[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)

Eyelid Myokymia with Concomitant Cerebral Tumour: A Case Report.

Eyelid myokymia is a localised movement disorder of the orbicularis oculi muscle with involuntary, fine, continuous, and undulating contractions. Although this entity is thought to be peripheral nerve origin, it rarely occurs with an intracranial lesion. The authors report a case of eyelid myokymia with concomitant cerebral tumour. A 52-year-old woman had a 6-month history of left eyelid myokymia accompanied by upper eyelid ptosis and lower eyelid reverse ptosis. Magnetic resonance imaging showed a solid mass measuring 20 × 25 × 20 mm in the temporal lobe of the cerebral cortex, showing isointense on T1-weighted and hyperintense on T2-weighted images. The clinical diagnosis was cerebral astrocytoma.

[Meningeal metastasis of uterine leiomyosarcoma. Case report and literature review]. / Metástasis meníngea de leiomiosarcoma uterino. Reporte de caso y revisión de literatura.

Brain metastases are the most commonly seen intracranial lesions in adults. What is more, meningiomas are the most common primary intracranial tumours after gliomas and their imaging characteristics are well known in both CT and MRI scans. However, there are lesions that can mimic meningiomas in imaging studies, including metastases of extracranial tumours, confronting us with a diagnostic and therapeutic challenge. We present the case of a patient with meningeal metastasis of a uterine leiomyosarcoma that was not known at the time of the surgical intervention.

In Vivo Tumour Mapping Using Electrocorticography Alterations During Awake Brain Surgery: A Pilot Study.

During awake brain surgery for tumour resection, in situ EEG recording (ECoG) is used to identify eloquent areas surrounding the tumour. We used the ECoG setup to record the electrical activity of cortical and subcortical tumours and then performed frequency and connectivity analyses in order to identify ECoG impairments and map tumours. We selected 16 patients with cortical (8) and subcortical (8) tumours undergoing awake brain surgery. For each patient, we computed the spectral content of tumoural and healthy areas in each frequency band. We computed connectivity of each electrode using connectivity markers (linear and non-linear correlations, phase-locking and coherence). We performed comparisons between healthy and tumour electrodes. The ECoG alterations were used to implement automated classification of the electrodes using clustering or neural network algorithms. ECoG alterations were used to image cortical tumours.Cortical tumours were found to profoundly alter all frequency contents (normalized and absolute power), with an increase in the δ activity and a decreases for the other bands (P < 0.05). Cortical tumour electrodes showed high level of connectivity compared to surrounding electrodes (all markers, P < 0.05). For subcortical tumours, a relative decrease in the γ1 band and in the alpha band in absolute amplitude (P < 0.05) were the only abnormalities. The neural network algorithm classification had a good performance: 93.6 % of the electrodes were classified adequately on a test subject. We found significant spectral and connectivity ECoG changes for cortical tumours, which allowed tumour recognition. Artificial neural algorithm pattern recognition seems promising for electrode classification in awake tumour surgery.