[Lipomatous ependymomas of the posterior fossa. An infrequent and little-known subtype. A case report and review of the literature]. / Ependimomas lipomatosos de la fosa posterior. Un subtipo muy infrecuente y poco conocido. Presentación de caso y revisión de la literatura.

Ependymomas are well defined glial tumours composed of uniform small cells with round nuclei in a fibrillar matrix. They have characteristic perivascular acellular areas (pseudorosettes) and, in some cases, ependymal rosettes. The three most well-known histological phenotypes are papillary, clear-cell and tanycytic. The WHO classification includes rare cases of ependymoma with lipomatous metaplasia. Lipomatous ependymomas of the posterior fossa are extremely rare; we only found 7reports of cases in adults. They usually arise in the fourth ventricle and may extend into the cerebellum, when they often show extensive vacuolization, pushing the nucleus to the periphery and giving rise to a signet-ring cell appearance. Radiologically, there are few findings characteristic of these tumours. Immunohistochemistry is essential to differentiate this subtype from other more common lesions, such as metastatic adenocarcinoma, especially from breast, intestine and kidney.

Ependimomas lipomatosos de la fosa posterior. Un subtipo muy infrecuente y poco conocido. Presentación de caso y revisión de la literatura / Lipomatous ependymomas of the posterior fossa. An infrequent and little-known subtype. A case report and review of the literature

Los ependimomas son tumores gliales bien circunscritos compuestos de células pequeñas uniformes con un núcleo redondo en una matriz fibrilar. Se caracterizan por zonas anucleadas perivasculares (pseudorrosetas) y, en algunos casos, rosetas ependimarias. Tres fenotipos histológicos son los más reconocidos: papilar, de células claras y tanicítico. La OMS reconoce casos raros de ependimomas con metaplasia lipomatosa. Los ependimomas lipomatosos de fosa posterior son extremadamente infrecuentes, y en nuestra búsqueda hemos encontrado 7casos reportados en la literatura (excluyendo niños). Se originan habitualmente del 4.° ventrículo y podrían presentar extensión cerebelosa. Estos suelen presentar extensa vacuolización empujando el núcleo a la periferia y simulando la apariencia de «signet-ring cells» (células en anillo de sello). Radiológicamente hay pocos hallazgos que sean característicos de este tipo de tumores. La inmunohistoquímica es decisiva para no confundir esta variante con lesiones más comunes, como el adenocarcinoma metastásico, especialmente los de mama, intestino y renal.(AU)

Ependymomas are well defined glial tumours composed of uniform small cells with round nuclei in a fibrillar matrix. They have characteristic perivascular acellular areas (pseudorosettes) and, in some cases, ependymal rosettes. The three most well-known histological phenotypes are papillary, clear-cell and tanycytic. The WHO classification includes rare cases of ependymoma with lipomatous metaplasia. Lipomatous ependymomas of the posterior fossa are extremely rare; we only found 7reports of cases in adults. They usually arise in the fourth ventricle and may extend into the cerebellum, when they often show extensive vacuolization, pushing the nucleus to the periphery and giving rise to a signet-ring cell appearance. Radiologically, there are few findings characteristic of these tumours. Immunohistochemistry is essential to differentiate this subtype from other more common lesions, such as metastatic adenocarcinoma, especially from breast, intestine and kidney.(AU)

Durable benefit and change in TCR clonality with nivolumab in a Lynch syndrome-associated glioma.

Germline replication-repair deficient (gRRD) gliomas are exceptional events, and only a few of them have been treated with immune checkpoint inhibitors (ICIs). Contrary to sporadic gliomas, where ICIs have failed to show any objective benefit, the very few patients with gRRD gliomas treated with ICIs to date seem to benefit from programmed-death-1 (PD-1) inhibitors, such as nivolumab or pembrolizumab, either in terms of durable responses or in terms of survival. T-cell immunohistochemistry (IHC) and T-cell receptor (TCR) repertoire using high-throughput next-generation sequencing (NGS) with the Oncomine TCR-Beta-SR assay (Thermo Fisher Scientific) were analyzed in pre- and post-nivolumab tumor biopsies obtained from a patient with a Lynch syndrome-associated glioma due to a germline pathogenic hMLH1 mutation. The aim was to describe changes in the T-cell quantity and clonality after treatment with nivolumab to better understand the role of acquired immunity in gRRD gliomas. The patient showed a slow disease progression and overall survival of 10 months since the start of anti-PD-1 therapy with excellent tolerance. A very scant T-cell infiltrate was observed both at initial diagnosis and after four cycles of nivolumab. The drastic change observed in TCR clonality in the post-nivolumab biopsy may be explained by the highly spatial and temporal heterogeneity of glioblastomas. Despite the durable benefit from nivolumab, the scant T-cell infiltrate possibly explains the lack of objective response to anti-PD-1 therapy. The major change in TCR clonality observed after nivolumab possibly reflects the evolving molecular heterogeneity in a highly pre-treated disease. An in-deep review of the available literature regarding the role of ICIs in both sporadic and gRRD gliomas was conducted.

Enfermedad de Erdheim-Chester, una gran imitadora. Presentación de casos y revisión de la literatura / Erdheim-Chester disease, an incredible simulator. Cases reports and review of literature

La enfermedad de Erdheim-Chester es una histiocitosis no-Langerhans. Hasta 2014 han sido reportados alrededor de 550 casos, y está catalogada como enfermedad rara según la European Rare Disease Organization y la National Organization for Rare Disorders. La clínica más frecuente es dolor óseo en miembros inferiores y generalmente aparece entre la 5.a -7.a década. El diagnóstico se basa en inmunohistoquímica S100(+/-), CD68(+) y CD1a(-), estos 2 últimos suficientes y mandatorios para el diagnóstico. El mejor tratamiento consiste en administrar interferón-alfa o interferón-alfa2-pegilado. La supervivencia es del 96% al año y del 68% a los 5 años, siendo menor en casos con afectación del sistema nervioso central. Presentamos 2 casos con afectación aislada del sistema nervioso central al diagnóstico, siendo muy pocos los casos publicados con esta forma de presentación. También observamos que estos pacientes presentaron recidivas o nuevas lesiones a los 8 meses por lo que proponemos seguimiento con RMN cerebral y PET toracoabdominal cada 3-4 meses

Erdheim-Chester disease is a non-Langerhans histiocytosis. Until 2014 at least 550 cases have been reported. According to European Rare Disease Organization and National Organization for Rare Disorders it is a rare disease. The most common symptom is bone pain in the lower extremities and it usually appears between the 5 th and 7 th decades of life. The diagnostic is based on immunohistochemical results: S100(+/-), CD68(+), and CD1a(-), the latter 2 are mandatory. The best treatment nowadays is alpha-interferon or pegylated alpha-2. The overall survival is 96% at one year and 68% at 5 years. Central nervous system involvement is associated with a worse outcome. Two cases are presented with central nervous system lesions in the absence of lesions in other organs on their onset. Very few cases have been reported with this kind of presentation. We also noted that these patients had recurrences or new lesions at 8 months. A follow-up is proposed with brain MRI and thoraco-abdominal PET every 3-4 months

[Erdheim-Chester disease, an incredible simulator. Cases reports and review of literature]. / Enfermedad de Erdheim-Chester, una gran imitadora. Presentación de casos y revisión de la literatura.

Erdheim-Chester disease is a non-Langerhans histiocytosis. Until 2014 at least 550 cases have been reported. According to European Rare Disease Organization and National Organization for Rare Disorders it is a rare disease. The most common symptom is bone pain in the lower extremities and it usually appears between the 5th and 7th decades of life. The diagnostic is based on immunohistochemical results: S100(+/-), CD68(+), and CD1a(-), the latter 2 are mandatory. The best treatment nowadays is alpha-interferon or pegylated alpha-2. The overall survival is 96% at one year and 68% at 5 years. Central nervous system involvement is associated with a worse outcome. Two cases are presentedwith central nervous system lesions in the absence of lesions in other organs on their onset. Very few cases have been reported with this kind of presentation. We also noted that these patients had recurrences or new lesions at 8 months. A follow-up is proposed with brain MRI and thoraco-abdominal PET every 3-4 months.

C8-T1 Radiculopathy Due to an Intradural Extramedullary Metastasis of a Pancreatic Neuroendocrine Tumor: Case Report and Review of the Literature.

Pancreatic neuroendocrine tumors (pNETs) are usually well-to-moderately differentiated neuroendocrine tumors (NETs) that most often metastasize to the liver and lymph nodes with other locations being uncommon. We present a case of intradural pNET metastasis and conduct a review of the literature. Forty-five cases, including the case presently reported, of spinal cord compression due to well-differentiated NETs were found: carcinoid (80%), pNET (13.3%), and NETs of unknown primary (6.7%). Seventy-eight percent of cases consisted of extradural compressions from vertebral bone metastases, whereas there were only 5 cases of intradural extramedullary spinal cord compression. Most cases were managed with surgery and/or radiotherapy with a good clinical outcome in the majority. We report the first case of a pNET intradural extramedullary metastasis and conduct the largest review to date of an infrequent complication of well-differentiated NETs such as malignant spinal cord compression. Aggressive local treatment is warranted in most cases because it usually achieves neurologic improvement and symptomatic relief in patients who may still have a long life expectancy.

Predictive factors for craniopharyngioma recurrence: a systematic review and illustrative case report of a rapid recurrence.

BACKGROUND: Recurrence of craniopharyngiomas (CPs) represents a frequent and unpredictable incident. Rapid tumor recurrence within a few months after surgery has been rarely reported. Nondefinitive predictive factors for rapid CP recurrence have been identified to date. We have systematically analyzed the tumor factors that presumably influence in CP recurrence. METHODS: We present the histologic and immunohistochemical analysis of an infundibulo-tuberal CP that was operated twice within a 3-month interval due to rapid recurrence. We investigated the differential characteristics of the subgroup of CPs that recurred in large surgical series published in the literature, along with cases reporting rapid tumor recurrence after surgery. RESULTS: Specimens of our patient showed an adamantinomatous CP with whorl-like arrays and thick peritumoral gliosis. Ki-67 labeling index in primary and recurrent samples was 20% and 15%, respectively. p53 labeling index was 18% and 15%, respectively. The thorough analysis of literature showed that presence of tumor remnants and missing radiotherapy treatment after subtotal removal are strong predictors of tumor recurrence. Third ventricle involvement, large tumor size, tight adherence to surrounding structures, and presence of whorl-like arrays might also foster recurrence. High Ki-67 levels, p53 expression, and an intense reactive gliosis might point to rapid tumor growth. CONCLUSIONS: Reliable tumor markers that predict CP recurrence are still lacking. The CP features presumably related to a higher risk of its recurrence are thought to be a larger tumor size, a tight adherence to the hypothalamus, the presence of whorl-like arrays, and high Ki-67 and p53 levels.

Ependymal cyst of the midbrain.

We present the case of a 30-year-old man who developed an acute hydrocephalus secondary to an obstruction of the cerebral aqueduct by a midbrain cystic lesion. After a ventriculo-peritoneal shunt was placed to relief symptoms of intracranial hypertension, the patient underwent a neuronavigation-assisted endoscopic fenestration of the cyst. A careful immunohistochemical staining confirmed the diagnosis of an ependymal cyst. An extensive review of the literature has revealed that this is the first report of a periaqueductal ependymal cyst with definite histological diagnosis. This is a rare cause of acute non-communicating hydrocephalus but an important entity in the differential diagnosis.

Acute epidural-like appearance of an encapsulated solid non-organized chronic subdural hematoma.

We report the exceptional case of an encapsulated solid non-organized chronic subdural hematoma (SDH) in a 67-year-old woman that was admitted with acute hemiplegia followed by rapid deterioration in consciousness 5 months after a minor head trauma. Computed tomography (CT) showed an extracerebral biconvex shaped hyperdense mass that led to the misdiagnosis of an acute epidural hematoma. Urgent craniotomy revealed an encapsulated mass filled with solid fresh clot in the subdural space. Complete evacuation of this SDH, including both its inner and outer membranes, was achieved, and the patient recovered successfully. Histological analysis confirmed that the content of the hematoma corresponded to a newly formed clot that was enclosed between an inner membrane, composed of two collagen layers, and an outer membrane with a three layered structure. Chronic SDH may seldom present as an encapsulated solid non-organized lesion that consists of a fibrous capsule enclosing a fresh clot and lacking the thick fibrous septations that typically connect the inner and outer membranes of organized chronic SDH. This entity mimics the clinical course and radiological appearance of acute epidural hematomas and should be considered in the differential diagnosis of extracerebral hyperdense biconvex shaped lesions.