Faculty Bibliography

BACKGROUND: Meningioangiomatosis (MA) is a rare benign disorder. It may occur sporadically or in association with neurofibromatosis (NF). The sporadic type typically presents with seizures, whereas that associated with NF is often asymptomatic. Of the 100 cases reported, only 14 are associated with NF. We now report 2 additional cases of MA associated with neurofibromatosis 2 (NF2) in a single family, with one occurring in the cerebellum. The etiology, pathology, and imaging features of MA are presented. CASE DESCRIPTION: A 38-year-old woman (patient 1) presented with a 4-month history of ataxia. She had been diagnosed previously with NF2. Magnetic resonance imaging (MRI) scans of the brain revealed bilateral acoustic neuromas and multiple calcified intracranial lesions. Her 13-year-old daughter (patient 2) presented with complex partial seizures. MRI scans of the brain revealed bilateral acoustic neuromas and a right parietal mass. Patient 1 underwent a suboccipital craniotomy to resect the right-sided acoustic neuroma. A small portion of normal-appearing cerebellar cortex was resected to avoid undue retraction. Histopathologic examination showed the presence of a lesion consistent with MA. Patient 2 underwent a right temporal-parietal craniotomy to remove the enhancing epileptogenic right posterior temporoparietal lesion. Histopathologic analysis showed a lesion consistent with meningioma and MA. CONCLUSIONS: MA has been reported infrequently in association with NF2. We now report 2 cases of MA associated with NF2 in one family, and we add the cerebellum to possible locations of occurrence. MA should be considered in the differential diagnosis of cortical lesions, particularly in patients with NF2

The roles of the mitogen-activated kinase protein (MAPK) pathway, nuclear factor-kappa B (NF-kappaB), and activator protein-1 (AP-1) in cellular responses to growth factors and mitogen are well established. However, the manner by which these proliferative pathways are affected by the tumor suppressor protein p53 is not fully understood. We report here the results of an investigation of the status of p53 on two human melanoma cell lines with wild-type p53 (SK-Mel-186) or mutant p53 (SK-Mel-110). The basal levels of the activated extracellular-signal regulated kinases 1 and 2 (ERK1/2) were high in cells with wild-type p53, but low in cells with mutant p53. The 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of ERK1/2 through the phosphorylation of threonine and tyrosine at 202 and 204, respectively, was demonstrated in both cell lines, however, in a discrete manner. TPA-induced activation of ERK1/2 was sustained in wild-type p53 cells, while only a transient activation was seen in mutant p53 cells. Inhibition of MAPK kinase (MEK), an upstream kinase, by U0126, blocked TPA-induced activation of ERK1/2 in wild-type p53 cells and in mutant p53 cells. Treatment of wild-type p53 (SK-Mel 186) cells with small interfering RNA (siRNA) of p53 displayed a transient induction of activation of ERK1/2 following TPA treatment, indicating that p53 has a role in the regulation of the activation of ERK1/2. NF-kappaB activity decreased significantly in cells with wild-type p53, while enhanced NF-kappaB activity was evident in cells with mutant p53. The expression of either wild-type or mutant p53 had a similar effect on TPA-induced Jun N-terminal kinase (JNK) activation, indicating specificity for the ERK pathway. Similarly, AP-1 binding activity showed a transient variation in both cell lines after TPA treatment but with different kinetics. These observations suggest that both wild-type and mutant p53 can modulate the activation pathways for ERK1/2, and NF-kappaB distinctively, while modulating the pathways of JNK and AP-1 similarly. These differences may influence cellular processes such as proliferation, differentiation, and apoptosis

Tumors located in the region of the foramen of Monro often present with signs and symptoms of obstructive hydrocephalus. Various types of lesions occur in this location. We describe a case of a dysembryoplastic neuroepithelial tumor of the septum pellucidum presenting with obstructive hydrocephalus and its successful endoscopic excision. The surgical considerations and pathologic findings are discussed

BACKGROUND: An isolated or trapped fourth ventricle (TFV) is an occasional, serious sequela of hemorrhagic, infectious, or inflammatory conditions of the central nervous system. The TFV usually occurs after successful shunting of the lateral ventricles. It may be heralded by delayed clinical deterioration after an initial period of symptomatic improvement. The typical clinical findings suggest an expanding posterior fossa mass lesion. Surgical treatments include CSF diversionary procedures as well as open and endoscopic approaches. Complications related to the treatment of the TFV are common and relate to catheter obstruction and cranial nerve or brainstem dysfunction. METHODS: The author reviews the clinical features, pathophysiology, and available treatment options for the TFV, with special reference to complication avoidance and advances in ventriculoscopy and frameless stereotaxy. CONCLUSIONS: Treatment of the TFV remains a formidable challenge. However, prompt recognition and intervention may aid in the preservation of life and neurological function

BACKGROUND: Growing skull fractures and other enlarging skull defects are rare postoperative occurrences. We report here on a 10-month-old girl who presented with an enlarging burr hole and pseudomeningocele after an endoscopic third ventriculocisternostomy. METHODS: Evaluation of an enlarging subcutaneous mass at the site of the burr hole included computed tomography scans and magnetic resonance imaging, which revealed a pseudomeningocele. The patient underwent repair of the lesion, including dural closure and cranioplasty. CONCLUSIONS: Growing skull fractures or other enlarging bone defects may occur after burr hole placement, particularly in infants who require larger access sites for endoscopy