Terminology and classification of the cortical dysplasias

BACKGROUND

There have been difficulties in achieving a uniform terminology in the literature regarding issues of classification with respect to focal cortical dysplasias (FCDs) associated with epilepsy.

OBJECTIVE

S: To review and refine the current terminology and classification issues of potential clinical relevance to epileptologists, neuroradiologists, and neuropathologists dealing with FCD.

METHODS

A panel discussion of epileptologists, neuropathologists, and neuroradiologists with special expertise in FCD was held.

RESULTS

The panel proposed 1) a specific terminology for the different types of abnormal cells encountered in the cerebral cortex of patients with FCD; 2) a reappraisal of the different histopathologic abnormalities usually subsumed under the term "microdysgenesis," and suggested that this terminology be abandoned; and 3) a more detailed yet straightforward classification of the various histopathologic features that usually are included under the heterogeneous term of "focal cortical dysplasia."

CONCLUSION

The panel hopes that these proposals will stimulate the debate toward more specific clinical, imaging, histopathologic, and prognostic correlations in patients with FCD associated with epilepsy.

Local control and overall survival in atypical meningioma: a retrospective study

PURPOSE

To evaluate local control and overall survival after primary surgery for patients with atypical meningiomas.

METHODS AND MATERIALS

From the Department of Pathology database, we identified 491 cases of meningioma treated at the Cleveland Clinic Foundation from 1979 through 1995. Thirty-three were diagnosed with atypical meningioma. Eleven of the excluded patients had incomplete records, were lost to follow-up, or received treatment elsewhere. Of the 22 evaluable patients, 15 underwent gross total resection (GTR), 4 had a subtotal resection (STR), and 3 had a resection of unknown extent. Eight patients received radiation therapy (2 after initial resection and 6 after at least one recurrence). The median radiation dose was 5,400 cGy (range 3,500-5,940). The median age at presentation was 55.5 years, the male:female ratio was 14:8, and 19/22 patients had a Karnofsky performance score (KPS) > or =80. The independent variables analyzed for overall survival and local control were gender, KPS (> or =80 vs. < 80), extent of surgery (GTR vs. STR or unknown extent of surgery), and postoperative radiation therapy.

RESULTS

Median survival was 10.6 years, with a median follow-up of 5.5 years (range 1.5-14.8). Eight of the 22 patients had local recurrence, including 2/15 with GTR, 3/4 with STR, and all 3 patients who underwent resection of unknown extent. At 10 years, patients with GTR had a higher local control rate than those who had either a STR or a resection of unknown extent (87% vs. 17%; p = 0.02). The 5- and 10-year overall survival rates for the entire group were 91% and 76%, respectively. Patients who had GTR had 5- and 10-year overall survival of 87% and 87%, respectively. Patients with STR or resection of unknown extent had 5- and 10-year overall survival rates of 100% and 75%, respectively.

CONCLUSION

In patients with atypical meningiomas, gross total resection is associated with a lower recurrence rate than in subtotal resection.

Predictors of outcome after temporal lobectomy for the treatment of intractable epilepsy

To assess short- and long-term seizure freedom, the authors reviewed 371 patients who underwent anterior temporal lobectomy to treat pharmacoresistant epilepsy. The mean follow-up duration was 5.5 years (range 1 to 14.1 years). Fifty-three percent of patients were seizure free at 10 years. The authors identified multiple predictors of recurrence. Results of EEG performed 6 months postoperatively correlated with occurrence and severity of seizure recurrence, in addition to breakthrough seizures with discontinuation of antiepileptic drugs.

West Nile virus infection: a new acute paralytic illness

OBJECTIVE

To determine the clinical, laboratory, electrodiagnostic, radiologic, and pathologic characteristics that define the spectrum of CNS disease caused by West Nile virus (WNV) infection.

METHODS

The records of all patients hospitalized at the Cleveland Clinic from August 2002 to September 2002 with WNV infection were reviewed.

RESULTS

Of 23 cases, the median age was 74 years old, and 74% were men. Symptoms included fever (100%), altered mental status (74%), gastrointestinal complaints (43%), back pain (35%), and rash (26%). In half, meningitis or encephalitis overlapped with flaccid weakness that progressed over 3 to 8 days, with a tendency to be proximal and asymmetric. Laboratory abnormalities included hyponatremia (30%) and initial CSF neutrophilic pleocytosis. Electrodiagnostic studies in two patients showed reduced motor amplitudes with normal conduction velocities and active denervation. In two other patients, reduced sensory amplitudes were also seen. MRI changes included cauda equina enhancement and parenchymal spinal cord signal abnormalities and parenchymal or leptomeningeal signal changes in the brain. Autopsy in three cases showed chronic perivascular inflammation in the brain and inflammatory changes with anterior horn cell loss in the spinal cord.

CONCLUSION

An overlapping spectrum of meningitis, encephalitis, and myeloradiculitis occurs in CNS WNV infection. Fever, rash, abdominal and back pain, preceding a proximal, asymmetric flaccid weakness, with CSF pleocytosis help distinguish the motor syndrome from Guillain-Barré syndrome. Pathologic changes in the CNS resembled poliomyelitis.

Ganglioglioma and intractable epilepsy: clinical and neurophysiologic features and predictors of outcome after surgery

PURPOSE

To review the clinical, neurophysiologic, and radiological data of patients with ganglioglioma who had undergone evaluation and surgery in our Epilepsy Program.

METHODS

The medical and neurophysiologic records of 38 patients with intractable epilepsy and ganglioglioma were reviewed. Data underwent statistical analysis.

RESULTS

There were 28 temporal and 10 extratemporal resections, with a mean age at seizure onset of 10.5 years and mean age at surgery of 22 years. Five tumor resections performed earlier were recorded. Twenty-nine patients had auras and 20 had secondarily generalized seizures. All 28 patients with temporal tumor had complex partial seizures. Preoperative MRI demonstrated the tumor in 36 of 36 patients: 17 of 29 demonstrated gadolinium enhancement, and 17 of 36 had mass effect. Scalp interictal sharp waves were present in 32 patients, and in 15 they were multiregional. In two patients, scalp EEG seizure onset was from the hemisphere contralateral to the tumor. Postoperatively, 79% of patients (30 of 38) were seizure-free (Engel's class I) at 6 months, 72% at 1 year (26 of 36), and 63% at 2 years (20 of 32). Excellent outcome was associated with a lower age at operation (p = 0.008), shorter duration of epilepsy (p = <0.01), absence of generalized seizures (p = <0.01), and no epileptiform discharges on a postoperative EEG (p = 0.01).

CONCLUSIONS

Good surgical outcome is expected in patients with ganglioglioma despite years of medically resistant seizures. Good outcome may be achieved despite EEG findings that may conflict with tumor location, and is more likely when surgery is performed relatively soon after epilepsy onset.

Epithelioid smooth-muscle tumors of the uterus: a clinicopathologic study of 18 patients

Epithelioid smooth-muscle tumors of the uterus are uncommon neoplasms for which prognostic factors have not been well established. A retrospective follow-up study of 18 uterine epithelioid smooth-muscle tumors was performed. Patients ranged in age from 27 to 83 years (mean, 45 years) and were separated into three groups based on the nuclear grade of the epithelioid tumor cells. Two tumors had grade 1 nuclei; both were examples of intravenous leiomyomatosis. They had highest mitosis counts of 1 and 3 mitotic figures (MF)/10 high-power fields (HPF), no tumor cell necrosis was found, and both patients were alive with no evidence of disease at 64 and 5 months' follow-up. Ten tumors had grade 2 nuclei. All had highest mitosis counts of 0 to 3 MF/10 HPF, except one (5 MF/10 HPF). Tumor cell necrosis was absent in nine and only one had an infiltrative border. Tumor size ranged from 1.5 to 14 cm. Two tumors contained pleomorphic ("symplastic") multinucleated giant cells similar to those seen in bizarre leiomyomas. All nine patients with follow-up were alive with no evidence of disease 5 to 203 months postoperatively (median, 74 months). One patient had also received adjuvant radiation therapy. Six tumors had grade 3 nuclei. Highest mitosis counts of 4 to 9 MF/10 HPF were found in five; one had 1 MF/10 HPF. Maximum tumor size ranged from 4.5 to 13 cm. Two had tumor cell necrosis, and two had an infiltrative border. Two of these patients died of tumor 11 and 132 months postoperatively. The former had widespread metastases at initial surgery (stage IVb); the latter patient (stage I) developed the first of seven tumor recurrences 3 years postoperatively. Both patients had also received adjuvant chemotherapy. Of the remaining four patients, two were alive with no evidence of disease at 48 and 83 months, one was alive (tumor status unknown) at 28 months, and one was lost to follow-up. Based on our findings and those in the literature, we conclude that uterine smooth-muscle tumors with a predominance of epithelioid cells are extremely uncommon and metastasize infrequently. No single histologic feature is predictive of metastatic potential. Clinically malignant tumors (i.e., epithelioid leiomyosarcomas) typically have the combination of significant nuclear atypia (either grade 2 or grade 3 nuclei) and some mitotic activity (usually at least 3 to 4 MF/10 HPF); most also have tumor cell necrosis.

Coexistence of neoplasia and cortical dysplasia in patients presenting with seizures

Tumors and cortical dysplasia are associated with epilepsy, but few studies have examined the coexistence of neoplasia and dysplasia in these patients. We studied 13 patients (age 4-29 years) with recurrent seizures of 1 month to 21-year' duration (median 72 months). Ten patients were aged < 21 years. Imaging studies localized the lesion to the temporal lobe (10 patients), parietal lobe (2 patients), and frontal lobe (1 patient). Tumors included ganglioglioma (8 patients), dysembryoplastic neuroepithelial tumor (DNT) (3 patients), and low-grade astrocytoma (2 patients). Cortical dysplasia, including atypical aggregates of neurons (6 patients), multifocal loss of the cortical laminar architecture (7 patients), and neurons in the molecular layer of the cortex (3 patients) were observed near but separate from the tumor. Coexistence of certain tumors with cortical dysplasia, most frequently observed in the pediatric population, suggests a hamartomatous/dysplastic nature of the neoplasms.

Cortical dysplasia: a histopathologic study of 52 cases of partial lobectomy in patients with epilepsy

In utero migrational abnormalities account for most cases of cortical dysplasia. The histopathologic appearance of cortical dysplasia is often varied, making recognition and classification difficult. We studied 52 patients with cortical dysplasia who underwent partial lobectomy for medically intractable seizures in order to devise a simple histopathologic classification schema. The incidence of observed dysplasia in lobectomy specimens over an 11-year period (n = 360) was 14%. Patients ranged in age from 3 months to 47 years at the time of surgery (mean, 19 years; 29 male and 23 female patients). The temporal lobe was involved in 34 patients, frontal lobe in 18, parietal lobe in four, and occipital lobe in three. In three patients multiple lobes showed dysplasia. Dysplasia was right-sided in 29 patients and left-sided in 23 patients. Dysplasia was focal in 23 patients, multifocal in four patients, and diffuse in 25 patients. Three main histologic patterns of cortical dysplasia were observed: (1) a cortical laminar architectural disorganization and/or malalignment of neurons (26 patients), (2) clusters of atypical neurons and glia within the cortex (28 patients), and (3) a hypercellular molecular layer with increased numbers of neurons and glia (31 patients). In 23 patients more than one pattern of dysplasia was identified. Coexistent tumors were present in 13 patients, including ganglioglioma (eight patients), dysembryoplastic neuroepithelial tumor (three patients), and low-grade astrocytoma (two patients). Tuberous sclerosis was present in four patients. We conclude that most types of cortical dysplasia can be divided into three main histologic patterns, facilitating the recognition of dysplasia. In addition to the known association with tuberous sclerosis, tumors may coexist with cortical dysplasia.

Cortical architectural abnormalities and MIB1 immunoreactivity in gangliogliomas: a study of 60 patients with intracranial tumors

Gangliogliomas are generally low grade neoplasms composed of mixtures of neoplastic glial and neuronal elements whose origin and exact nature are still controversial. We studied a series of 60 intracranial gangliogliomas looking for coexistent cortical architectural abnormalities (cortical dysplasia, microdysgenesis) and to determine if tumor behavior correlates with MIB1 (marker of cellular proliferation) labeling. The patients included 34 males and 26 females who ranged in age from 6 months to 55 years (mean 20 years). Thirty-eight tumors (63%) were located in the temporal lobe and 6 (10%) in the frontal lobe. Fifty-four patients (90%) presented with seizures (most with intractable epilepsy) and the duration of seizures ranged from 1 to 38 years (mean 14 years). In all cases, the predominant glioma component resembled a low grade fibrillary astrocytoma. In 14 tumors (23%), an oligodendroglial component was present. In one case, the glial component resembled an anaplastic astrocytoma. The tumors were characterized variously by perivascular chronic inflammation (N = 45, 75%), vascular proliferation (N = 36, 60%), granular bodies (N = 54, 90%), binucleated neurons (N = 36, 60%), calcification (N = 28, 47%), and cystic degeneration (N = 26, 43%). Meningeal involvement by tumor was observed in five (8%) cases. In 38 patients, sufficient tissue was resected to evaluate for the presence of concomitant cortical architectural abnormalities. Cortical architectural abnormalities were identified near to but clearly separate from the tumor in 19 (50%) patients. Only four patients including the anaplastic tumor died with tumor progression. MIB1 indices (positive tumor cells/1,000 tumor cells counted) in 54 cases ranged from 0 to 10.2 (mean 1.1 +/- 1.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic T cell adoptive immunotherapy of malignant gliomas

OBJECT

To determine the feasibility, toxicity, and potential therapeutic benefits of systemic adoptive immunotherapy, 10 patients with progressive primary or recurrent malignant glioma received this treatment. Adoptive immunotherapy, the transfer of immune T lymphocytes, is capable of mediating the regression of experimental brain tumors in animal models. In animal models, lymph nodes (LNs) that drain the tumor vaccine site are a rich source of tumor-immune T cells.

METHODS

In this clinical study, patients were inoculated intradermally with irradiated autologous tumor cells and granulocyte macrophage-colony stimulating factor as an adjuvant. Cells from draining inguinal LNs, surgically resected 7 days after vaccination, were stimulated sequentially with staphylococcal enterotoxin A and anti-CD3, and a low dose of interleukin-2 (60 IU/ml) was used to expand the stimulated cells. The maximum cell proliferation was 350-fold over 10 days of culture. The activated cells were virtually all T cells consisting of various proportions of CD4 and CD8 cells. These cells were given to patients by intravenous infusion at doses ranging from 9 x 10(8) to 1.5 x 10(11). There were no Grade 3 or 4 toxicities associated with the treatment. Following T-cell transfer therapy, radiographic regression that lasted at least 6 months was demonstrated in two patients with recurrent tumors. One patient demonstrated stable disease that has lasted for more than 17 months. The remaining patients had progressive disease; however, four of the eight patients with recurrent tumor remain alive more than 1 year after surgery for recurrence. Three patients required intervention with corticosteroid agents or additional surgery approximately 1 month following cell transfer.

CONCLUSIONS

These intriguing clinical observations warrant further trials to determine whether this approach can provide therapeutic benefits and improve survival.

Surgical pathologic findings of extratemporal-based intractable epilepsy: a study of 133 consecutive resections

BACKGROUND

Surgical management of intractable epilepsy continues to be important in select cases to achieve seizure control.

DESIGN

This study retrospectively reviews the pathologic findings in 133 consecutive cases of extratemporal lobe epilepsy experienced during a 17-year period.

RESULTS

The study group consists of 133 patients (78 males) who underwent extratemporal lobe resection for epilepsy at a mean age of 21.1 years (range, 3 months to 57 years). In 50 patients (37.6%), cortical dysplasia (neuronal migration abnormalities) was identified. The most common patterns of dysplasia observed included diffuse architectural disorganization in 46 cases, neuronal cytomegaly in 30 cases, increased numbers of molecular layer neurons in 30 cases, and balloon cells in 18 cases. Tumors were identified in 37 cases (27.8%) and included 13 astrocytomas, 7 gangliogliomas, 6 dysembryoplastic neuroepithelial tumors, 6 glioneuronal hamartomas, 4 oligodendrogliomas, and 1 oligoastrocytoma (mixed glioma). Twenty-four resections (18%) showed evidence of remote ischemic damage or infarct. Neuronal heterotopia was identified in 59 resection specimens (44.4%). Other less common findings included vascular malformations in 4 patients (3.0%), Sturge-Weber malformations in 3 patients (2.3%), and Rasmussen encephalitis in 2 patients (1.5%). Two patients were known to have tuberous sclerosis. In 23 resection specimens (17.3%), no significant pathologic finding was identified. Coexistent cortical dysplasia and tumor were seen in 10 cases and coexistent dysplasia and infarct or remote ischemic damage in 11 cases.

CONCLUSION

This series demonstrates that most patients with extratemporal lobe epilepsy have significant histopathologic findings, which most frequently include cortical dysplasia, tumor, or evidence of remote ischemic damage or infarct. Coexistent pathologic findings were present in a significant minority of cases (16.5%).

Mitotically active leiomyomas of the uterus

A series of 15 uterine smooth muscle tumors with histologic features of typical leiomyomas, except for the presence of mitotic activity exceeding 4 mitotic figures per 10 high-power fields (HPF), were studied. The patients' ages ranged from 25 to 50 years (median, 37 years). At least 60% of the tumors were submucosal. The maximum dimension of the tumors ranged from 1.3 to 8.0 cm (median, 3.8 cm). On gross examination, the tumors appeared to be generally unremarkable. By definition, none had cytologic atypia. Mitosis counts were performed in the most active areas by two methods. Counts ranged from 5 to 15 mitotic figures per 10 HPFs when the highest count in any single set of 10 HPFs was recorded (method A) and from 4.2 to 10.2 mitotic figures per 10 HPFs when the average count from 50 consecutive HPFs was determined (method B). Treatment included hysterectomy in eight patients, myomectomy followed by hysterectomy in one, and myomectomy only in six. All but one patient with evaluable endometria were in the secretory phase of the menstrual cycle. Follow-up periods ranged from 6 months to 10.5 years (mean, 2.5 years; median, 2.1 years). None developed local recurrences or metastases. The benign clinical behavior of such tumors warrants the designation of mitotically active leiomyoma rather than smooth muscle tumor of uncertain malignant potential or low-grade leiomyosarcoma.

Interobserver reproducibility among neuropathologists and surgical pathologists in fibrillary astrocytoma grading

Many of the problems associated with the current grading approaches for fibrillary astrocytomas center around the lack of consistency in grading. This study compares the diagnoses of five neuropathologists with five experienced surgical pathologists with regard to assigning astrocytoma grade. Thirty neoplastic and non-neoplastic lesions were sent to each of five neuropathologists and five surgical pathologists for placement into one of three grades as outlined by modified Ringertz schema. Grading criteria (Burger et al., 1985. Cancer 56:1106-1111) were distributed to all participants, who have been practicing for at least 5 years. An additional category for non-neoplastic or normal tissue was also provided. The diagnoses, based on the majority opinion of the neuropathologist group, included six low grade astrocytomas, 11 anaplastic astrocytomas, seven glioblastoma multiforme, and six normal/reactive lesions. Agreement by all neuropathologists was reached in 12 cases (40%). A discrepant diagnosis was obtained in one of five neuropathologists in 14 additional cases (46.7%). In the remaining four cases, two neuropathologists deviated from the majority opinion; in each of these cases, the diagnostic problem involved differentiating tumor from reactive gliosis. All five surgical pathologists agreed in six cases (20%). One discrepant diagnosis among the surgical pathologist group was seen in seven cases (23.3%). In the remaining 17 cases, two or more discrepant diagnoses were obtained (56.7%); discrepancies in these cases included differences in assignment of tumor grade and in distinguishing low grade astrocytoma from gliosis.

IN CONCLUSION

(1) it is likely that experience with grading accounts for the better level of agreement among the neuropathologist group (kappa statistic 0.63) versus the surgical pathologist group (kappa statistic 0.36); (2) in most cases, the neuropathologists all agreed or had one discrepant diagnosis (86.7%) versus the surgical pathologist group (43.3%); (3) the discrepancies in diagnosis among both groups is likely related, in good part, to the limitations of the grading schema in fully enumerating the spectrum of such grading parameters as cytologic atypia and vascular proliferation.

Seizure outcome after surgery for epilepsy due to malformation of cortical development

PURPOSE

To explore seizure outcome after surgery for focal epilepsy due to malformation of cortical development (MCD), with focus on the role of MRI.

METHODS

Thirty-five patients who had surgery for intractable focal epilepsy due to MCD identified by preoperative MRI and confirmed by histopathologic analysis of resected tissue were studied. Patients were aged 3 months to 47 years (median, 14 years) at the time of surgery. Duration of follow-up was 1 to 7.9 (mean, 3.4) years.

RESULTS

At latest follow-up, 17 patients (49%) had Engel Class I outcome with no seizures or auras only; eight patients (23%) had Class II outcome, with rare disabling seizures; seven patients (20%) had worthwhile improvement; and three patients (9%) had no improvement. Seizure-free outcome tended to be more frequent among patients who had complete resection of unilateral MCD (excluding hemimegalencephaly) based on postoperative MRI (7/12; 58%), compared with patients with unilateral MCD who had incomplete resection (3/11; 27%), but the difference was not significant. The frequency of seizure-free outcome did not differ significantly between children (8/14; 57%), adolescents (7/15; 47%) or adults (2/6; 33%); between patients who had daily (12/24; 50%), weekly (4/9; 44%), or monthly (1/2; 50%) seizures preoperatively; between patients who had temporal (2/6; 33%) or extratemporal or multilobar resections (14/28; 50%); or between patients who were (9/16; 56%) or were not (8/19; 42%) studied with subdural electrodes. Results for all analyses were similar when analyzed at latest available follow-up or at 1 year after surgery.

CONCLUSIONS

Surgery can offer seizure-free outcome for approximately one half of carefully selected patients with intractable focal epilepsy due to MCD. Complete resection of the MRI-apparent lesion may improve the likelihood for favorable outcome. MRI evidence of hemimegalencephaly or bilateral MCD suggests a low likelihood for postoperative freedom from seizures.

MIB-1 labeling indices in benign, aggressive, and malignant meningiomas: a study of 90 tumors

Predicting tumor behavior in meningiomas based on histology alone has been problematic. This study retrospectively compares histology and MIB-1 (cell proliferation marker) labeling indices (LI) in benign, aggressive, and malignant meningiomas. Six histological features, including mitoses, necrosis, loss of pattern, hypervascularity/hemosiderin deposition, prominent nucleoli, and nuclear pleomorphism, were compared in 90 meningiomas (Fisher's exact test). Tumors with two or more of the above features were designated as aggressive meningiomas. Malignant meningiomas were characterized by brain invasion or metastasis. The MIB-1 LIs (% positive tumor cell nuclei) were compared between the three groups (Kruskal-Wallis test, Wilcoxon two-sample test). Of the benign meningiomas (n=37; mean age, 54 years), 41% had one of the six histological features, with nuclear pleomorphism (n=10) being the most frequent. The aggressive tumors (n=29; mean age, 61 years) were characterized by nuclear pleomorphism (n=28), mitoses (n=20), necrosis (n=16), loss of pattern (n=16), prominent nucleoli (n=6), and hypervascularity/hemosiderin deposition (n=5). Malignant tumors (n=24; mean age, 59 years) were characterized by nuclear pleomorphism (n=22), mitoses (n=21), loss of pattern (n=21), necrosis (n=21), nucleoli (n=17), and hypervascularity/hemosiderin deposition (n=3). Significant differences were found between the aggressive and malignant groups with regard to loss of pattern, necrosis, and nucleoli (P=.0043, .011, and .00029, respectively). Mean MIB-1 LIs for the benign, aggressive, and malignant groups were 1.0% (range, 0 to 5.5%),5.5% (range, 0.1 to 32.5%), and 12.0% (range, 0.3 to 32.5%), respectively. Differences in the mean MIB-1 LI between groups were statistically significant, with P values of <.0001 (benign v aggressive) and .0012 (aggressive v malignant). Mean MIB-1 LIs for recurrent versus nonrecurrent tumors were 7.1% (range, 0 to 32.5%) versus 3.8% (range, 0 to 20.9%) (P=.32). The mean MIB-1 LI for patients who were alive with or without tumor was 6.2% (range, 0 to 32.5%) versus a mean MIB-1 LI of 14.2% (range, 2.8% to 32.5%) for patients who died of or with tumor (P=.0013). In conclusion, (1) There is a statistically significant difference in the increasing MIB-1 LI means between benign, aggressive, and malignant meningiomas and between patients who were alive versus those who died; (2) there is some overlap in MIB-1 LI ranges between groups, which warrants caution in interpreting an individual MIB-1 LI in a given tumor.

Dysembryoplastic neuroepithelial tumor

Dysembryoplastic neuroepithelial tumor is a recently described but rare tumor that occurs in children and characterized by long-standing, intractable partial complex seizures. Due to a paucity of literature on this condition and its heterogeneous cellular composition, dysembryoplastic neuroepithelial tumors can present difficulties in diagnosis. The authors describe two cases of dysembryoplastic neuroepithelial tumor occurring in young patients (ages 8 and 19 years). Both tumors were located in the temporal lobe. Temporal lobectomy with excision of mesial structures resulted in resolution of the seizures. Differential diagnosis includes oligodendrogliomas, mixed gliomas, and gangliogliomas. Features of the dysembryoplastic neuroepithelial tumor that are useful in making the distinction include a multinodular and multicystic appearance, the presence of both neuronal and glial (oligodendrocytic and astrocytic) components with little if any cytologic atypia, the presence of accompanying cortical dysplasia, and the lack of an arcuate vascular pattern. Because dysembryoplastic neuroepithelial tumors are curable by excision, the recognition and correct diagnosis of this tumor is important.

Clinicopathologic study of 61 patients with ependymoma including MIB-1 immunohistochemistry

Predicting behavior based on histologic appearance has been problematic in ependymomas. Sixty-one patients with ependymoma (excluding subependymoma and myxopapillary ependymoma) were studied. The patients included 36 men and ranged in age from 1.5 to 74 years (median, 33 years). The most common clinical presentations included headache (n = 19), weakness (n = 18), nausea/vomiting (n = 12), and gait disturbance (n = 10). Location included spinal cord (n = 24), fourth ventricle (n = 21), lateral ventricle (n = 8), and third ventricle (n = 5). Initial surgery included a gross total resection of tumor in 22 patients and subtotal resection or biopsy in the remaining patients. Thirty-five patients were known to have been treated with adjuvant radiation therapy and 13 patients received adjuvant chemotherapy. At last known follow-up, 20 patients were alive with no evidence of tumor (median, 66.5 months), 17 patients were alive with residual tumor (median, 14 months), and 12 patients died of tumor (median, 27.5 months). Two additional patients are alive with tumor status not known, two cases are current, and two patients were lost to follow-up. The additional six patients died either shortly after surgery or of surgical complications. Sixteen of 18 patients had at least one tumor recurrence at median 28.5 months. Fifty-one tumors had a predominantly glial pattern and 10 had a mixed glial-epithelial pattern. Of histologic features examined, patients with tumor recurrence or who died of tumor more frequently had observable mitotic figures, vascular proliferation, necrosis, and foci of increased cellularity. Eight of 18 recurrent tumors were classified as high grade ependymomas (anaplastic/malignant). Of patients who died of tumor, 4 of 12 had histologically high grade tumors versus 5 of 39 of the remaining tumors. MIB-1 immunostaining (marker of cell proliferation) was performed on 50 tumors. MIB-1 labeling indices (% positive tumor cell nuclei) ranged from 0.1 to 34.0 (median, 1.1). A higher percentage of patients with recurrent tumor (6 of 13, 46%) or who died of tumor (3 of 10, 30%) had MIB-1 indices >/= 4.0 versus the remaining patients (8 of 33, 24%). The conclusions are as follows: (1) histologic appearance and MIB-1 indices were not reliably predictive of tumor behavior, probably due in part to tumor heterogeneity; (2) tumors with two or more of the following features: identifiable mitotic figures, hypercellularity, vascular proliferation, and necrosis were more likely to behave in an aggressive manner; and (3) elevated MIB-1 labeling indices (>/=4.0 in this study) were encountered in a higher percentage of fatal and recurrent tumors than in nonfatal or nonrecurrent tumors.

Granulomatous myositis. Clinicopathologic study of 12 cases

Granulomatous inflammation is infrequently encountered in skeletal muscle biopsy material. Of 2,985 muscle biopsy specimens reviewed over 12 years, 12 (0.4%) with granulomatous inflammation were identified. The patients included 9 women who ranged in age from 24 to 76 years (mean 50.3 years). The most common clinical findings included decreased strength or weakness in the extremities (n = 8), muscle pain (n = 5), and weight loss (n = 3). All muscles exhibited nonnecrotizing granulomas; an associated vasculitic process was identified in 2. Endomysial chronic inflammation consisting primarily of lymphocytes and plasma cells was present in 10 muscles, and perivascular chronic inflammation in 8. Degenerating muscle fibers were noted in 10 cases, and regenerating fibers in 11. Evidence of neurogenic atrophy was seen in 8 muscles. Increased endomysial fibrosis was observed in 5 muscles, and type II muscle fiber atrophy in 5 muscles. Stains for acid-fast bacilli and Gomori methenamine silver stain were performed in all but 2 cases and failed to demonstrate organisms. In 3 cases, concomitant sural nerve biopsies were performed, and granulomas were identified in 2 of those cases. Clinicopathologic diagnoses included sarcoidosis (n = 6), vasculitis (n = 2), and granulomatous myositis not otherwise specified (n = 2). In 2 cases, there was insufficient clinical information or follow-up data to determine a cause. In conclusion, granulomatous myositis is infrequently found in muscle biopsy specimens (0.5% of all biopsies in this series); most muscles demonstrate evidence of chronic endomysial or perivascular inflammation accompanied by muscle fiber degeneration and regeneration; and the most common cause for granulomatous myositis was sarcoidosis in this series.

Histopathological correlates of epileptogenicity as expressed by electrocorticographic spiking and seizure frequency

PURPOSE

To study the correlation between histopathology and epileptogenicity, as measured by seizure frequency and electrocorticography (EcoG), in patients with cortical dysplasia (CD) as compared with control patients with gangliogliomas or gliomas.

METHODS

The influence of the histopathological classification and the presence of balloon cells in CD on the frequency and extension of five predefined patterns of ECoG spiking, seizure frequency, age of seizure onset and 6-month postoperative outcome were analyzed in 32 patients with focal epilepsy undergoing presurgical evaluation with chronically implanted subdural electrodes.

RESULTS

Comparison of patients with CD, gangliogliomas, and gliomas showed that the seizure frequency was greatest in patients with CD and ECoG spiking and was most extensive in patients with gangliogliomas. The onset of epilepsy was earlier in patients with CD and with gangliogliomas. None of these differences was significant. However, in patients with CD, the presence of balloon cells was associated with significantly greater seizure frequency (p=0.009), and a significantly greater number of electrodes recording continuous frequent spiking (p=0.03). The presence of continuous very frequent spiking correlated with the duration of the epilepsy and the number of seizures recorded during monitoring. No significant correlation was detected between histopathology, seizure frequency, or ECoG activity and postoperative outcome, which was relatively favorable in patients with balloon cells.

CONCLUSIONS

CD refers to a variety of histopathological patterns associated with different epileptogenicity. In CD, increased clinical and ECoG epileptogenicity correlates with the presence of balloon cells. This finding confirms that balloon cells should be considered in the histopathological classification of CD. The predefined ECoG were not specific for any of the histopathologies investigated.

Epilepsy surgery in the setting of periventricular leukomalacia and focal cortical dysplasia

We report an infant who had successful epilepsy surgery for intractable infantile spasms in the setting of bilateral periventricular leukomalacia and remote germinal matrix hemorrhage. Although MRI gave evidence of a diffuse cerebral insult and EEG showed hypsarrhythmia, focal epileptogenicity was suggested by previous partial seizures with onset over the right temporoparietal-occipital region and PET hypometabolism in that same area. Right temporoparietal and lateral occipital resection at 15 months resulted in seizure freedom and dramatic developmental progress at 1-year follow-up. Histopathologic examination of resected tissue showed cortical dysplasia, possibly due to the same insult that also resulted in the bilateral periventricular leukomalacia. From an etiologic perspective, this is one of very few reported cases strongly implicating acquired focal cortical dysplasia in response to a prenatal insult. From a clinical perspective, the case illustrates that the spectrum of potential surgical candidacy in infants may be broader than usually suspected.

Subependymomas: clinicopathologic study of 14 tumors, including comparative MIB-1 immunohistochemical analysis with other ependymal neoplasms

BACKGROUND

Subependymomas are uncommonly encountered ependymal tumors, which are important to distinguish from ordinary ependymomas because of their generally better prognosis.

OBJECTIVE

To review the clinicopathologic features and MIB-1 labeling indices (marker of cell proliferation) of 14 subependymomas.

DESIGN

Retrospective review of 14 subependymomas encountered in a tertiary care setting.

RESULTS

Fourteen ependymomas presenting in 8 men and 6 women between the ages of 18 and 78 years (mean, 53.6 years) comprise the study group. The most common clinical presentations included ataxia (n = 4), dizziness/vertigo (n = 3), nausea/vomiting (n = 3), headaches (n = 3), and incidental finding at autopsy (n = 2). Tumor locations included fourth ventricle (n = 7), lateral ventricle (n = 4), third ventricle (n = 2), and thoracic spinal cord (n = 1). Eight patients underwent gross total resection, and 4 had subtotal resection. Tumors were characterized by clustering of cell nuclei arranged against a fibrillary background. Focal cystic degeneration was seen in 10 tumors, hemosiderin deposition in 8 tumors, sclerotic vessels in 8 tumors, calcifications in 5 tumors, and focal nuclear pleomorphism in 2 tumors. Mitotic figures, vascular endothelial proliferation, and necrosis were not seen in any of these tumors. Cell proliferation marker MIB-1 labeling indices (percentage of positive staining tumor cells) ranged from 0 to 1.4 (mean, 0.3). In comparison, 13 myxopapillary ependymomas had labeling indices ranging from 0 to 5.5 (mean, 1.1). Thirty-nine low-grade ependymomas had MIB-1 labeling indices of 0.1 to 5.4 (mean, 1.1). Fourteen anaplastic/malignant ependymomas had MIB-1 labeling indices ranging from 0.4 to 34.0 (mean, 12.8). One subependymoma was treated with radiation therapy. Six patients were alive with no evidence of tumor at a mean follow-up of 94.4 months. Two patients were alive with residual tumor (follow-up of 4 and 53 months). Two patients died with tumor at 0.67 and 43.4 months. One patient was lost to follow-up, 1 is a recent case, and 2 were incidental findings at autopsy. None of the patients developed tumor recurrence.

CONCLUSIONS

Subependymomas are generally low-grade lesions, as evidenced by their benign clinical course and low MIB-1 labeling indices. Compared with other ependymal tumors, subependymomas have the lowest rate of cell proliferation as evidenced by MIB-1 immunostaining.

Histopathologic findings in 107 uterine leiomyomas treated with leuprolide acetate compared with 126 controls

The reported histopathologic findings in leiomyomas treated with leuprolide acetate (LA) differ. We examined 233 myomectomy specimens, including 107 myomas from 30 patients (mean age, 34.7 +/- 4.6 years) treated with LA. Their histopathologic findings were compared with those from a control group of 126 myomas from 30 untreated patients (mean age 32.7 +/- 5.3 years). The LA-treated leiomyomas had myxoid change (n = 2; 1.9%), total necrosis (n=4; 3.7%), focal necrosis (n = 5; 4.7%), calcifications (n = 5; 4.7%), hemorrhage (n = 8, 7.5%), vascular changes (n = 12; 11.2%), hydropic degeneration (n = 22; 20.5%), and hyalinization (n = 61; 57.0%). None of these changes differed significantly from the untreated controls. None of the LA-treated leiomyomas had nuclear atypia, whereas nuclear atypia occurred in four (3.2%) of the untreated leiomyomas; this difference was also not significant. Mitotic figures were present in 8.4% of the LA-treated myomas and 8.5% of untreated controls. The number of mitotic figures per 10 high-power fields was slightly higher in the untreated myomas, but the difference was not statistically significant (range, 0-3 for treated, 0-5 for controls). The degree of cellularity did not differ between the two groups. In conclusion, (a) LA-treated myomas do not significantly differ from untreated myomas with respect to nuclear atypia, calcification, total coagulative necrosis, focal coagulative necrosis, hemorrhage, vascular changes, myxoid change, hydropic degeneration, hyalinization, mitotic activity, or cellularity; and (b) the mechanism leading to a reduction in the size of myomas treated with LA is not apparent from routine histologic examination.

Malignant meningioma: a clinicopathologic study of 23 patients including MIB1 and p53 immunohistochemistry

Malignant meningiomas are rarely encountered neoplasms. Few studies have examined MIB1 (marker of cell proliferation) or p53 (tumor suppressor gene) immunoreactivity in these tumors. This study retrospectively examines 23 malignant meningiomas (defined by the presence of either unequivocal brain invasion or metastasis) including MIB1 and p53 immunohistochemistry. The patients included 13 women and 10 men who ranged in age from 22 to 82 years (mean 63 years). Initial clinical presentation included weakness or numbness in 10 patients, visual signs or symptoms in 7 patients, and headaches in 6 patients. Histologically, nuclear pleomorphism was present in 23 of 23 tumors, disorganized architecture in 22 of 22, necrosis in 20 of 23, prominent nucleoli in 17 of 23, and hypervascularity in 4 of 23. One to 18 mitotic figures per 10 high power fields (HPF) (mean 6.1) were observed. Metastases were present in six patients (bone: 3 patients; lung: 2 patients; skin: 2 patients; kidney: 1 patient; and liver: 1 patient). MIB1 indices (positive tumor cells per 1,000 tumor cells evaluated x 100) in 20 tumors ranged from 1.3 to 24.2 (mean 11.7). p53 nuclear staining was observed in only 2 of 20 tumors. Follow-up information was available in 21 patients: 6 died of tumor (mean 27 months); 9 are alive with residual tumor (mean 35 months); 5 are alive with no evidence of tumor (mean 12 months); and 1 died 13 days postoperatively. There was no obvious correlation of the MIB1 index and tumor behavior. The majority of malignant meningiomas are characterized by nuclear pleomorphism, architectural disorganization, necrosis, prominent nucleoli, and increased mitoses. MIB1 labeling in most malignant meningiomas was high, consistent with the generally rapid growth of these tumors. Only a rare malignant meningioma demonstrated p53 alteration by immunostaining.

Papillary glioneuronal tumor

Tumors of mixed glioneuronal type are well recognized in the central nervous system. The most common examples of these lesions include gangliogliomas and dysembryoplastic neuroepithelial tumors. Recently, unusual examples of these lesions have been described, including the papillary glioneuronal tumor. This report describes a histologically similar-appearing lesion arising in the left parieto-occipital lobe of an 18-year-old man who presented with headaches and difficulties with vision. Imaging studies noted a large cystic neoplasm marked by a peripheral rim of enhancement. The patient underwent gross total resection of the tumor, which histologically was marked by a mixture of glial (glial fibrillary acidic protein-positive) and neural (synaptophysin-positive) components. Architecturally, the tumor was notable for a focal pseudopapillary pattern. Papillae were lined by predominantly glial cells, with intervening areas occupied by neurally differentiated cells. Mitotic activity, vascular proliferation, and necrosis were not noted. A MIB-1 labeling index of 1.1% was seen. p53 immunoreactivity was not observed. This report adds further evidence supporting the existence of this unusual mixed glioneuronal tumor of the central nervous system.

Evaluation of epithelial and keratin markers in glioblastoma multiforme: an immunohistochemical study

OBJECTIVE

Poorly differentiated metastatic carcinoma may be difficult to distinguish histologically from high-grade astrocytic malignant neoplasms, particularly on small open or stereotactic biopsy specimens. Previous authors have reported that a subset of glioblastoma multiforme (GBM) variably stains with cytokeratin immunomarkers. The authors examined a panel of epithelial and keratin antibodies by paraffin immunohistochemistry to evaluate the immunophenotype of GBM for these markers and to determine what combination of immunostains would be optimal in distinguishing GBM from metastatic carcinoma.

METHODS

Twenty-three patients with GBM (age range, 19-86 years; mean, 63.4 years; 14 men and 9 women) and 22 patients with metastatic carcinoma (age range, 26-77 years; mean, 58.1 years; 7 men and 15 women) to the brain were studied with a panel of immunostains, including glial fibrillary acid protein (GFAP), Ber-EP4, antikeratin monoclonal antibodies AE1/3, and antibodies to CAM 5.2 and cytokeratins 7 (CK7) and 20 (CK20). Sites of origin for the metastatic tumors included lung (n = 11), breast (n = 5), endometrium (n = 1), prostate (n = 1), colon (n = 1), presumed kidney (n = 1), and unknown (n = 2).

RESULTS

All GBMs stained positive for GFAP (100%), and all but 1 (95.7%) stained positive for cytokeratins AE1/3. Only rare focal immunoreactivity was observed in a single case of GBM with CAM 5.2 (4.3%), CK7 (4.3%), and CK20 (4.3%). Immunoreactivity with Ber-EP4 was not observed in any of the GBMs (0.0%). All cases of metastatic carcinoma stained positive with cytokeratins AE1/3 (100%) and CAM 5.2 (100%). Variable staining was observed in carcinomas with CK7 (17 of 22, 77.3%), Ber-EP4 (11 of 22, 50.0%), and CK20 (9 of 22, 40.9%). Three metastatic carcinomas showed rare GFAP-positive staining cells (13.6%).

CONCLUSIONS

Based on the aforementioned results, a combination of immunostains, including GFAP and cytokeratin CAM5.2, may be the most useful in differentiating poorly differentiated metastatic carcinoma from GBM. A significant number of GBMs stain with some cytokeratin markers, in particular cytokeratins AE1/3. Because of the poor specificity of cytokeratins AE1/3 in distinguishing metastatic carcinoma from GBM, it should not be used to differentiate the 2 entities.