Calcifying pseudoneoplasms of the neuraxis: Report on four cases and review of the literature.

OBJECTIVES: Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare lesions occurring anywhere in the central nervous system (CNS). Since their description, only 55 cases have been reported. We present the largest series reviewing their imaging features, histology and potential origins. PATIENTS AND METHODS: four patients with histopathologically verified CAPNON are presented. Subsequently, we review all reports published with respect to study type, number of patients, clinical presentation, anatomical area (intracranial, spinal, or both), radiological features, therapy, histopathologic features, duration of follow-up, complications, and outcome. Moreover, current management of CNS CAPNON are discussed. Autopsy patients were excluded. RESULTS: Four patients with histopathologically verified diagnosis of CAPNON are presented between 46-73 years-old. Three of them were located in the spinal cord (levels C3, D2, and L2) and one intracranial (left atrium). The spine ones were diagnosed due to radicular pain, paraparesis and numbness in lower limb, the intracranial because of intense headache. The differential diagnosis included cavernous malformation, in the case of the lumbar CAPNON this suspicion put back the surgery six months. All cases were surgically treated with complete resection. No recurrence showed at the 12-month follow-up. A total of retrospective 30 articles were selected: 10 case series (33.33%) and 20 reports of single cases (66.66%). The 30 articles and our additional cases added up to a total of 27 patients with spinal CAPNON and 32 patients with intracranial CAPNON. All patients were treated surgically. A follow-up, conducted in 48 patients, showed no signs of recurrence in 46 of the 48. CONCLUSIONS: Calcifying pseudoneoplasms are rare benign lesions of yet unknown origin. They should be taken into consideration in the differential diagnosis of calcified lesions because an inaccurate diagnosis can result in potentially harmful and unnecessary therapies, as prognosis for these lesions is generally favorable.

Primary cerebral radiotherapy-induced rhabdomyosarcoma: treatment with intraoperative carmustine implants.

INTRODUCTION: Primary cerebral rhabdomyosarcomas (cRMS) are extremely rare, with only 41 cases reported in the literature. Survival of patients with localized cRMS is 70% after 5 years but not in the case of intracranial neoplasms, where survival rarely exceeds 10 months. CASE REPORT: A 10-year-old female patient with a history of acute lymphoblastic leukemia (ALL) and holocranial radiotherapy (RT) 6 years ago, referred after partial surgical resection of a left parietal lesion, diagnosed as an embryonal tumor with mixed neuronal-glial differentiation (WHO grade IV). A second operation was performed for complete resection and placement of intracavitary chemotherapy (carmustine). The pathology revealed a high-grade undifferentiated neoplasm positive for myogenin and desmin that was compatible with cRMS. In the immunohistochemistry study, the neoplasm was positive for vimentin, myogenin, and desmin, as is characteristic of cRMS, and negative for synaptophysin and enolase, ruling out primitive neuroectodermal embriogenic tumor (PNET). Given a diagnosis of cRMS, a combined thoracoabdominal PET-CT scan was performed without finding other primary lesions and a bone marrow study was also performed without observing abnormalities. Consequently, the diagnosis was established as primary cRMS. DISCUSSION: Among the long-term sequelae of radiotherapy, neurocognitive disorders, brain disorders such as leukomalacia, vascular diseases, or secondary tumors, ranging from benign lesions such as meningiomas to more aggressive lesions such as ependymomas, which are high-grade gliomas, are described. In the brain MRI, our patient showed a radiotherapy-induced periventricular leukomalacia and a malignant lesion: a cRMS. The use of carmustine in this disease may facilitate local control.

Acute hemorrhage in a colloid cyst of the third ventricle: A rare cause of sudden deterioration.

BACKGROUND: Acute neurological deterioration and death in a patient harboring a colloid cyst of the third ventricle remains a poorly understood phenomenon. Sudden neurological derangement caused by spontaneous bleeding within a colloid cyst is a rare and potentially fatal event, usually requiring immediate diagnosis and emergency surgical treatment. CASE DESCRIPTION: A 47-year-old male presented with acute right-sided hemiparesis and speech impediment, followed by rapid deterioration of consciousness. Neuroimaging studies showed a rounded mass at the roof of the anterior third ventricle, causing biventricular hydrocephalus along with a left-sided basal ganglia hematoma. The lesion showed scattered foci of a recent hemorrhage which extended into the left lateral ventricle. Surgical treatment involved emergency external ventricular drainage followed by the prompt elective total resection of the lesion via a transcallosal route. Pathological findings confirmed the diagnosis of a colloid cyst with focal areas of vascular congestion and blood extravasation within its wall. CONCLUSIONS: Spontaneous bleeding into a colloid cyst of the third ventricle may cause acute obstructive hydrocephalus and intracranial hypertension due to rapid enlargement of the lesion. This event may account for the sudden neurological deterioration and/or death observed in a previously asymptomatic patient. The diagnosis of hemorrhagic phenomena within a colloid cyst represents a challenge due to the variable signal usually displayed by these lesions on computed tomography (CT) and magnetic resonance imaging (MRI). Emergency ventricular drainage followed by elective tumoral removal constitutes a valid and safe treatment strategy.