Clinical effect of pituitary cystectomy in thirty-two patients / 中国医师进修杂志

Objective:To discuss the surgical efficacy of neuroendoscopic transsphenoidal approach for the removal of pituitary cystic lesion.Methods:Clinical data and efficacy of 32 patients with neuroendoscopic transsphenoidal surgery and pathological diagnosis of pituitary cystic lesion in the Affiliated Hospital of Jining Medical University from March 2013 to May 2019 were retrospectively analyzed.Results:Of the 32 patients, 29 patients were pathologically diagnosed with Rathke cysts and 3 patients with pituitary arachnoid cysts. The content of cyst could be completely removed and the relationship between cyst and sellarseptum and subarachnoid space could be clearly observed by using endoscopy. After followed-up for 0.5-1.0 year, headic, dizziness and visual impairment were improved. One patient relapsed, without serious complications or death.Conclusions:Transsphenoidal neuroendoscopic surgery is a safe and effective treatment for pituitary cystic lesion.

Physiopathological Aspects of Sellar Epidermoid Cyst Determining Endocrine Disturbances: A Case Report

Epidermoid cysts (ECs) of the central nervous system (CNS) constitute benign circumscribed lesions that aremore common in lateral than in midline sites. Epidermoid cysts of the CNS arise more frequently in the cerebellopontine angle, around the pons, near the sella, within the temporal lobe, in the diploe, and in the spinal canal. Most common tumoral lesion of sellar region is pituitary adenoma, and sellar cystic epithelial masses may be difficult to differentiate based only on clinical and imaging findings. Epidermoid cysts are covered by keratinized squamous epithelium and are usually filled with keratin lamellae. The process is, for the most part, maldevelopmental in origin, presumably arising from trapped surface ectodermal elements in association with the developing CNS during the closure of the neural groove or formation of the secondary cerebral vesicles. In the present study, the authors describe a case of sellar epidermoid cyst producing endocrine alterations and visual disturbance in a 35 years woman, and review the physiopathological and diagnostic criteria of this lesion.

Spontaneously Regressed Rathke's Cleft Cyst

We report two rare cases of spontaneously regressed Rathke's cleft cyst (RCC). A 52-year-old woman presented with headache. A pituitary hormone study was normal. Brain magnetic resonance imaging (MRI) showed a 0.45-cm³ cystic sellar lesion. The cyst was hyperintense on T1-weighed imaging and hypointense on T2-weighted imaging without rim enhancement, comparable to a RCC. Six months later, brain MRI showed no change in the cyst size. Without any medical treatments, brain MRI 1 year later revealed a spontaneous decrease in cyst volume to 0.05 cm³. A 34-year-old woman presented with headache and galactorrhea lasting 1 week. At the time of the visit, the patient's headache had disappeared. Her initial serum prolactin level was 81.1 ng/mL, and after 1 week without the cold medicine, the serum prolactin level normalized to 11.28 ng/mL. Brain MRI showed a RCC measuring 0.71 cm³. Without further treatments, brain computed tomography 6 months later showed a spontaneous decrease in cyst volume to 0.07 cm³. Another 6 months later, brain MRI revealed that the cyst had remained the same size. Neither patient experienced neurological symptoms, such as headache or visual disturbance, during the period of cyst reduction. The RCCs in both patients underwent spontaneous regression without any medical treatment during a period of 6 months to 1 year. Although spontaneous regression of a RCC is rare, it is still possible and a sufficient follow-up period should be considered.

Magnetic resonance imaging characteristics and differential diagnosis of common sellar cystic lesions / 中华耳鼻咽喉头颈外科杂志

Objective@#To investigate magnetic resonance imaging (MRI) characteristic and differential diagnostic keypoints of common sellar regional cystic lesions with the purpose of improving differential diagnostic accuracy.@*Methods@#In total, 174 cases of the pathologically diagnosed cystic lesions in sellar region between March 2016 and June 2019 were included in the current retrospective analysis. These cases included Rathke′s cleft cyst (n=68), craniopharyngioma (n=48), pituitary adenoma (n=56) and arachnoid cyst (n=2) in the sellar region. The position, texture and morphology of leisions, signal of cystic and solid part, invasion of surrounding tissues and maximum diameter of cysts on the MRI images were evaluated and compared between different groups. SPSS 25.0 software was used for statistical analysis.@*Results@#There were several specific changes on several MRI sequences in Rathke′s cleft cysts, craniopharyngioma and pituitary adenoma groups. For Rathke′s cleft cysts, round shape, rare polycystic structure, lack of solid part and maximum diameter of cysts which was significantly less than that of craniopharyngioma and pituitary adenoma groups ((17.37±6.12) mm vs (30.29±13.51) mm vs (28.18±11.13) mm, t value was 6.680, 5.838, respectively, all P<0.05), were favorable diagnostic criteria. While, the intracystic nodules were mostly found in craniopharyngioma. There was no high signal intensity in cystic wall on T1WI and T2WI of pituitary adenoma. MRI signal of arachnoid cyst in sellar region was basically the same as CSF signal, with low signal intensity on T1WI and DWI, high signal intensity on T2WI, without enhanced signal.@*Conclusions@#Common sellar regional cystic lesions showed characteristic manifestations on different MRI sequences. Valuable information in the morphology, MRI signal intensity, maximum diameter measurements may improve accuracy of differential diagnosis for sellar regional cystic lesions.

Diagnosis and prognosis of fetal periventricular pseudocysts / 中华围产医学杂志

Objective@#To investigate the diagnosis, clinical outcomes and factors influencing the prognosis of fetal periventricular pseudocysts (PVPC).@*Methods@#A retrospective analysis was performed on the results of fetal neurosonography (NSG), cranial magnetic resonance imaging (MRI), chromosome karyotype and neonatal cranial ultrasound of 76 PVPC cases detected by prenatal ultrasound in Peking University First Hospital from May 2014 to October 2018. The accuracy of NSG and cranial MRI in PVPC diagnosis was assessed. Prognosis of PVPC and the influencing factors were evaluated. Statistical analysis was performed using Chi-square test or Fisher's exact test.@*Results@#(1) This study involved 51 cases (67.1%) of isolated PVPC and 25 cases (32.9%) of non-isolated PVPC. Among the 25 non-isolated PVPC cases, 15 were complicated by one abnormality and 10 by multiple abnormalities. There were 20 cases with intracranial abnormalities, two with extracranial abnormalities, and three with both intracranial and extracranial abnormalities. (2) Eight out of the 76 pregnancies (10.5%) were terminated and among them, two were isolated PVPC cases, five complicated by determined abnormalities (one case of PVPC complicated with pachygyria and bilateral mild fetal ventriculomegaly, one case of PVPC complicated with pachygyria or agyria and agenesis of corpus callosum, one case of PVPC complicated with arachnoid cyst and vermis dysplasia, one case of PVPC complicated with cortical dysplasia, one case of PVPC complicated with intestinal dilatation) and one by abnormalities of undertermined prognosis (PVPC combined with mild fetal ventriculomegaly and polyhydramnios). A total of 61 neonates (80.3%, 61/76) were born alive and followed up. Seven cases (9.2%, 7/76) were lost to follow-up. (3) As of February 2019, among the 61 followed-up infants, 44 with isolated PVPC and 15 with unclear abnormalities developed well. The other two with determined intracranial abnormalities were diagnosed as having cystic lesions in the brain parenchyma. One of them died of respiratory failure two days after birth and the other suffered from chromosomal disease (13.23 Mb deletion in region q24.3q31.2 of chromosome 2) with mental retardation and delayed growth and development. (4) A total of 44 (57.9%, 44/76) neonates received cranial ultrasound after birth and confirmed the diagnosis of PVPC, among which 11 (25.0%, 11/44) were missed or misdiagnosed in prenatal MRI.@*Conclusions@#PVPC may have many comorbidities, particularly intracranial abnormalities, which are closely related to the prognosis. A thorough prenatal ultrasound examination is necessary for fetal PVPC, especially NSG. Isolated PVPC usually has a good outcome. However, PVPC complicated by cystic lesions in the brain parenchyma may be associated with chromosomal abnormalities, hence fetal chromosome examination is required.

Spontaneously Regressed Rathke's Cleft Cyst

We report two rare cases of spontaneously regressed Rathke's cleft cyst (RCC). A 52-year-old woman presented with headache. A pituitary hormone study was normal. Brain magnetic resonance imaging (MRI) showed a 0.45-cm³ cystic sellar lesion. The cyst was hyperintense on T1-weighed imaging and hypointense on T2-weighted imaging without rim enhancement, comparable to a RCC. Six months later, brain MRI showed no change in the cyst size. Without any medical treatments, brain MRI 1 year later revealed a spontaneous decrease in cyst volume to 0.05 cm³. A 34-year-old woman presented with headache and galactorrhea lasting 1 week. At the time of the visit, the patient's headache had disappeared. Her initial serum prolactin level was 81.1 ng/mL, and after 1 week without the cold medicine, the serum prolactin level normalized to 11.28 ng/mL. Brain MRI showed a RCC measuring 0.71 cm³. Without further treatments, brain computed tomography 6 months later showed a spontaneous decrease in cyst volume to 0.07 cm³. Another 6 months later, brain MRI revealed that the cyst had remained the same size. Neither patient experienced neurological symptoms, such as headache or visual disturbance, during the period of cyst reduction. The RCCs in both patients underwent spontaneous regression without any medical treatment during a period of 6 months to 1 year. Although spontaneous regression of a RCC is rare, it is still possible and a sufficient follow-up period should be considered.

Diagnosis and prognosis of fetal periventricular pseudocysts / 中华围产医学杂志

Objective To investigate the diagnosis, clinical outcomes and factors influencing the prognosis of fetal periventricular pseudocysts (PVPC). Methods A retrospective analysis was performed on the results of fetal neurosonography (NSG), cranial magnetic resonance imaging (MRI), chromosome karyotype and neonatal cranial ultrasound of 76 PVPC cases detected by prenatal ultrasound in Peking University First Hospital from May 2014 to October 2018. The accuracy of NSG and cranial MRI in PVPC diagnosis was assessed. Prognosis of PVPC and the influencing factors were evaluated. Statistical analysis was performed using Chi-square test or Fisher's exact test. Results (1) This study involved 51 cases (67.1%) of isolated PVPC and 25 cases (32.9%) of non-isolated PVPC. Among the 25 non-isolated PVPC cases, 15 were complicated by one abnormality and 10 by multiple abnormalities. There were 20 cases with intracranial abnormalities, two with extracranial abnormalities, and three with both intracranial and extracranial abnormalities. (2) Eight the 76 pregnancies (10.5%) were terminated and among them, two were isolated PVPC cases, five complicated by determined abnormalities (one case of PVPC complicated with pachygyria and bilateral mild fetal ventriculomegaly, one case of PVPC complicated with pachygyria or agyria and agenesis of corpus callosum, one case of PVPC complicated with arachnoid cyst and vermis dysplasia, one case of PVPC complicated with cortical dysplasia, one case of PVPC complicated with intestinal dilatation) and one by abnormalities of undertermined prognosis (PVPC combined with mild fetal ventriculomegaly and polyhydramnios). A total of 61 neonates (80.3%, 61/76) were born alive and followed up. Seven cases (9.2%, 7/76) were lost to follow-up. (3) As of February 2019, among the 61 followed-up infants, 44 with isolated PVPC and 15 with unclear abnormalities developed well. The other two with determined intracranial abnormalities were diagnosed as having cystic lesions in the brain parenchyma. One of them died of respiratory failure two days after birth and the other suffered from chromosomal disease (13.23 Mb deletion in region q24.3q31.2 of chromosome 2) with mental retardation and delayed growth and development. (4) A total of 44 (57.9%, 44/76) neonates received cranial ultrasound after birth and confirmed the diagnosis of PVPC, among which 11 (25.0%, 11/44) were missed or misdiagnosed in prenatal MRI. Conclusions PVPC may have many comorbidities, particularly intracranial abnormalities, which are closely related to the prognosis. A thorough prenatal ultrasound examination is necessary for fetal PVPC, especially NSG. Isolated PVPC usually has a good outcome. However, PVPC complicated by cystic lesions in the brain parenchyma may be associated with chromosomal abnormalities, hence fetal chromosome examination is required.

Thoracolumbar epidural arachnoid cyst of difficult clinical management: case report / Cisto epidural aracnoídeo tóraco-lombar de difícil tratamento clínico: relato de caso / Quiste aracnoideo epidural toracolumbar de difícil tratamiento clínico: reporte de caso

ABSTRACT Introduction: Among the primary lesions occupying the spinal space, only 1% corresponds to the epidural arachnoid cyst (EAC). This condition is usually asymptomatic, and identified accidentally in imaging tests. In symptomatic cases, total surgical resection is recommended. Objective: To describe a case of EAC refractory to clinical treatment. Methods: A 45-year-old woman had lumbar pain for six years and increased pain in the last months, with irradiation to the left lower limb (corresponding to L1). No other alterations found in the physical examination. Magnetic resonance imaging (MRI) of the spine revealed an intravertebral cystic lesion at T12-L1 level, in the left posterolateral position, causing enlargement of the foramen, and suggesting an epidural arachnoid cyst. Results: Due to failure of the initial clinical treatment, the patient underwent left T12-L1 hemilaminectomy, resection of the cyst and correction of dural failure. The patient progressed with effective pain control and MRI confirmed absence of residual lesion. Conclusion: EAC is more common in men (4:1) and may be congenital or acquired. The most common topography is thoracic (65%). Its clinical presentation is low back pain, lower limb pain and paresthesia. MRI is the method of choice for diagnosis and surgical intervention is restricted to cases that are symptomatic or refractory to clinical treatment, and the prognosis tends to be excellent. We conclude that, in addition to being a rare and commonly asymptomatic condition, an adequate therapeutic approach is essential for complete cure, avoiding intense pain and manifestations that bring about a drastic reduction of functional capacity. Level of evidence: IV. Type of study: Case series.

RESUMO Introdução: dentre as lesões primárias que ocupam o espaço espinhal, apenas 1% corresponde ao cisto epidural aracnoideo (CEA). Esta patologia costuma ser assintomática, identificada acidentalmente em exames de imagem. Já em casos sintomáticos, a ressecção cirúrgica total é recomendada. Objetivos: descrever um caso de CEA refratário a tratamento clínico. Metódos: mulher, 45 anos, lombalgia há seis anos, com piora nos últimos meses e irradiação para membro inferior esquerdo (correspondente a L1). Sem demais alterações ao exame físico. A Ressonância magnética (RM) de coluna vertebral evidenciou lesão cística intravertebral a nível de T12 - L1, em situação póstero-lateral esquerda, provocando alargamento do forame, sugestivo de cisto epiduralaracnóideo. Resultados: Devido a falha do tratamento clínico inicial, a paciente foi submetida a hemilaminectomia de T12 - L1 à esquerda, ressecção do cisto e correção da falha dural. Evoluiu com controle álgico efetivo e RM de controle confirmou ausência de lesão residual. Conclusão: O CEA é mais comum em homens (4:1) e pode ser congênito ou adquirido. A topografia mais comum é a nível torácico (65%). Apresenta-se clinicamente com lombalgia, dor em membros inferiores e parestesias. A RM é o método diagnóstico de escolha e a intervenção cirúrgica é restrita aos casos sintomáticos ou refratários ao tratamento clínico e o prognóstico tende a ser excelente. Concluímos que, além de ser uma patologia rara e comumente assintomática, é essencial a adequada abordagem terapêutica para que ocorra cura completa, evitando quadros álgicos intensos e manifestações que cursem com drástica redução da capacidade funcional. Nível de evidência: IV. Tipo de Estudo: Série de casos.

RESUMEN Introducción: Entre las lesiones primarias que ocupan el espacio espinal, solo el 1% corresponde al quiste aracnoideo epidural (QAE). Esta patología generalmente es asintomática e identificada accidentalmente en pruebas de imagen. En casos sintomáticos, se recomienda la resección quirúrgica total. Objetivo: Describir un caso de QAE refractario al tratamiento clínico. Métodos: Mujer de 45 años tuvo dolor lumbar durante seis años y un aumento del dolor en los últimos meses, con irradiación a la extremidad inferior izquierda (que corresponde a L1). No se encontraron otras alteraciones en el examen físico. La resonancia magnética (RM) de la columna vertebral reveló una lesión quística intravertebral en el nivel T12-L1, en la posición posterolateral izquierda, causando agrandamiento del foramen y sugiriendo un quiste aracnoideo epidural. Resultados: Debido a la falla del tratamiento clínico inicial, la paciente fue sometida a hemilaminectomía T12-L1 izquierda, resección del quiste y corrección de la falla dural. Ella progresó con un control eficaz del dolor y la RM confirmó la ausencia de lesión residual. Conclusión: EL QAE es más común en hombres (4:1) y puede ser congénito o adquirido. La topografía más común es torácica (65%). Su presentación clínica es lumbalgia, dolor en las extremidades inferiores y parestesia. La RM es el método de elección para el diagnóstico y la intervención quirúrgica se limita a los casos que son sintomáticos o refractarios al tratamiento clínico, y el pronóstico tiende a ser excelente. Concluimos que, además de ser una condición rara y comúnmente asintomática, un abordaje terapéutico adecuado es esencial para una curación completa, evitando el dolor intenso y las manifestaciones que provocan una reducción drástica de la capacidad funcional. Nivel de evidencia: IV. Serie de casos.

Down syndrome with asymptomatic neuroglial cyst: A case report and review of the literature

Down syndrome (DS, trisomy 21) is associated with neuroanatomical abnormalities, including choroid plexus cysts and various types of brain tumors. Trisomy 21 is associated with oncogenic factor, especially in brain tumor. The brain of DS patients had a smaller volume of gray and white matter and an unbalanced cerebellum volume, indicating a smaller volume overall than normal. We report a case of a DS male patient who had an incidentally discovered neuroglial cyst in left cerebellar vermis. He visited our hospital with gait disturbance and fatigue. But, the neurologic exam was normal. To the best of our knowledge, this is the first reported case of a neuroglial cyst in a trisomy 21 patient. As the developmental mechanisms of a cyst and the choroid plexus are related, more research is needed.

Clinical manifestations of Rathke’s cleft cysts and their natural progression during 2 years in children and adolescents

PURPOSE: Rathke’s cleft cyst (RCC) is an asymptomatic benign lesion. With increased interest in pediatric endocrinology, the prevalence of RCCs in children is also increasing. However, the clinical relevance and proper management of RCC is not well defined in children. Therefore, we investigated the clinical manifestations and radiologic features of RCC in children and adolescents, as well as the natural progression of RCC. METHODS: We retrospectively reviewed the medical records of 91 children and adolescents with RCC diagnosed with magnetic resonance imaging (MRI) in Severance Children’s Hospital from January 2006 to December 2015. The clinical, hormonal, and imaging findings were analyzed in patient groups classified according to age. The size of each cyst was assessed in sixty patients who underwent follow-up MRI during the 2 years. RESULTS: Female patients were predominant (64 vs. 27). The common clinical features at presentation were endocrine dysfunction (59.3%), headache (23.0%), and dizziness (4.4%). Symptoms related to endocrine disorders were more frequent in younger patients. In 7 patients managed surgically, the cysts were significantly larger and more frequently located in the suprasellar region. Of 60 nonsurgical patients with a follow-up MRI performed within 2 years after the diagnosis, the RCC size increased in about 26.7% (n=16). CONCLUSION: Although 94.4% of the patients with RCC had clinical symptoms, surgery was performed in only about 7.5% of patients. RCC is associated with pituitary insufficiency, thus, baseline and follow-up endocrine function tests are required. Additionally, regular MRI follow-up is required in long-term period to monitor change in size.

Giant hypothalamic hamartoma associated with an intracranial cyst in a newborn

We report the case of a giant hypothalamic hamartoma with a large intracranial cyst in a neonate. On ultrasonography, the lesion presented as a lobulated, mass-like lesion with similar echogenicity to the adjacent brain parenchyma, located anterior to the underdeveloped and compressed left temporal lobe, and presenting as an intracranial cyst in the left cerebral convexity without definite internal echogenicity or septa. The presence of a hypothalamic hamartoma and intracranial neurenteric cyst were confirmed by surgical biopsy. The association of a giant hypothalamic hamartoma and a neurenteric cyst is rare. Due to the rarity of this association, the large size of the intracranial cyst, and the resulting distortion in the regional anatomy, the diagnosis of the solid mass was not made correctly on prenatal high-resolution ultrasonography.

Clinical and radiological findings of incidental Rathke's cleft cysts in children and adolescents

PURPOSE: In the pediatric population, Rathke's cleft cysts (RCCs) are known to be an infrequent cause of headaches, visual disturbances, and pituitary dysfunction. We investigated the clinical characteristics of children in whom RCCs were incidentally discovered and evaluated whether RCCs influence the treatment response of patients with proven endocrinopathy. METHODS: A retrospective analysis was conducted in 34 patients with RCCs who were diagnosed between 2006 and 2013 at Hallym University Medical Center. Their clinical, hormonal, and imaging findings were reviewed. We evaluated the clinical outcomes of the patients with concomitant RCCs and endocrinopathy compared to matched controls. RESULTS: Twenty-six of 34 patients with radiologically proven RCCs had endocrine disorders. They were 9 boys and 17 girls, with ages ranging from 4.8 to 17.4 years at the time of the diagnosis. Of these, 7 (27%) had idiopathic short stature, 7 (27%) had growth hormone deficiency (GHD), and 12 (46%) had central precocious puberty (CPP). Nineteen of 26 patients (73.1%) showed low signal intensities on T1-weighted images (T1WI) and high signal intensities on T2-weighted images. The incidence of hypointensity on T1WI was higher in the patients with RCCs accompanied by endocrinopathy than in those without endocrinopathy (P=0.033). The treatment outcomes of the patients with CPP and GHD with and without RCCs were similar. CONCLUSION: CPP and GHD patients with a small RCC (less than 20 mm) expressing cystic magnetic resonance intensity can be managed with medical treatment, although the RCCs need to be closely monitored in radiological studies to observe their growth.

Resolução espontânea de cisto aracnóideo suprasselar / Spontaneous resolution of a suprasellar arachnoid cyst

Cisto aracnóideo é uma coleção de líquido semelhante ao liquor, de parede formada por membranas aracnoides reforçadas por fibras colágenas. É uma anomalia congênita, benigna e rara, correspondendo a aproximadamente 1% das lesões expansivas intracranianas. Geralmente, os cistos aracnóideos (CAr) localizam-se na fossa média e, em apenas 10% dos casos, na região suprasselar. A involução espontânea dos CAr é um fato raro e pouco descrito na literatura. Relata-se um CAr suprasselar diagnosticado intraútero cuja conduta foi conservadora, observando-se sua involução espontânea à ressonância magnética de controle aos 24 meses de vida.

Arachnoid cyst is a benign fluid collection, formed by arachnoid bands. It is a rare congenital abnormality, representing approximately 1% of all intracranial expanding lesions. Generally, the arachnoid cysts (CAr) are located in the middle cranial fossa and only 10% occur in the suprasellar region. The spontaneous resolution of CAr is indeed a rare and poorly described evolution reported in the literature. We report a gestational diagnosed suprasellar cyst with spontaneous resolution at the 24th month old.

Clinical and Neuroimaging Outcomes of Surgically Treated Intracranial Cysts in 110 Children

OBJECTIVE: The indications and optimal surgical treatments for intracranial cysts are controversial. In the present study, we describe long-term clinical and neuroimaging results of surgically treated intracranial cysts in children. The goal of this study is to contribute to the discussion of the debate. METHODS: This study included 110 pediatric patients that underwent surgeries to treat intracranial cysts. Endoscopic cyst fenestrations were performed in 71 cases, while craniotomies and cyst excisions (with or without fenestrations) were performed in 30 patients. Cystoperitoneal shunts were necessary for nine patients. Long-term results were retrospectively assessed with medical and neuroimaging records. RESULTS: Clinical and radiological improvement was reported in 87.3% and 92.8% of cases, respectively, after endoscopic neurosurgery, and in 93.3% and 100% using open microsurgery whereas 88.9% and 85.7% after shunt operation. There were no statistical differences in clinical outcomes (p=0.710) or volume reductions (p=0.177) among the different surgeries. There were no mortalities or permanent morbidities, but complications such as shunt malfunctions, infections, and subdural hematomas were observed in 56% of the patients that had shunt operations. A total of 13 patients (11.8%) underwent additional surgeries due to recurrences or treatment failures. The type of surgery performed did not influence the recurrence rate (p=0.662) or the failure rate (p=0.247). CONCLUSION: Endoscopic neurosurgeries are less invasive than microsurgeries and are at least as effective as open surgeries. Thus, given the advantages and complications of these surgical techniques, we suggest that endoscopic fenestration should be the first treatment attempted in children with intracranial cysts.

Cisto epidermoide da fossa posterior: relato de caso / Epidermoid cyst of the posterior fossa: a case report

Epidermoid cysts of the central nervous system are uncommon conditions, which are frequently located in the cerebellopontine angle and around the pons. They are covered with keratinized squamous epithelium and keratin lamella, which give its contents a soft, white-pearly appearance. Epidermoid cysts are mostly originated from malformations, presumably associated with surface elements of the nervous system ectoderm during the closure of the neural groove or formation of secondary cerebral vesicles. The authors describe a case of epidermoid cyst in the posterior fossa causing hydrocephalus and review morphologic and diagnostic criteria of this lesion.

Os cistos epidermoides do sistema nervoso central (SNC) são condições incomuns, estando localizados mais frequentemente no ângulo pontocerebelar e ao redor da ponte. Eles são revestidos por epitélio escamoso queratinizado e lamelas de queratina, tornando seu conteúdo branco-perolado e pastoso. Os cistos epidermoides são, na maioria das vezes, originados de malformações, possivelmente associados ao entremeio de elementos superficiais do ectoderma do SNC durante o fechamento da placa neural, ou formação das vesículas cerebrais secundárias. Os autores descrevem um caso de cisto epidermoide da fossa posterior determinando hidrocefalia e revisam critérios morfológicos e diagnósticos dessa lesão.