Infratentorial localisation of a dysembryoplastic neuroepithelial tumor. A case report

Neuroepithelial dysembryoplastic tumor (DNT) is usually considered as a supratentorial benign neoplasm. DNT of the posterior fossa is a very rare entity and only four previous cases were reported in the literature. We describe a case of a 26-Year-old woman presenting recurrent episodes of vertigo. Magnetic resonance imaging revealed four cystic lesions located in the cerebellum, hypointense on T1-weighted images and hyperintense on T2-weighted images, without gadolinium enhancement. After partial resection, histological examination showed small glial cells, oligodendrocytes-like, lying in an eosinophilic alveolar matrix with some floating neurons. Due to this specific glioneuronal element, the diagnosis of DNT was retained. We discuss the clinical and radiological particularities of this infratentorial location and compare our case with those previously described in the literature.     

Dysembryoplastic neuroepithelial tumors. Report of 8 cases including two with unusual localization

OBJECTIVES: Dysembryoplastic neuroepithelial tumors (DNTs) are usually located within the supratentorial cortex. We present a series of eight cases of DNTs including two cases with an extracortical location, one in the caudate nucleus, the other one expanded in the lateral ventricule, septum and fornix. An origin from secondary germinal layers, as previously suggested, can explain these extracortical locations. MATERIAL AND METHODS: Of the eight patients, seven had partial epileptic seizures and one intracranial hypertension. All patients underwent clinical examination, a computed tomographic (CT) scan, a magnetic resonance imaging (MRI) and a surgical removal of the lesion with histological examination. RESULTS: Clinical examination was normal except in the case with intracranial hypertension where a bilateral papillary oedema was found. In seven cases the CT scan showed a hypodense lesion of pseudocystic appearance. All lesions were hypointense on T1-weighted and hyperintense on T2-weighted MRI. Contrast enhancement was observed in two cases. The lesion was intracortical in six cases and extracortical in the remaining two: one in the head of the caudate nucleus and one in the trigonoseptal region. Histological examination identified an appearance of DNT with a specific glioneuronal element in six cases. CONCLUSION: The diagnosis of DNT can be suspected before histological examination on radiological features, chiefly because the tumor is located in the supratentorial cortex. However, extracortical locations do exist, even if unusual. As DNTs are always benign, knowledge and accurate diagnosis of these atypical cases are mandatory in order to avoid useless and even deleterious additional treatments, such as radiotherapy.     

Operative case of eosinophilic granuloma of the skull with dural invasion

Eosinophilic granuloma is the localized form of Langerhans' cell histiocytosis. There are several reports of magnetic resonance (MR) imaging of eosinophilic granuloma of the skull, however there are few reports about dural enhancement. We report an operative case of eosinophilic granuloma of the skull with dural invasion. A 42-year old man was admitted to our hospital. He was neurologically intact and there were no other osseous or soft tissue lesions. CT showed an osteolytic lesion in the left parietal bone. MR images showed the lesion as isointense on T1-weighted, and high intense on T2-weighted images. T1-weighted images with Gd-DTPA demonstrated the mass which was enhanced with dural surface and subgaleal tissue. The angiogram demonstrated a tumor stain fed by the left occipital artery. Bone scintigraphy demonstrated a solitary lesion showing peripheral uptake with a central defect. The patient underwent craniectomy with removal of the dura and a subgaleal lesion. Histological examination revealed characteristic eosinophilic granuloma with dural invasion. No recurrence of the lesion was demonstrated 6 months after surgery.     

Choroid plexus metastasis of lung carcinoma--case report.

Metastatic tumors in the choroid plexus are generally considered to be very rare. The authors present a case of lung large cell carcinoma with a single metastatic tumor in the choroid plexus of the lateral ventricle trigone. Precontrast computed tomographic (CT) scans showed an isodensity mass with extensive peritumoral edema, which was considerably enhanced on the postcontrast CT scans. Magnetic resonance (MR) images demonstrated the mass as a low-intensity area on the T1-weighted image and an iso-intensity area on the T2-weighted image. The tumor was clearly differentiated from the peritumoral edema by both CT and MR imaging. The diagnosis was confirmed by surgery.     

Colloid (enterogenous) cyst in the frontal lobe

A 60-year-old man presented with a left frontal mass lesion incidentally detected at a health check without apparent symptoms. Computed tomography revealed the lesion as homogeneous high density and magnetic resonance (MR) imaging showed the lesion as hyperintense on T(1)-weighted images, isointense on T(2)-weighted images, and hypointense on diffusion-weighted images. T(1)-weighted MR images with gadolinium showed no enhancement of the mass lesion. Cerebral angiography revealed an avascular area around the left frontal lesion. Total removal of the lesion was achieved through a craniotomy without complications. Histological, immunohistochemical, and electron microscopy examinations established the definite diagnosis of colloid cyst.     

Spontaneous regression of an asymptomatic meningioma associated with discontinuation of progesterone agonist administration

An 80-year-old male visited the hospital as an outpatient with a head injury sustained in a traffic accident. Brain computed tomography incidentally revealed a left frontal lobe tumor measuring 5 cm in a diameter. The patient had a history of taking chlormadinone acetate (a progesterone agonist) prescribed several years previously as treatment for benign prostatic hypertrophy. The tumor was seen as an isointense lesion on T(1)-weighted magnetic resonance (MR) images with enhancement by gadolinium, and as a heterogeneously hyperintense mass on T(2)-weighted MR images. The tentative diagnosis was left frontal meningioma attached to the sphenoid ridge or sphenoid plane. The patient was managed conservatively because of his advanced age and no symptoms or progression were observed during a 9-month follow-up period. The medication for benign prostatic hypertrophy was changed from chlormadinone acetate to naftopidil (an alpha-2-blocker) about 9 months after his first presentation. The patient presented again 2 years later complaining of dizziness. Computed tomography and MR imaging performed at this time revealed remarkable regression of the tumor. The signal intensity change with regression of the tumor on T(2)-weighted images was observed as a hypointense lesion. Thus, we wish to emphasize that treatment of meningiomas, especially those diagnosed incidentally, must be based on a thorough consideration of any history of hormonal therapy with prostate disease.     

Hemangioblastoma of the third ventricle

A third ventricle tumor, in addition to a recurrent cerebellar hemangioblastoma, was found in a 47-year-old woman on follow-up magnetic resonance imaging (MRI) 5 years after operation of the cerebellar tumor. On MRI, the tumor was hypo- to isointense on T1-weighted images and hyperintense on T2-weighted images compared with the normal gray matter, and was strongly enhanced with gadolinium. The tumor was first treated with fractionated conventional external-beam radiation (5120 cGy in 16 fractions over a 4-week period), resulting in a slight decrease in size of the tumor. For a definite diagnosis and mass reduction, surgery was performed using an interhemispheric translamina terminalis approach, resulting in a partial removal of the tumor due to profuse bleeding. Histological diagnosis was hemangioblastoma. Hemangioblastomas of the third ventricle are extremely rare and have not been specifically discussed. We describe the detailed clinicopathological features of the present case together with the possible explanation for the development of this tumor in this rare location. Received: 28 November 1997 / Accepted: 19 August 1998     

Central neurocytoma: report of a case

Central neurocytoma is a rare intraventricular tumor recently accepted as a clinicopathological entity. A 21-year-old female was admitted with three-year history of episodic headaches and vomiting, and with rapid deterioration of her left vision over two weeks prior to admission. Computed tomography (CT) scan revealed a marked hydrocephalus and an isodense, mildly enhancing mass in the left lateral ventricle. On magnetic resonance imaging (MRI) scan, T1-weighted images revealed an intraventricular mass of slightly high intensity signal, which contained areas of low intensity signal representing multiple intratumoral cysts. The tumor showed a minimal enhancement with Gd-DTPA. A diagnosis of central neurocytoma was confirmed by an electron-microscopic study of a surgical specimen; there were numerous neuronal cell processes containing microtubules and dense-core vesicles, and a few small intercellular junctions were also identified.     

Giant cell reparative granuloma of the temporal bone: neuroradiological and immunohistochemical findings

A 38-year-old man presented with a giant cell reparative granuloma (GCRG) of the left temporal bone. Computed tomography showed a osteolytic middle cranial mass lesion. Magnetic resonance (MR) imaging showed the lesion as low intensity with heterogeneous enhancement by gadolinium on the T1-weighted images, and extremely low intensity on the T2-weighted images. Angiography showed the lesion as highly vascular and fed by branches of the left external carotid artery. After preoperative embolization, gross total removal of the tumor was performed. The postoperative course was uneventful and no evidence of recurrence has been found for more than 4 years. Histological examination revealed GCRG with multinucleated giant cells in the fibrous background, abundant collagen bundles, hemosiderin deposits, and trabeculae of reactive bone. Some of the mononuclear stromal cells and almost all of the giant cells were positive for CD68, suggesting histiocytic differentiation. These histological features reflect the marked decrease in signal intensity on T2-weighted MR images.     

Vermian epidermal cyst developing in the fourth ventricle. A case report

A 34-year-old man presented with recent severe headache. Neurological examination found gait disturbance and a static cerebellar syndrome. The CT scan showed a tumor located in the fourth ventricle and which presented with a density close to that of the cerebellar parenchyma, without contrast enhancement, associated with an enlargement of the third and the lateral ventricles. MRI showed that the tumor had an heterogeneous hyposignal on T1-weighted images and an hypersignal on T2-weighted images, without associated edema; the roof of the fourth ventricle was displaced upward and the brain stem forward. At operation, an encapsulated epidermal cyst, developed from the cerebellar vermis, without attachment to the floor of the fourth ventricle, was totally removed. Epidermal cysts of the fourth ventricle are unusual lesions; their capsule often adhere to the floor and cannot be totally removed. Those developed from the cerebellar vermis seem to be rarer. With the use of MRI, their true origin could be suspected. In these cases, the cysts can be totally removed, reducing the risk of recurrence     

Supratentorial ectopic ependymoma: a case report

Ependymomas usually arise from the ventricular surface and approximately two-thirds of them are infratentorial. We present an unusual case of supratentorial ependymoma located in the parietal parenchyma and exhibiting no continuity with the ventricular system. On March 30, 1998, a 63-year-old woman was admitted to our neurosurgical service because of a sudden consciousness loss attack two weeks before. On admission, neurological examination revealed no abnormal findings. Computerized tomography (CT) revealed a mass lesion of the parietal lobe which was enhanced homogeneously. Magnetic resonance imaging (MRI) also showed the mass of the parietal lobe which was iso-intense on T1-weighted images, iso and high intense on T2-weighted images and homogeneously enhanced by administration of Gd-DTPA. In the angiography, left carotid angiograms showed a tumor stain. On February 26, 1998, total removal of the tumor was performed using stereotactic craniotomy with neuronavigator and intraoperative echography. After surgery, focal radiation therapy (56Gy) was carried out. The pathological diagnosis was cellular ependymoma with partial clear cell components. Several kinds of tumor may occur in the cerebral parenchyma. We conclude, however, that ependymoma has to be included in the differential diagnosis when the tumor location is distant from the ventricles.     

Cavernous angioma in the fourth ventricular floor--case report.

A rare case of cavernous angioma located in the fourth ventricular floor occurred in a 44-year-old female complaining of occipital headache, vomiting, diplopia, and dysarthria. Computed tomographic scans demonstrated a high-density area in the fourth ventricle and slight hydrocephalus. Magnetic resonance (MR) imaging showed a mixed intensity mass on T2-weighted images and high- or isointensity regions on T1-weighted images. The tumor was totally removed and histologically diagnosed as cavernous angioma. Postoperatively, ataxic gait, nausea, and vomiting disappeared gradually. MR imaging was useful to accurately evaluate the anatomic relationship between the lesion and the brainstem.     

Symptomatic subependymoma: a clinicopathological and flow cytometric study

Twenty-one intracranial subependymomas were reviewed with regard to presentation, diagnosis, operative findings, and long-term follow-up data. The histopathological features were critically reviewed, and deoxyribunucleic acid analysis was performed by flow cytometry. The patients' mean age was 48.5 years (range 32 to 72 years). In 14 cases the tumor was located in the fourth ventricle, in six within a lateral ventricle, and in one in the third ventricle with extension into the lateral ventricle. Radiographic characteristics included isodensity with minimal enhancement on computerized tomography, frequent dystrophic calcification, and isointensity on T1-weighted or slight hyperintensity on T2-weighted magnetic resonance images. The predominant histological features in all cases were those of classic subependymoma. Nonetheless, pathological examination showed a minor (less than 20%) ependymoma component in five cases, significant cytological atypia in seven, mitoses in 11, endothelial prominence in four, and focal hemorrhage-associated necrosis in two. Flow cytometry revealed a diploid pattern in 12 patients, tetraploidy in two, and aneuploidy in one. Two patients died in the perioperative period. Of the remaining 19, 12 underwent gross total resection (two of whom received postoperative irradiation) and seven underwent subtotal resection (five of whom received irradiation). None of the 12 non-irradiated patients developed tumor progression or died of direct tumor-related causes. Of the seven irradiated patients, follow-up imaging studies demonstrated their tumors to be radioresponsive, particularly with doses of 5000 cGy or greater. Despite the presence of cytological atypia and mitotic activity in the majority of cases, the prognostic effects of such factors as tumor location and the extent of surgical resection outweighed those of the standard histopathological parameters. Routine postoperative irradiation is not recommended, but should be reserved for cases with a symptomatic residual or recurrent subependymomas following surgery.     

Capillary hemangioma of the spinal cord. A new case

A 49-year-old man presented with a 8-month history of gait and sphincter disturbances. Examination revealed a spastic paraplegia predominant on the left limb, associated with decreased tactile sensitivity below T10. MRI showed a right posterolateral intramedullary lesion with an isosignal on T1-weighted images and a mild hypersignal on T2-weighted images, with an intense contrast enhancement; the spinal cord presented with an hypersignal on T2-weighted images. At operation, a vascular tumor presented at the spinal cord surface, was well demarcated from the parenchyma and was easily removed. Microscopic examination showed a capillary hemangioma. Three months later the patient exhibited a motor improvement with a right spasticity, deficits in proprioception, without sphincter abnormalities. A new MRI showed the disappearance of the hemangioma and of the preoperative spinal cord hypersignal. Capillary hemangiomas are unusual on nerves or roots. Cases found in the spinal cord are extremely rare: to our knowledge, 5 cases have been reported. On MRI, they are easily distinguished from cavernous hemangiomas, but microscopic examination is necessary to distinguish them from hemangioreticulomas. The postoperative prognosis is generally good. However, a report of a multiple location case, on roots and spinal cord, suggests the need for long follow-up.     

Neurocytoma manifesting as intraventricular hemorrhage--case report

A 43-year-old man presented with a neurocytoma manifesting as severe headache and disturbance of consciousness. Computed tomography revealed intraventricular hemorrhage, and a small mass lesion with calcification on the wall of the left lateral ventricle. The lesion appeared as mixed intensity regions on both T(1)- and T(2)-weighted magnetic resonance imaging, and heterogeneous enhancement with gadolinium-diethylenetriaminepenta-acetic acid. Angiography showed the pooling sign near the calcification in the late venous phase. Neurologically, amnestic syndrome was demonstrated in the subacute phase. Gross total removal of the lesion was performed through a transcallosal approach. His transient memory disturbance resolved. The histological diagnosis was neurocytoma. Intraventricular hemorrhage is rare as the initial presentation of neurocytoma. Surgery should avoid fornix injury and the risk of permanent memory disturbance.     

Osteoblastoma of the temporal bone: a case report

Benign osteoblastoma is an unusual primary bone tumor. It affects usually long bones or the vertebral column. Osteoblastoma affecting the calvarium is extremely rare. A 23-year-old man presented with a two-month history of swelling and tenderness in the right temporal region. Computed tomography revealed an expansile, lytic lesion in the left temporal bone. T1- and T2-weighted magnetic resonance (MR) images demonstrated an isointense lesion in the temporal bone. After gadolinium DTPA injection, MR images revealed dense enhancement. The histopathological findings proved that the lesion was a benign osteoblastoma. To date, very few cases of the benign osteoblastoma arising in the calvarium have been reported in the literature. We discuss diagnostic and management aspects of this uncommon tumor.     

Atypical growth pattern of a meningioma in an adult

A 49-year-old woman presented with a rare atypical growth pattern of meningioma without evidence of dural attachment manifesting as chronic headache associated with transient paresthesia and left motor disorders. On admission, neurological examination showed no abnormalities. Magnetic resonance (MR) imaging revealed a right temporo-parieto-occipital lesion, which appeared to involve the subdural space and filling the cortical sulci. The lesion caused peritumoral white matter edema. The tumor appeared hypointense on T(1)-weighted and hyperintense on T(2)-weighted MR images, with homogeneous enhancement after contrast administration. A biopsy of the lesion was performed. Histological examination indicated that the lesion was a meningioma. Intraparenchymal meningiomas should be considered in the differential diagnosis of intraaxial lesions in patients of any age.     

Cavernous angioma of the internal acoustic meatus--case report

A 39-year-old female presented with an intrameatal cavernous angioma manifesting as hearing loss and tinnitus in the right ear which progressed over 8 months. Magnetic resonance (MR) images revealed an intrameatal lesion as ultra-high intensity, nearly as bright as cerebrospinal fluid, on the T2-weighted images, and isointensity on the T1-weighted images. Computed tomography (CT) showed the mass accompanied by stippled patterns of calcification. The patient underwent surgery under a diagnosis of calcified acoustic neurinoma. Histological studies were compatible with cavernous angioma. Intrameatal cavernous angioma is a rare disease which requires differential diagnosis from the more common neurinoma or meningioma in this location. Intrameatal lesion with ultra-high intensity on T2-weighted MR imaging and stippled patterns of calcification on CT is more likely to be cavernous angioma than acoustic neurinoma. These neuroimaging features are important information in deciding the treatment strategy.     

Contrast-enhanced magnetic resonance imaging of malignant granular cell tumor with pathological correlation: a case report

This report presents a case of malignant granular cell tumor in the deltoid muscle and emphasizes the correlation between magnetic resonance (MR) images and pathological findings. A 71-year-old woman developed an elastic hard mass at the left shoulder. MR images revealed a soft tissue tumor with a maximum diameter of 5cm and low signal intensity on both T1- and T2-weighted images. The lesion with decreased signal intensity on all the images correlated with marked fibrosis mimicking desmoid tumor. Contrast-enhanced MR images provided useful information regarding the choice of biopsy site.     

Experience of thoracoscopic extirpation of intrapulmonary lymphangioma

We report a 59-year-old woman who underwent thoracoscopic extirpation of the intrapulmonary cystic lymphangioma which was located in the subpleural space of the left upper lobe. A chest X-ray showed a solitary round nodule in the left pulmonary hilum. A computed tomography scan revealed a mass shadow at the interlobar region surrounding the interlobar pulmonary artery. A round nodule was recognized as low signal intensity on T1-weighted images by magnetic resonance imaging. There was biphasic signal intensity on T2-weighted images as well. Radiologically, we diagnosed this lesion as a benign cystic tumor in the lung. Thoracoscopic observation revealed a cystic lesion just beneath the visceral pleura of the upper lobe adjacent to the interlobular pulmonary artery. As this suggested a benign bronchogenic cyst, we performed extirpation of the cyst under thoracoscopy. After this operation, the cyst was diagnosed as an intrapulmonary cystic lymphangioma pathologically.