Advanced MR imaging in Lhermitte-Duclos disease: moving closer to pathology and pathophysiology

INTRODUCTION

Lhermitte-Duclos disease (LDD, dysplastic gangliocytoma) is an extremely rare cerebellar lesion of uncertain etiology. The debate as to whether it constitutes a neoplastic, malformative, or hamartomatous lesion is still continuing. In this report we explore the usefulness of susceptibility-weighted imaging (SWI), diffusion weighted imaging (DWI), perfusion imaging, and chemical shift imaging (CSI) in demonstrating the pathology and pathophysiology in two patients with LDD.

METHODS

MR imaging of the brain and the cervicodorsal spine was performed on a 1.5-T scanner in a 47-year-old woman presenting with numbness and paresthesia of both upper and lower limbs, and in a 17-year-old male with right frontal headache associated with neck pain.

RESULTS

Routine imaging in the first patient showed a left-side cerebellar mass with characteristic 'tiger-striped' thick folia associated with Chiari I malformation, tonsillar herniation and cervicodorsal syringomyelia and in the second patient a right cerebellar mass with similar findings. The SWI demonstrated the characteristic deep running veins between the folia, which is thought to be the cause for vascular contrast enhancement. Diffusion showed a T2 shine-through effect with mild increased diffusivity, and perfusion showed increase in relative cerebral blood volume, relative cerebral blood flow, and mean transit time in the lesion. MR spectroscopy demonstrated reduction in metabolites and a prominent lactate peak in both the patients. The pathological and pathophysiological significance of these findings is discussed.

CONCLUSION

MRI with the newer imaging capabilities can demonstrate the pathology and pathophysiology in Lhermitte-Duclos disease better. SWI helps in detecting the veins around the thickened folia.

Retroperitoneal ganglioneuroma with lymphnode metastasis: a case report

Ganglioneuroma is a benign, most differentiated tumor of neural crest origin. These tumors though benign, can very rarely metastasize to regional lymphnodes or to distant sites. We report a case of a 52 year old lady who presented to the surgical OPD with dyspeptic symptoms of 2 months duration. Ultrasonography and CT scan of the abdomen showed a homogenous mass in the region of the right adrenal gland, extending between the inferior vena cava and the aorta. A clinical and radiological diagnosis of an adrenal tumor was made. Microscopically, the tumor histology was that of a ganglioneuroma (schwannian stroma-dominant) mature type. The lymph node attached to the tumor showed metastasis, the metastatic foci having the same morphology as the primary tumor. The right adrenal gland was free of tumor. The case is illustrative due to its clinical presentation mimicking an adrenal incidentaloma, and a rare phenomenon of a benign tumor exhibiting completely differentiated lymph node metastasis.

Ampullary ganglioneuroma: an unusual feature of neurofibromatosis type 1--a case report

The case of a 65 year old man is presented. He had a history of dyspepsia and was diagnosed as neurofibromatosis clinically. Upper G.I. endoscopy showed thickened folds in duodenum. A polyp was seen at the junction of D1 and D2 adjacent to the ampulla. Duodenal biopsy results were suggestive of ganglioneuroma.

Lhermitte-Duclos disease: a report of 31 cases with immunohistochemical analysis of the PTEN/AKT/mTOR pathway

Lhermitte-Duclos disease (LDD) is a rare cerebellar tumor associated with Cowden disease (CD) and germline mutations in the PTEN gene. To further define these relationships, we reviewed clinical and pathologic findings in 31 LDD cases and analyzed the status of the PTEN pathway in 11 of them. We hypothesized that the granule cell hypertrophy in LDD is secondary to activation of mammalian target of rapamycin (mTOR), a downstream effector in the PTEN/AKT pathway and a major regulator of cell growth. Histopathologically, in addition to the classical findings of LDD, we observed prominent vascular proliferation and vacuolization of the white matter in many of the lesions. Four patients met diagnostic criteria for CD, and many of the remaining patients had some clinical features of CD. Immunohistochemical analysis showed high levels of phospho-AKT and phospho-S6 in the large ganglionic cells forming the lesions, indicating activation of the PTEN/AKT/mTOR pathway and suggesting a central role for mTOR in the pathogenesis of LDD. These data support recommendations for genetic testing and screening for CD in patients with LDD and suggest a novel therapy for LDD through pharmacologic inhibition of mTOR.

Atypical ganglion cell tumor of the sciatic nerve

CONTEXT

Although herniation of a lumbosacral intervertebral disk is a major cause of sciatic distribution pain, relentlessly progressive symptoms or signs should alert one to the possibility of a tumor involving the nerve.

OBJECTIVE

To describe the clinical, neurophysiological, and histological features of a pathologically unique tumor involving the sciatic nerve.

SETTING

Tertiary referral university hospital.

PATIENT

A 36-year-old woman was seen with a 6-year history of increasingly severe symptoms in the distribution of the left sciatic nerve.

RESULTS

Electromyography indicated a sciatic nerve lesion in the region of the greater sciatic notch. Magnetic resonance imaging demonstrated a tumor involving the left sciatic nerve in this area. Light microscopy, electron microscopy, and immunohistochemistry results confirmed the presence of an atypical ganglion cell tumor of the sciatic nerve that exhibited prognostically conflicting clinical and histological features.

CONCLUSIONS

To our knowledge, this is the first report of an atypical ganglion cell tumor affecting the sciatic nerve, and illustrates the value of detailed neurophysiological examination in localizing the site of peripheral nerve injury to facilitate focused neuroimaging when standard investigations are uninformative. Longer follow-up is required to determine the true biologic potential of this lesion.

Ganglion cells in the posterior pituitary: result of ectopia or transdifferentiation?

Histologic examination revealed large ganglion cells within the posterior pituitary of an 80-year-old woman who died of myocardial infarction. Apparently fully mature, the cells were an incidental finding scattered within hyperplastic foci of pars intermedia (PI)-derived cells (basophil invasion) on histologic examination of the pituitary obtained at autopsy. Immunocytochemistry showed staining reactivity for neuron-specific enolase, synaptophysin, alpha subunit of the glycoprotein hormones and beta-endorphin. The presence of these ganglion cells with features similar to those of magnocellular hypothalamic neurons could be considered the result of abnormal migration during the early phase of embryonic life, or differentiation/maturation of neuroblasts, presumed to occur in the embryonic neurohypophysis. Alternatively, transdifferentiation from proliferating PI cells may explain the emergence of neurons; a hypothesis supported by the proximity and shared alpha subunit, and beta-endorphin immunoreactivities of the two cell types.

The human cerebellum and associative learning: dissociation between the acquisition, retention and extinction of conditioned eyeblinks

The present paper is part of a systematic exploration of the neural substrates of conditioned eyeblink responses in humans. Normal subjects and patients with lesions restricted to the cerebellum were examined for their ability to acquire new classically conditioned eyeblinks to an auditory conditioned stimulus and whether they were able to perform and extinguish a previously learned natural anticipatory eyeblink response - the kinesthetic threat eyeblink response (KTER). In classical conditioning to an auditory conditioned stimulus, cerebellar patients failed to acquire new conditioned responses. In contrast to this impairment, in the KTER task both cerebellar patients and control subjects exhibited a high incidence of anticipatory eyeblinks which were initiated before the forehead tap. These results indicate that the cerebellar circuits, which are critical for the acquisition of new conditioned responses, are not essential for the storage and expression of naturally acquired conditioned responses. In the extinction experiment, cerebellar patients failed to extinguish their KTERs. This finding suggests that in humans, the acquisition of new and the extinction of previously learned conditioned responses depends on a similar set of cerebellar circuits.

Spatial association of apoptosis-related gene expression and cellular death in clinical neuroblastoma

Several unique features of neuroblastoma (NB), including the capacity for spontaneous regression and maturation to benign pathology, suggest that genes that regulate cellular proliferation, survival and differentiation may be involved in directing clinical tumour aggressiveness. The in situ expression of Bcl-2, Rb, p21, p53 and Bax proteins, as well as the proliferation marker proliferating cell nuclear antigen (PCNA) were examined immunocytochemically in a selection of 38 stage- and outcome-identified NB tumours. Apoptotic cells were identified morphologically and by a DNA fragmentation labelling technique (TUNEL). Although the tumour cell density of Bcl-2, p53, Bax, PCNA and TUNEL positivity correlated with patient survival, a spatially organized expression pattern was further recognized in stroma-poor differentiating tumours. Immature tumour cells adjacent to thin fibrovascular stroma are proliferating, as evidenced by PCNA positivity, and often express Bcl-2. At increasing distance from this fibrovascular stroma, intermediately differentiated tumour cells express Rb, while with more advanced differentiation, proliferation ceases and Bcl-2 immunoreactivity is lost. The most differentiated tumour cells, which often express p53, and occasionally p21 and Bax, lie adjacent to TUNEL-positive, morphologically apoptotic cells. This spatial organization in favourable outcome NB tumours suggests that physiological regulation of differentiation and apoptosis may be involved in tumour regression.

[A case of intrathoracic dumb-bell ganglioneuroma and a surgical approach using spinal evoked potentials (SEP)]

A successfully treated case of a seven-year-old girl with a left intrathoracic Dumb-bell ganglioneuroma is reported. The tumor was 10 cm in diameter. Preoperative angiography revealed that the location of tumor was very close to the Adamkiewicz artery. In order to prevent the artery from damaging, spinal evoked potentials (SEP) was used during the surgery and was very useful for monitoring the spinal cord. Although SEP has often been employed in spine surgery, the literature on the use of it for posterior mediastinal tumor is scarce. It is considered that SEP is very useful for not damaging the feeding artery to the spinal cord, and for preventing the postoperative neurologic complications.

Dysplastic gangliocytoma and intractable partial seizures in childhood

We describe the clinical, radiologic, and EEG features of 3 children who had dysplastic gangliocytomas of the cerebral hemispheres and drug resistant partial seizures that began in infancy. Following cortical resection, 2 are seizure-free and the third almost seizure-free. The dysplastic gangliocytoma may be an important and surgically remediable cause of very early malignant partial seizures.

Expression of neurofilament proteins in the hypertrophic granule cells of Lhermitte-Duclos disease: an explanation for the mass effect and the myelination of parallel fibers in the disease state

The expression of neurofilament (NF) proteins was examined in the surgical specimen from a 42-year-old woman with Lhermitte-Duclos disease. Hypertrophic granule cell neurons of the dysplastic tissues were reactive with monoclonal antibodies, including antibodies to each of the three human NF subunits. Furthermore, antibodies to dephosphorylation-dependent epitopes on NF proteins stained the cell bodies of hypertrophic granule cells, whereas antibodies to phosphorylation-dependent epitopes stained the enlarged and myelinated axons of the hypertrophic granule cells. Enzymatic dephosphorylation of this tissue abolished axonal staining with phosphorylation-dependent antibodies and uncovered determinants recognized by antibodies to the dephosphorylated state of NF proteins. The NF protein immunoreactivity of hypertrophic granule cells was indistinguishable from that of large, NF-rich neurons in control human cerebellum, suggesting that a normal pattern of expression and phosphorylation of NF proteins occurs in hypertrophic granule cells in Lhermitte-Duclos disease. An increased expression of NF proteins by cerebellar granule cells may account for many of the observed alterations of Lhermitte-Duclos disease, including the hypertrophy of the granule cells and enlargement of their axons, leading to the myelination of parallel fibers within the molecular layer of the cerebellum. Attention should now be directed at the underlying mechanisms which lead to the coordinated up-regulation of the three NF genes and whether or not additional gene products or cell types are altered in Lhermitte-Duclos disease.

A pathophysiological study of the intestinal manifestations of a vasoactive intestinal peptide, calcitonin, and catecholamine-secreting tumour

A three year old girl with severe watery diarrhoea and a vasoactive intestinal peptide, calcitonin, and catecholamine-secreting supra-renal ganglioneuroblastoma is reported. Steady-state perfusion studies showed the jejunum to be in a net secretory state with respect to water, sodium, and chloride at low concentrations (2 mmol/l) of glucose whereas higher concentrations (56 mmol/l) reversed secretion to absorption; transmural rectal potential difference was increased (lumen negative); Na+ absorption by the rectum was impaired and secretion of potassium and bicarbonate excessive. Motility studies showed prolonged, slowly propagated migrating motor complexes with abnormal runs of non-propagated contractions in the fasting state. During perfusion with glucose, no postprandial activity occurred. These results suggest that diarrhoea results from small intestinal secretion with impaired colonic function and that tumour products may have a direct effect on intestinal motility.

Membrane surface properties of normal and malignant cells: partition in aqueous two-polymer phase systems

The partition of normal and malignantly transformed fibroblast lines and cell lines initiated from malignant human astrocytomas and a benign ganglioneuroma has been examined in aqueous dextran-polyethylene glycol phase system containing phosphate buffer with a low phosphate/sodium chloride ratio. The malignant astrocytomas showed a significantly lower partition coefficient as compared with the benign ganglioneuroma. Treatment of astrocytoma cells with dexamethasone caused an increase in the partitioning of the cell population. No differences were found in the partition behaviour of normal BHK-21 cells and their malignant transformants, the TRES fibrosarcoma cells. Polyoma and simian virus-transformed 3T3 fibroblasts showed partition ratios similar to the untransformed cells. Dexamethasone pre-treatment had no effect on the partition behaviour of these cells. The significance of these observations has been discussed in relation to the surface hydrophobicity and the neoplastic state.

Ganglioneuroblastoma presenting as myasthenia gravis

Neuroblastoma is one of the most common malignant neoplasms in infants and children under 5 years of age. The commonest manifestations are abdominal masses or metastases. The case reported showed unusual manifestations as the presenting features simulated myasthenia gravis in all aspects. He was a child, aged 3 years, who was admitted because of generalized weakness, inability to open his eyes and lethargy. Radiography showed an oval opacity at the right upper zone of the chest. A thorocotomy was performed and a tumour was removed from the posterior mediastinum. Histopathology confirmed diagnosis of ganglioneuroblastoma. There is only one similar report in the medical literature.

Intracranial ganglioneuromas in children

Two cases of tumours of the sellar and suprasellar region in children, manifested clinically by visual and endocrine disturbances, are reported. In both cases surgical removal of the intracranial tumour was performed. The histological diagnosis was central ganglioneuroma, an extremely rare tumour in children. Also worthy of note was the altogether exceptional location in these children of central ganglioneuromas in the sellar and suprasellar region.

Elevated plasma and tissue levels of vasoactive intestinal polypeptide in the watery-diarrhea syndrome due to pancreatic, bronchogenic and other tumors

The actions of the vasoactive intestinal polypeptide make it a potential candidate for mediating certain manifestations of the watery-diarrhea syndrome. Peptide levels were measured by radioimmunoassay in 25 controls and 30 patients with chronic watery diarrhea. Plasma levels were too low to measure (smaller 200 pg per milliliter) in 22 of the controls, averaging 79 plus or minus 64 pg per milliliter (S.D.). Levels were elevated in 26 of 28 plasma samples (5.1 plus or minus 2.5 ng per milliliter), and in each of 13 tissue extracts (5.1 plus or minus 10.9 mug per gram); in all, 28 patients had elevated levels in plasma or tissue or both. Thirteen patients had pancreatic islet-cell adenoma, four islet-cell hyperplasia, five bronchogenic carcinoma, and one each pheochromocytoma and ganglioneuroblastoma. The findings indicate that the peptide is a probable mediator of the watery-diarrhea syndrome, that the syndrome may result from a variety of non-pancreatic tumors, and that this or a related peptide may also be secreted by these tumors.

Neuroblastoma, its natural history and prognosis: a study of 487 cases

The natural history of neuroblastoma and factors affecting survival for this disease were studied in an unselected group of children notified to cancer registries in Britain during 1962-7. The three-year survival rate based on 487 cases was 23%; many of the cases were followed up for more than five years, and this made it possible to calculate long-term survival and recurrence rates. There were only five deaths among 110 cases followed for more than three years, 64 of the survivors having been followed for more than five years. Factors affecting the prognosis included age at diagnosis, site, histological grade at diagnosis, and the sex of the child. The interrelationship between these factors together with their effect on prognosis were analysed, and in particular we attempted to elucidate factors which might explain our observation that girls have a significantly better survival rate than boys. Direct histological evidence and also the analyses of survival and recurrence rates seem to support the suggestion that the likelihood of maturation for this tumour is greater for girls than for boys.