Pigmented hepatocellular adenoma: report of a case

Hepatocellular adenoma is a rare, benign neoplasm that is related to the use of contraceptives or androgenic-anabolic steroids. A 51-year-old man with no history of steroid use was found to have a liver tumor. Plain computed tomography showed a high-density tumor that was enhanced in the arterial phase, and the enhancement was prolonged in the delayed phase. Magnetic resonance imaging showed that the tumor was hyperintense on in- and opposed-phase T1-weighted gradient recalled echo images and hyperintense on T1-weighted spin echo images. A partial hepatic resection was performed. A histological examination revealed normal hepatocyte-like tumor cells, composed of abundant dark brown granules of Dubin-Johnson-like pigment, which stained positively for Masson-Fontana stain. The tumor was diagnosed to be a very rare hepatocellular adenoma with the deposition of Dubin-Johnson-like pigment.     

Magnetic resonance imaging of a fat embolism of the brain: case report

A 22-year-old man developed fat embolism syndrome. Although a computed tomographic (CT) scan of the brain showed nothing abnormal, a magnetic resonance imaging scan detected scattered spotty areas of low intensity on T1-weighted images and of high intensity on T2-weighted images. Magnetic resonance imaging is thought to be more sensitive than computed tomography in detecting cerebral fat embolism syndrome and correlates well with the clinical course.     

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.     

Intracranial epidermoid tumor with changes in signal intensity on magnetic resonance imaging because of non-hemorrhagic pathology: case report

A 61-year-old woman presented an intracranial epidermoid tumor manifesting as dizziness and right facial hypesthesia. Magnetic resonance (MR) imaging revealed a well-defined lobulated mass in the right cerebellopontine angle as nearly isointense to the cerebrospinal fluid (CSF) on both T(1)- and T(2)-weighted images but inhomogeneously hyperintense on fluid-attenuated inversion recovery images. MR imaging performed 1 year later revealed that the tumor had significantly enlarged, and now appeared hyperintense to the CSF on T(1)- and T(2)-weighted images. The lesion was confirmed at surgery to be an epidermoid tumor filled with xanthochromic fluid. Histological examination found no evidence of hemorrhage in the resected tumor, so the changes in the MR imaging signal intensity were attributed to changes in the protein concentration of the intratumoral fluid, accumulation of debris, or some other non-hemorrhagic process.     

Neuroimaging of cerebellar liponeurocytoma. Case report.

Cerebellar liponeurocytoma is a newly recognized, rare clinicopathological entity. It manifests with posterior fossa symptoms in adults and is characterized histopathologically by advanced neuronal and focal lipomatous differentiation with a low level of mitotic activity. The authors analyzed the computerized tomography (CT) and magnetic resonance (MR) imaging findings in two patients with histopathologically proven cerebellar liponeurocytomas and review the literature. Cerebellar liponeurocytoma may be suspected on the basis of neuroimaging findings that demonstrate an intraaxial neoplasm with the propensity for exophytic growth into the adjacent subarachnoid spaces. On CT scans, the tumor commonly presents as a hypointense mass with intermingled areas exhibiting the attenuation values of fatty tissue. On T1-weighted MR images, the tumor is hypointense with scattered foci of hyperintense signal and displays moderate contrast enhancement. On T1-weighted MR images, the tumor is slightly hyperintense to cortex, and edema is usually absent. Areas of fat density as assessed on CT scans and of T1 hyperintensity seen on MR images help to distinguish this rare neoplasm from the more common adult medulloblastomas or ependymomas. The available follow-up data indicate a favorable clinical prognosis; therefore, knowledge and precise characterization of this tumor is important to avoid unnecessary adjuvant radio- or chemotherapy.     

Supratentorial convexity leptomeningeal schwannoma: case report

OBJECTIVE AND IMPORTANCE: Leptomeningeal schwannomas are very rare; to our knowledge, only one case has been previously reported. The possible histogenesis and differential diagnosis of intracranial schwannomas not related to cranial nerves are discussed. CLINICAL PRESENTATION: A 53-year-old man presented with a sudden onset of seizures. Computed tomographic scans revealed a small hypodense mass in the peripheral aspect of the left frontal lobe. The mass was hypointense on T1-weighted and hyperintense on T2-weighted magnetic resonance imaging scans, with ring enhancement after contrast medium administration. INTERVENTION: A craniotomy was performed for total removal of the tumor, revealing a well-demarcated, firm, spherical tumor beneath the dura. The tumor was easily separated from the brain. Histologically, the tumor was observed to be within the subarachnoid space, intimately attached to the pia mater. The adjacent brain tissue and dura mater were free of tumor cells. The histological diagnosis was schwannoma. CONCLUSION: Computed tomographic and magnetic resonance imaging findings in our case were consistent with those for a schwannoma, although the subarachnoid space is an extremely rare location for schwannomas. We emphasize that schwannomas may arise in the subarachnoid space.     

A periosteal chondroma in the lumbar spinal canal. Case report

Periosteal chondromas located in the spine are rare. The authors document a case of periosteal chondroma in the lumbar spinal canal of a 77-year-old man. The patient had severe pain in his right leg and used a wheelchair because of weakness in both legs. Magnetic resonance imaging revealed a round tumor that was hypo- or isointense on T1-weighted images and uniformly hyperintense on T2-weighted images. Administration of gadolinium-diethylenetriamine pentaacetic acid resulted in margin enhancement on T1-weighted images. During the operation, a round tumor 1.5 cm in diameter was found on the surface of the anterior wall of the L-3 lamina. Histological examination revealed that the tumor consisted of chondroid tissue with typical chondrocytes, indicating that it was a periosteal chondroma.     

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     

Reversible posterior leukoencephalopathy in a patient with Wegener granulomatosis

A 14-year-old girl with rapidly progressive glomerulonephritis was transferred to our hospital because of acute renal failure. A diagnosis of Wegener granulomatosis was made according to the symptom triad of a renal biopsy demonstrating crescentic glomerulonephritis, severe sinusitis, and serological findings of raised proteinase 3 anti-neutrophil cytoplasmic antibody level. In spite of combination therapy with methylprednisolone, cyclophosphamide, and plasma exchange, her renal function gradually deteriorated. Thereafter, she suffered a severe headache and generalized seizures. Brain computed tomography (CT) scan revealed bilateral low-density areas in the parieto-occipital lobes. Magnetic resonance imaging (MRI) disclosed a high-intensity area on T2-weighted images and a low-signal intensity area on T1-weighted images in the same lesion. Follow-up brain CT scan 3 weeks and MRI 2 months after the first studies showed complete resolution of the abnormal lesions, which indicated reversible posterior leukoencephalopathy syndrome. In addition to renal failure, hypertension, and cyclophoshamide, the primary disease may have played a role in the development of this uncommon syndrome in our patient.     

Diffuse cerebrospinal gliomatosis. Case report]

A 65-year-old male was admitted with memory and gait disturbance. A computed tomography (CT) scan showed bilateral, diffuse, low-density areas with two round, slightly enhanced masses. T1-weighted magnetic resonance image revealed a low-intensity area in the left paraventricular region, which converted to increased signal intensity, extending to the right paraventricular region through the splenium, on T2-weighted images. The tumor was diagnosed as glioblastoma multiforme after needle biopsy and treated by irradiation and chemotherapy. Seven months after admission, a CT scan revealed subependymal infiltration of the tumor with spotty calcification. He died of respiratory complications 11 months after the onset of symptoms. The autopsy showed brain swelling with flattened gyri. Horizontal sections of the brain showed diffuse enlargement of the white matter and basal ganglia with scattered hemorrhage and necrosis. Microscopically, the lesion was far more extensive and diffuse than was suspected from gross examination. Wide glial tumor cell infiltration was observed in the cerebral hemispheres, basal ganglia, brainstem, cerebellum, and even the cervical spinal cord with minimum destruction of the pre-existing architecture. Calcification was found around the thrombosed vessels and necrotic lesions. The clinical diagnosis and histological features of gliomatosis cerebri are discussed with reference to reported cases.     

Pineoblastoma showing unusual ventricular extension in a young adult--case report.

A 19-year-old male presented with a 4-week history of headache. Neurological examination showed bilateral papilledema. Computed tomography revealed a pineal region mass with remarkable obstructive hydrocephalus. Magnetic resonance imaging showed a pineal region tumor continuously invading through the tectum into the cerebral aqueduct and the fourth ventricle with the preservation of the adjacent structures. The tumor appeared an iso- to hypointense mass on T1-weighted images, a heterogeneous iso- to hyperintense mass on T2-weighted images, and a heterogeneously enhanced mass after administration of contrast medium. Histological examination after endoscopic biopsy confirmed that the tumor was a pineoblastoma. Radiotherapy was given to the whole brain and the spinal cord, and magnetic resonance imaging showed complete remission of the tumor. Pineoblastomas are highly malignant tumors with seeding potential through the neighboring ventricle or along the meninges, and this type of tumor becomes larger with local extension. We found no previous reports of the continuous extension into the fourth ventricle. The present case showed ventricular extension with minimal mass effect to adjacent structures, and did not disturb ventricular configuration. According to the unusual finding of ventricular extension, this rare case of pineoblastoma requires adjuvant chemotherapy.     

Reversible posterior leukoencephalopathy syndrome accompanied by HELLP syndrome and eclampsia: a case report]

We report a case of reversible posterior leukoencephalopathy syndrome accompanied by HELLP syndrome and eclampsia. A 30-year-old woman complained of diminution of visual acuity and eclampsia. Laboratory data revealed hemolysis, elevated liver enzyme and low platelets. CT showed low density areas in the bilateral occipital cortex. T1-weighted images showed a low signal intensity and T2-weighted images showed a high signal intensity in the occipital cortex bilaterally. Magnetic resonance angiography showed stenotic change in the intracranial artery. An operation was performed and significant improvement was seen in her visual function and MRI and MRA returned to normal on a month after operation. The mechanism of a reversible posterior leukoencephalopathy syndrome was discussed.     

Application of three-tesla magnetic resonance imaging for diagnosis and surgery of sellar lesions

OBJECT: The aim of this study was to determine the value of high-field magnetic resonance (MR) imaging for diagnosis and surgery of sellar lesions. METHODS: High-field MR images were obtained using a 3-tesla unit with emphasis on sellar and parasellar structures in 21 patients preoperatively to delineate endo-, supra-, and parasellar anatomical structures. Special attention was given to the medial border of the cavernous sinus and possible invasion of a sellar tumor therein, and to assessing the application of high-resolution images during intraoperative neuronavigation. The 3-tesla MR images were compared with the standard MR images already obtained and with intraoperative findings. Anatomical structures were studied in all 42 cavernous sinuses; in 32 of them comparisons with intraoperative findings were possible. The medial cavernous sinus border was rated intact in 53% on standard MR images, in 72% on 3-tesla MR images, and in 81% intraoperatively. With a positive correlation to surgical findings on 84% of 3-tesla MR images compared with 59% of standard MR images, a sensitivity of 83% compared with 67%, and a specificity of 84% compared with 58% (p = 0.016, McNemar test), 3-tesla MR imaging was superior for predicting tumor invasion through the medial cavernous sinus border. Although no difference was noted in delineation of the medial, superior, and inferior compartments, there was a better delineation of the lateral cavernous sinus compartment with 3-tesla MR imaging. This compartment was clearly visible on 40 sides (95%) on 3-tesla MR images compared with 34 sides (81%) on standard MR images. Identification of the cavernous sinus segments of the third, fourth, fifth (V1 and V2), and sixth cranial nerves was improved using high-resolution 3-tesla imaging compared with standard MR imaging. A mean of four cranial nerves was found as hypointense spots (range two-five spots) on 3-tesla MR imaging compared with a mean of three (range zero-four spots) on standard MR imaging. After addition of contrast agents, the anterior pituitary gland was found to be highly intense on 78% of T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) 3-tesla MR images compared with 73% of standard T1-weighted MR images. The optochiasmatic system displayed increased intensity on pre-contrast T1-weighted MPRAGE 3-tesla compared with standard T1-weighted MR images; it was hyperintense on 76% of 3-tesla compared with 15% of standard MR images, which was helpful for its delineation from suprasellar pituitary and tumor structures. Intraoperative navigation guided by fusion of 3-tesla MR images and computerized tomography (CT) scans was performed in seven patients. Whereas CT scanning was used during the transsphenoidal approach to depict the nasal bone structures, 3-tesla MR imaging was particularly useful for the visualization of parasellar tumor extension during microsurgical and/or endoscopic resection. CONCLUSIONS: Due to its higher resolution, 3-tesla MR imaging was found to be superior to standard MR imaging for the delineation of parasellar anatomy and tumor infiltration of the cavernous sinus, and this modality provided improved imaging for intraoperative navigation.     

A multicentric glioma presenting different pathological appearances: a case report

We report a multicentric glioma case which revealed different pathological appearances. A 45-year-old male had been admitted to our hospital complaining of an attack of transient sudden aphasia. On magnetic resonance imaging (MRI), T1-weighted images revealed a low intensity and T2-weighted images demonstrated a homogeneous high intensity abnormal mass in the frontal lobe, which was not enhanced with gadolinium. Removal of the tumor was performed through a right frontal transcortical approach in March, 2002. Histological diagnosis was gemistocytic astrocytoma. The patient's condition was uneventful and postoperative MRI revealed a marked decrease in the volume of the tumor. A total of 54 Gy radiation to the brain in the locality was performed. Four months after the initial surgery, the patient suffered from incomplete right hemiparesis. MRI showed a left parietal abnormal mass which had a ring formation enhancement after gadolinium administration. This Neuro-radiological examination demonstrated complete independence from the initial right frontal tumor. A second surgery which was concerned with cyst aspiration was carried out on August 10, 2002. During the next month, a third operation for partial removal of a left parietal abnormal mass was performed. Histological diagnosis was anaplastic astrocytoma. The right frontal and left parietal tumors revealed neither continuous relation suggesting intracerebral invasion, nor dissemination through the subarachnoid space nor intracerebral metastasis. Our case was diagnosed as multicentric glioma with different pathological appearances, of which only 9 cases have been reported previously.     

Intrahepatic cholangiocarcinoma with extensive sarcomatous change: Report of a case

A 77-year-old woman was admitted to our hospital with severe upper abdominal pain. Ultrasonography showed a well-defined hypoechoic mass with heterogeneity in the left lobe of the liver, and computed tomography demonstrated a low-density mass with enhanced peripheral areas. Magnetic resonance imaging revealed a mass with iso- to low signal intensity on T1-weighted images (WI) and heterogeneous high and low signal intensity on T2 WI. The tumor was found to be hypovascular by angiography. During 5 months of observation, the tumor increased in size, which strongly suggested malignancy. A laparotomy was performed under the provisional diagnosis of a neoplasm other than hepatocellular carcinoma, revealing that the hepatic mass had invaded the gastric wall. Therefore, a left hepatic lobectomy with dissection of the lymph nodes and hemigastrectomy was carried out. Histologically, the tumor was found to be composed of a large amount of sarcomatous elements and a small amount of adenocarcinomatous elements, both of which were partly intermingled. Immunohistochemically, the sarcomatous element demonstrated the features of malignant fibrous histiocytoma (MFH). Thus, a diagnosis of intrahepatic cholangiocarcinoma with MFH-like sarcomatous change was confirmed.     

Retroperitoneal fibrosarcoma with myxoid matrix: a case report

A 54-year-old male visited a local physician with right dorsolumbar pain as the chief complaint. Ultrasonography revealed a tumor mass 13 cm in diameter at the lower part of the liver, and the patient was referred to our hospital. On abdominal computed tomography, uneven contrast-enhanced effects were recognized in the tumor. On magnetic rescmance imaging studies, T1-weighted images showed a hypoechoic pattern from the kidney and a weak hyperechoic pattern from the muscle. T2-weighted images showed uneven hyperecoic patterns. Uneven contrast-enhanced effects were recognized inside and on the margin of the tumor. A diagnosis of retroperitoneal tumor was made, and surgery was performed. Histopathological examination revealed a fascicular alignment of spindle cells in the area in which the myxoid matrix is seen. On the immunological special test, only vimentin was positive, which led to the diagnosis of fibrosarcoma. Fibrosarcoma originating from retroperitoneal tumor is relatively rare.     

The hPMS2 exon 5 mutation and malignant glioma. Case report

Patients with Turcot syndrome (TS) are predisposed to colon tumors and primary brain tumors, typically glioblastomas or medulloblastomas. The authors describe a patient with TS featuring a known germline mutation of exon 5 of the hPMS2 mismatch repair gene who developed two metachronous glioblastomas, both with distinct oligodendroglial features. Molecular genetic analysis revealed allelic loss of chromosome 19q in the patient's second tumor but no allelic loss of chromosome 1p. Prominent microsatellite instability was also found in this tumor, consistent with a germline mismatch repair defect. Because this patient had an unusual underlying condition and his tumor had a unique histological appearance for TS, it was hypothesized that this genetic defect may predispose to malignant gliomas with oligodendroglial features. The authors therefore evaluated whether sporadic glioblastomas and oligodendrogliomas undergo mutations of this region of the hPMS2 gene. However, single-strand conformation polymorphism analysis of hPMS2 exon 5 failed to reveal mutations in 20 sporadic glioblastomas and 16 sporadic oligodendroglial gliomas. Thus, although it is possible that the germline hPMS2 exon 5 mutation may predispose to glioblastomas with an oligodendroglial component, the same genetic defect is not commonly involved in sporadic oligodendrogliomas or glioblastomas.     

Macrocystic serous cystadenoma of the pancreas

We report a 47-year-old woman with macrocystic serous cystadenoma of the pancreas. She had no past history of abdominal surgery, instrumentation, or trauma. Ultrasonography and computed tomography revealed a unilocular cyst in the body of the pancreas. On magnetic resonance imaging, the cyst showed heterogeneous signal intensity on T1-weighted images, and was homogeneously hyperintense and oligolocular is on T2-weighted images. A preoperative diagnosis of mucinous cystic neoplasm of the pancreas was made, and distal pancreatectomy was performed. The resected oligolocular cyst was 5.0 × 4.5 × 3.0 cm and was lined with a single layer of cuboidal epithelium similar to that seen in microcystic serous cystadenomas. Abundant glycogen was demonstrated within the epithelial cells, as assessed by periodic acid-Schiff (PAS) staining with and without diastase digestion. The cyst exhibited a gross appearance distinct from that of typical microcystic adenomas, resulting in diagnostic difficulties for the radiologists and surgeon involved in the patient's care. Received for publication on May 20, 1999; accepted on Sept. 1, 1999     

Cervical spine chondroma arising from C5 right hemilamina: a rare cause of spinal cord compression. Case report and review of the literature

Chondromas are rare primary spine tumors. Only 12 cases of chondromas located in the cervical spine have been reported in the literature up to now. The authors report a case of a cervical periosteal chondroma in a 38-year-old man presenting with neck pain and a syndrome of spinal cord compression. Magnetic resonance imaging revealed a lesion that was hypo- or isointense on T1-weighted images and iso-hyperintense on T2-weighted images. Administration of Gd-DPTA resulted in margin enhancement on T1-weighted images. CT scans revealed a hyperdense calcified lesion arising from the internal surface of C5 right hemi-lamina. The patient underwent a right C5 hemi-laminectomy, with complete en-bloc removal of the lesion. The authors emphasize that early identification of the initial lesion should be coupled with total surgical resection, as a definitive treatment, in order to prevent malignant transformation.     

Chordoid meningioma--case report

A 69-year-old female presented with a de novo lesion detected incidentally. Computed tomography demonstrated an isodense mass in the left parietal convexity with peritumoral edema, with homogeneous enhancement by contrast medium. Magnetic resonance imaging showed the left parietal convexity tumor as isointense on T(1)-weighted imaging and homogeneously hyperintense on T(2)-weighted imaging, with homogeneous enhancement and dural tail sign after intravenous administration of gadolinium-diethylenetriaminepenta-acetic acid. The tumor was totally removed. The histological diagnosis was chordoid meningioma. Combined immunohistochemical staining was helpful to differentiate chordoid meningioma from other chordoid neoplasm.