwannomatosis (también conocida como neurofibromatosis tipo 3). Esta última es una enfermedad muy infrecuente, con una prevalencia aproximada de 1/126 000 personas, por lo que solo profundizaremos las dos primeras. La NF1, también conocida como la enfermedad de Von Recklinghausen, es la más frecuente de las tres y afecta principalmente la piel y el sistema nervioso periférico. Se caracteriza por la presencia de máculas "café con leche", pecas axilares o inguinales, nódulos de Lisch (hamartomas en el iris) y neurofibromas (tumores de la vaina de nervios periféricos). Otras manifestaciones menos frecuentes, aunque de mayor gravedad, incluyen gliomas del nervio óptico, meningiomas, neurofibromas malignos, escoliosis y displasia de la tibia. Su diagnóstico se suele realizar al nacimiento o durante los primeros años de vida, y se estima que un 50% de quienes la padecen presenta dificultades cognitivas. No hay datos concluyentes sobre la mortalidad en los pacientes con NF1, aunque se sabe que la expectativa de vida es menor que en la población general. La NF2 tiene una prevalencia considerablemente menor que la NF1 y su inicio es más tardío, afectando principalmente a adultos jóvenes. La presentación clínica típica se caracteriza por acúfenos, hipoacusia y ataxia en contexto de la presencia de schwannomas vestibulares bilaterales. Otros hallazgos menos frecuentes incluyen schwannomas de nervios periféricos, meningiomas, ependimomas o astrocitomas. La esperanza de vida es de unos 36 años, con una supervivencia media desde el momento del diagnóstico de 15 años. (AU)

Neurofibromatosis (NF) includes a group of genetic diseases with an autosomal-dominant inheritance pattern, and they are classified as follows: Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and Schwannomatosis (also known as neurofibromatosis type 3). This last one is a very rare disease, with an approximate prevalence of 1/126000, so we will only deepen in the first two. NF1, also known as von Recklinghausen disease, is the most frequent, and mainly affects the skin and peripheral nervous system. Its typical manifestations are the presence of café-au-lait macules, axillary or inguinal freckles, Lisch nodules (hamartomas in the iris) and neurofibromas (peripheral nerve sheath tumors). Less frequent manifestations, although more serious, include optic nerve gliomas, meningiomas, malignant neurofibromas, scoliosis and tibial dysplasia. The diagnosis is usually made at birth or during the first years of life, and approximately 50% of patients present cognitive difficulties. There is no conclusive data on mortality in patients with NF1, although it is known that life expectancy is lower than in general population. NF2 has a considerably lower prevalence than NF1, and its onset is later in life, mainly affecting young adults. Its typical clinical presentation is characterized by tinnitus, hearing loss and ataxia in the context in the presence of bilateral vestibular schwannomas. Less frequent findings include peripheral nerve schwannomas, meningiomas, ependymomas or astrocytomas. Life expectancy is about 36 years old, with a median survival from the moment of diagnosis of 15 years. (AU)

Peripheral Nerve Schwannomas: A Literature Review

Introduction Schwannomas are benign tumors originating from the cells, which wrap around axons that are usually encapsulated and solitary. These tumors usually lead to little or no symptomatology. They are usually the most common peripheral nerve tumors in adults, with their highest incidence between the third and fifth decades of life. Objective To perform a review about schwannoma of the peripheral nerves, presenting its definition, epidemiology, diagnosis, symptomatology and treatment. Methodology This is a descriptive work, based on a review of articles available in the PubMed database with the descriptors schwannoma and peripheral nerves. Results and Discussion Only papers published between 1981 and 2019, describing studies in humans, and that were available as full articles were selected. A total of 391 articles were included; after reading the titles, we noted that 67 articles fit the topic of the present study. Among the articles selected for reading, 33 fit the objectives of the present work, and were considered for the writing of the present article. Conclusion Schwannomas are benign myelin sheath tumors that develop with local symptomatology or asymptomatic and present a good surgical prognosis with generally reduced rates of surgical complications.

Environmental risk factors of primary brain tumors: A review.

Adult primary tumors of the central nervous system are rare, but the incidence is increased in some European countries. Several environmental exposures have been investigated as potential risk factors, but for most, scientific evidence is still lacking. Here we review studies of environmental factors potentially involved in the carcinogenesis of brain tumors: the potential association between primary central nervous system tumors and ionizing radiation, some toxic agents (N-nitroso compounds, pesticides), air pollution, and radiofrequency electromagnetic waves. Brain-ionizing irradiation, especially during childhood, constitutes a well-established risk factor for brain tumors. Exposure to environmental toxins has been poorly explored and data give inconsistent clues about N-nitroso compounds or pesticides as risk factors of brain tumors even for prenatal exposure. For out-door pollution and risk of brain tumour, results of large prospective studies are contradictory. The effect of mobile phones on the risk of developing brain tumors has not been established for glioma and meningioma in adults, but the link with acoustic neurinoma is becoming robust. The effect of mobile phones has still not been explored in children.

Schwannoma Formation in Childhood Cancer Survivors Exposed to Total Body Irradiation: Case Series.

Childhood cancer survivors are at risk for ongoing health risks related to their initial treatment. One potential long-term complication following radiation is the development of secondary tumors, including peripheral nerve tumors, such as schwannomas. We present three adolescent and young adult (AYA)-aged survivors of pediatric cancer (22-40 years), followed in our AYA survivorship clinic. Each was found to have a schwannoma many years following total body irradiation for a childhood primary malignancy. We highlight a late effect of low-dose total body irradiation as well as the importance of long-term monitoring in this population.

From process to progress-2017 International Conference on Neurofibromatosis 1, Neurofibromatosis 2 and Schwannomatosis.

The neurofibromatoses are inherited, tumor suppressor disorders that are characterized by multiple, benign peripheral nerve sheath tumors and other nervous system tumors. Each disease is associated with a distinct genetic mutation and with a different pathogenesis and clinical course. Neurofibromatosis 1 (NF1) is common and epitomized by multiple neurofibromas with widespread complications. NF2 and schwannomatosis are rare diseases that are typified by multiple schwannomas that are particularly painful in people with schwannomatosis. Since 1985, the Children's Tumor Foundation (formerly the National Neurofibromatosis Foundation) has hosted an international Neurofibromatosis Conference, bringing together international participants who are focused on NF research and clinical care. The 2017 Conference, held in Washington, DC, was among the largest gatherings of NF researchers to date and included presentations from clinicians and basic scientists, highlighting new data regarding the molecular and cellular mechanisms underlying each of these diseases as well as results from clinical studies and clinical trials. This article summarizes the findings presented at the meeting and represents the current state-of-the art for NF research.

Multiple cranial nerve schwannomas and meningiomas as a hallmark sign of neurofibromatosis type 2 in a child.

Halefoglu AM. Multiple cranial nerve schwannomas and meningiomas as a hallmark sign of neurofibromatosis type 2 in a child. Turk J Pediatr 2018; 60: 107-110. Neurofibromatosis type 2 is a rarely encountered autosomal dominant disorder manifesting with typical radiological findings. These patients have a predilection for development of benign tumors in the central nervous system. Although the presenting symptom is most commonly hearing loss due to acoustic schwannomas, symptoms emanating from other cranial tumors are not uncommon. Herein, we described a 16-year-old male patient presented with multiple meningiomas and cranial nerve schwannomas revealed by magnetic resonance imaging. He fulfilled the diagnostic criteria of neurofibromatosis type 2 and underwent treatment. We emphasized the role of radiology in the early diagnosis of this inherited disorder in order to provide a better prognosis.

2016 Children's Tumor Foundation conference on neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis.

Organized and hosted by the Children's Tumor Foundation (CTF), the Neurofibromatosis (NF) conference is the premier annual gathering for clinicians and researchers interested in neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis (SWN). The 2016 edition constituted a blend of clinical and basic aspects of NF research that helped in clarifying different advances in the field. The incorporation of next generation sequencing is changing the way genetic diagnostics is performed for NF and related disorders, providing solutions to problems like genetic heterogeneity, overlapping clinical manifestations, or the presence of mosaicism. The transformation from plexiform neurofibroma (PNF) to malignant peripheral nerve sheath tumor (MPNST) is being clarified, along with new management and treatments for benign and premalignant tumors. Promising new cellular and in vivo models for understanding the musculoskeletal abnormalities in NF1, the development of NF2 or SWN associated schwannomas, and clarifying the cells that give rise to NF1-associated optic pathway glioma were presented. The interaction of neurofibromin and SPRED1 was described comprehensively, providing functional insight that will help in the interpretation of pathogenicity of certain missense variants identified in NF1 and Legius syndrome patients. Novel promising imaging techniques are being developed, as well as new integrative and holistic management models for patients that take into account psychological, social, and biological factors. Importantly, new therapeutic approaches for schwannomas, meningiomas, ependymomas, PNF, and MPNST are being pursued. This report highlights the major advances that were presented at the 2016 CTF NF conference.

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism.

BACKGROUND: We report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed. CASE PRESENTATION: A 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8 × 5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection. CONCLUSION: A clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.

Schwannoma en la lengua: tumoración insólita en la infancia / Schwannoma of the tongue: rare tumor in infancy

El schwannoma o neurilemmoma de la lengua es un tumor benigno muy poco frecuente en las edades pediátricas. Varón, de 8 años, que presenta una tumoración situada en la punta de la lengua, asintomática, de crecimiento progresivo durante 6 meses. La tumoración es dura, de 1,5 cm de longitud, de aspecto grisáceo y sin síntomas acompañantes. Tras una exploración y una impresión clínica de tumoración benigna, se realiza una resección completa de la masa, no observándose nuevo crecimiento en los más de 5 años de evolución ni aparición de nuevos síntomas (AU)

The schwannoma or neurilemmoma of the tongue is a benign tumor which is very rare in the pediatric age. Eight year old male, with a tumor located at the tip of the tongue, asymptomatic, that has been growing progressively for 6 months. The tumor is hard, 1.5 cm in length, gray, without accompanying symptoms. After an examination and clinical impression of a benign tumor, a complete resection of the mass was performed, with no new growth observed in more than 5 years of evolution or the appearance of new symptoms (AU)

Radiation-Induced Malignant Peripheral Nerve Sheath Tumors: A Systematic Review.

OBJECTIVE: Radiation-induced malignant peripheral nerve sheath tumors (MPNSTs) are an uncommon late risk of irradiation. We conducted the largest systematic review to date of individual patient data for patients with these tumors. METHODS: We conducted a systematic search using the PubMed database, and compiled a systematic literature review. We used Kaplan-Meier analysis and a log-rank test to estimate survival. RESULTS: We analyzed 65 radiation-induced and 26 radiation-associated MPNSTs in patients with neurofibromatosis. The mean ages of onset for primary lesions of the 2 types were 31.7 ± 18.2 and 17.1 ± 12.4 years, respectively (P = 0.0008). The latency periods between radiotherapy and onset of the 2 types of MPNSTs were 13.5 ± 7.8 and 11.8 ± 7.5 years, respectively (P = 0.3101). The median overall survival and 5-year survival were 11 months (6.8%) and 23 months (5.8%), respectively (P = 0.2168). Negative surgical margin and patient sex were variables retained for the prognosis of radiation-induced and radiation-associated MPNSTs. CONCLUSIONS: The prognosis of radiation-induced and radiation-associated MPNST was worse than that reported for de novo MPNSTs. Surgical complete resection is the mainstay for treatment of radiation-induced and radiation-associated MPNSTs. The risk of incidence of secondary MPNSTs in patients treated with radiotherapy warrants longer follow-up periods.

Radiation-Induced Schwannomas and Neurofibromas: A Systematic Review.

OBJECTIVE: Radiation-induced benign peripheral nerve sheath tumors are uncommon late complications of irradiation. We conducted the largest systematic review of individual patient data. METHODS: We performed a systematic search of PubMed databases and compiled a comprehensive literature review. Kaplan-Meier analysis was used to investigate survival, and statistical significance was assessed with a log-rank test. RESULTS: We analyzed 40 cases of radiation-induced benign peripheral nerve sheath tumors. The histologic distributions were 28 schwannomas, 11 neurofibromas, and 1 ganglioneuroma. The average age of radiation exposure for development of primary lesions was 14.9 ± 15.5 years, and the latency period between radiotherapy to the onset of secondary tumors was 24.5 ± 12.7 years. The average irradiation dose delivered was 26.3 ± 20.3 Gy. The median overall survival for all cases was not reached (95% confidence interval, 22-not reached) months, with 10-year survival rates of 65.2%. Surgical negative margin was a positive prognostic factor for radiation-induced benign peripheral nerve sheath tumors. CONCLUSIONS: The risk of incidence of secondary benign peripheral nerve sheath tumors in patients treated with radiotherapy should be considered in long-term follow-up periods. At present, complete surgical resection is the main stay for the treatment of radiation-induced benign peripheral nerve sheath tumors.

Radiation-Induced Glandular Malignant Peripheral Nerve Sheath Tumor.

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue tumors. They can occur in patients with neurofibromatosis type-1 (NF-1) or as sporadic tumors. Only 10% of MPNSTs are radiation induced. Divergent differentiation in MPNSTs can occur in 15% of cases and may include cartilage, bone, skeletal muscle, blood vessels, and very rarely well-formed glands, the latter typically described in NF-1-associated MPNSTs. We report an exceedingly rare case of radiation induced glandular MPNST arising in a neurofibroma of the femoral nerve in a patient previously irradiated for endometrial carcinoma.

Intradural Schwannoma Exacerbating the Symptoms of Degenerative Lumbar Stenosis: Case Report

Introduction Schwannoma is a common intradural slow-growing, benign and encapsulated tumor that originates from the myelin sheaths of the nerve fibers. However, a lumbar schwannoma complicating the symptoms of spinal stenosis is an extremely rare association. Aim To describe the case of a woman presenting a lumbar schwannoma in association with spinal stenosis. Case Report A 53 year-old female was referred to neurosurgical evaluation due to the worsening of a lumbar pain that was irradiating to the left inferior leg along the anterolateral surface. A neurological examination revealed motor deficits for extension of the left leg and attenuation of the left patellar reflex. Magnetic resonance imaging (MRI) showed lumbar spinal stenosis due to flavum ligament hypertrophy and disc herniation in the L3L4 and L4L5 segments, and an expansive lesion with homogeneous contrast enhancement occupying the left neuroforamen of the L3L4 segment. The patient underwent surgical resection of the tumor and decompression of the stenotic segments with posterior screw instrumentation from L3 to L5. She presented an uneventful recovery and significant improvement of the lumbar pain, and was still free of symptoms 6 months after surgery. An anatomopathological examination defined the tumor as a schwannoma (Grade I ­ World Health Organization [WHO]). Conclusion The present study highlights that lumbar schwannoma is a possible etiology complicating the symptoms of patients with previous lumbar spinal stenosis. It is important to treat both pathologies to improve the patients' symptoms.

Introdução O schwannoma é um tumor intradural comum, benigno, de crescimento lento e encapsulado que se origina da bainha de myelina das fibras nervosas. No entanto, a presença de um schwannoma lombar complicando os sintomas de estenose do canal medular é uma associação extremamente rara. Objetivos Descrever o caso de uma paciente portadora de schwannoma lombar exacerbando os sintomas de estenose do canal lombar. Relato de Caso Uma mulher de 53 anos de idade foi encaminhada para avaliação neurocirúrgica devido a relato de piora dos sintomas de dor lombar que irradiavam preferencialmente para o membro inferior esquerdo na sua face antero-lateral. O exame físico neurológico revelou a presença de déficit motor para a extensão do membro inferior esquerdo e redução do reflexo patelar esquerdo. A imagem de ressonância magnética mostrou a presença de estenose do canal lombar devido à hipertrofia do ligamento amarelo e herniações discais nos segmentos L3L4 e L4L5. Além disso, o estudo radiológico também evidenciou a presença de uma lesão expansiva ocupando o neuroforamen de L3L4 com captação homogênea do meio de contraste. A paciente foi submetida à ressecção cirúrgica do processo neoplásico e descompressão do canal medular com artrodese através de instrumentação dos segmentos L3L4L5 via posterior em um único ato operatório. A paciente apresentou uma recuperação pós-operatória adequada e mantém-se assintomática em segmento clínico seis meses após o procedimento cirúrgico. O estudo anatomo-patológico e imuno-histoquímico definiu o processo expansivo como schwannoma (Grau I da OMS). Conclusão O presente estudo destaca que o schwannoma lombar é uma possibilidade etiológica para os pacientes portadores de estenose do canal lombar que apresentam piora progressiva dos sintomas ou novos déficits neurológicos. É importante tratar as duas patologias para que o paciente obtenha melhor resultado clínico no controle dos sintomas.