The aim of the study is to evaluate the efficacy of craniotomy and membranectomy as initial treatment of organized chronic subdural hematoma (OCSH). We retrospectively reviewed a series of 34 consecutive patients suffering from OCSH, diagnosed by magnetic resonance imaging (MRI) or contrast computer tomography (CCT) in order to establish the degree of organization and determine the intrahematomal architecture. The indication to perform a primary enlarged craniotomy as initial treatment for non-liquefied chronic subdural hematoma (CSDH) with multilayer loculations was based on the hematoma MRI appearance-mostly hyperintense in both T 1 -and T 2 -weighted images with a hypointense web-or net-like structure within the hematoma cavity. The reason why some hematomas evolve towards a complex and organized architecture remains unclear; the most common aspect to come to light was the "long standing" of the CSDHs which, in our series, had an average interval of 10 weeks between head injury and initial scan. Recurrence was found to have occurred in 2 patients (6% of cases) in the form of acute subdural hematoma. One patient died as the result of an intraventricular and subarachnoid haemorrhage, while 2 patients (6%) suffered an haemorrhagic stroke ipsilateral to the OCSH. Eighty-nine percent of cases had a good recovery, while 11% remained unchanged or worsened. In select cases, based on the MRI appearance, primary enlarged craniotomy seems to be the treatment of choice for achieving a complete recovery and a reduced recurrence rate in OCSH.

Solitary pyogenic thalamic and basal ganglia abscesses are relatively uncommon. Even if widespread antibiotic therapy and modern imaging technologies combined with minimally invasive techniques have improved the outcome in patients with brain abscesses, this is counterbalanced by an increasing population of immunocompromised patients. Basal ganglia, thalamic, brainstem or multiple abscesses are usually of hematogenous origin with an underlying source of infection which can include congenital heart disease, thoracic sepsis or, less frequently, an odontogenic or otogenic source. However, no evident foci of sepsis or predisposing factors may be found. Only a few studies are reported in the literature, because midline abscesses are usually included in studies dealing on the treatment of abscesses in general. Different treatment options and the timing of treatment are described. We report our experience in 3 consecutive cases of thalamic abscess, treated by stereotactic puncture as the first step, followed by histological analysis, external drainage and targeted intrathecal and systemic antibiotic therapy. Deep-seated abscesses seem to behave differently as they are associated with an increased risk of intraventricular rupture and antibiotic resistance, a fact which justifies a more aggressive and immediate surgical treatment. We review the literature on this topic in the last 20 years.

A 58-year-old woman presented to the Department of Neurosurgery, Santo Spirito Hospital, Rome, Italy for increasing paraparesis for almost 1 year. The MRI examination of dorsal spine detected an extramedullary expansive lesion at D6 soma level (Fig. 1a,b); the lesion showed a dural attachment and both plain and contrast-enhanced MRI features suggested a meningioma with areas of calcification.The lesion was completely removed with a posterior approach after D5 and D6 laminectomy.After surgery the patient started a rehabilitation therapy with a good functional improvement after 1 year. PATHOLOGICAL FINDINGSMacroscopically, the lesion was presented as a nodular mass, 1.5 cm in diameter, characterized by a hard texture typical of bone or calcified tissues. The specimen was decalcified in a chlorhydric and formic acid solution, routinely used for bone tissue decalcification, and subsequently embedded in paraffin for histological examination.Histology showed a benign neoplastic lesion composed of meningothelial cells with wide cytoplasm and ill-defined margins, round to ovoid nuclei with no atypia and frequent nuclear pseudoinclusions, with a focal whorl arrangement and several confluent psammoma bodies (Fig. 2a-c). No mitotic figures were observed. The meningothelial proliferation was associated with extensive areas of lamellar bone tissue, with fibrous bone marrow alternating with hematopoietic bone marrow, composed by maturing erythroid and myeloid elements and megakaryocytes (Fig. 2a-c). The periphery of the lesion was mainly composed of the meningothelial component.Immunohistochemistry showed positivity of the meningothelial cells for vimentin and EMA; p53 immunostain was negative; the Ki67 immunoreaction demonstrated an MIB-1 index less than 1% in the meningothelial line, more than 60% in the hematopoietic compartment. A myeloperoxidase immunostain highlighted the presence of a conspicuous maturing myeloid component in the hematopoietic marrow (Fig. 2d). DIAGNOSISThe histomorphological and immunohistochemical features were consistent with a diagnosis of spinal metaplastic meningioma with ossification and hematopoietic bone marrow formation.