[Bodies scorned: when medicine and caricature meet]

With the advent of the illustrated press, in 1840, the art of caricature initiated an interesting dialogue with historical painting and portraiture. The article shows dr. Oswaldo Cruz as target of this humorous language in the early twentieth century. Caricature -- a line that cries out -- recognizes the pain of its injured subject and, under an unwritten intersubjective pact, uses humor to release the violence of suffered aggression.

Insulin-like growth factor-1 content and pattern of expression correlates with histopathologic grade in diffusely infiltrating astrocytomas

Studies of experimental tumorigenesis have strongly implicated signaling of the insulin-like growth factor 1 (IGF-1) as a key component in astrocytic neoplasia; however, its role in the growth of low-grade and malignant human tumors is not well understood. Correlative analyses of IGF-1, p53, and Ki-67 (MIB-1) immunohistochemistry and IGF-1 receptor (IGF-1R) mRNA expression were performed to examine the cellular pattern of IGF-1 signaling in 39 cases of astrocytoma (World Health Organization grades II-IV). Tumor cells expressing IGF-1 and IGF-1R were present in all tumor grades. The proportion of tumor cells that expressed IGF-1 correlated with both histopathologic grade and Ki-67 labeling indices, while expression of IGF-1R mRNA correlated with Ki-67 indices. In cases where stereotactic tissue sampling could be identified with a specific tumor area by neuroimaging features, the numbers of IGF-1 immunoreactive cells correlated with the tumor zones of highest cellularity and Ki-67 labeling. In glioblastomas, the localization of IGF-1 immunoreactivity was notable for several features: frequent accentuation in the perivascular tumor cells surrounding microvascular hyperplasia; increased levels in reactive astrocytes at the margins of tumor infiltration; and selective expression in microvascular cells exhibiting endothelial/pericytic hyperplasia. IGF-1R expression was particularly prominent in tumor cells adjacent to both microvascular hyperplasia and palisading necrosis. These data suggest that IGF-1 signaling occurs early in astroglial tumorigenesis in the setting of cell proliferation. The distinctive correlative patterns of IGF-1 and IGF-1R expression in glioblastomas also suggest that IGF-1 signaling has an association with the development of malignant phenotypes related to aberrant angiogenesis and invasive tumor interactions with reactive brain.

Control of primary angiitis of the CNS associated with cerebral amyloid angiopathy by cyclophosphamide alone

Corticosteroids combined with cyclophosphamide are currently recommended for primary angiitis of the CNS. The authors report a 71-year-old man with primary angiitis of the CNS and amyloid angiopathy who responded to cyclophosphamide without steroids, suggesting that corticosteroids may not be needed in all cases of primary angiitis of the CNS.

Estrogen receptors in prolactinomas: a clinico-pathological study

BACKGROUND

Antiestrogens are effective in the treatment of estrogen receptor (ER) positive breast carcinoma. The use of antiestrogen therapy in pituitary adenomas, however, has not been explored. This study attempted to identify a population who may benefit from antiestrogen therapy.

MATERIALS & METHODS

Prolactinomas from 29 patients (10 men, 19 women) were analyzed for ER and Ki-67 labeling index using immunohistochemistry. Nine of the 19 women were either amenorrheic or had not received exogenous estrogen for at least one year. Ten women were menstruating either spontaneously or as a result of estrogen administration. Factors including age, serum prolactin level, tumor size, evidence of tumor invasiveness and recurrence of tumor were evaluated to determine if they were predictive of ER expression.

RESULTS

Tumors from 6/10 (60%) men were positive for ER. Among women who were having menses, 9/10 (90%) tumors were positive, whereas 6/9 (67%) tumors from amenorrheic women were positive. Statistical analysis revealed that none of the variables: gender, age, menstrual status, Ki-67 proliferative rate, exposure to dopamine agonists, preoperative prolactin level, tumor size, or invasiveness was predictive for the presence of the receptor. The incidence of ER, however, was significantly reduced in recurrent tumors (p = 0.03).

CONCLUSIONS

ER expression is less likely in recurrent tumors. The efficacy of ER antagonists cannot be inferred by gender or estrogen exposure.

Selective expression of estrogen receptor alpha and beta isoforms in human pituitary tumors

The physiological effects of estrogen on the pituitary, including cellular proliferation and regulation of hormone synthesis, are mediated by the nuclear estrogen receptor (ER). The ER acts as a dimer to modulate gene transcription and contains specific functional domains encoded in different exons. Two separate, but related, forms of the receptor (ERalpha and ERbeta) exist, with distinct tissue and cell patterns of expression. Additional ER isoforms, generated by alternative messenger ribonucleic acid (mRNA) exon splicing, have been defined in several tissues and are postulated to play a role in tumorigenesis or in modulating the estrogen response. We examined 71 human pituitary adenomas of varying phenotypes and 6 normal pituitary specimens for ER mRNA forms by RT-PCR and hybridization blotting analysis. All prolactinomas (n = 14) contained ERalpha, and several contained ERbeta (5 of 14) mRNA. In comparison, 6 tumors that expressed PRL and GH expressed ERbeta (4 of 6) more frequently than ERalpha (3 of 6). ERbeta mRNA was also found more frequently in null cell (8 of 24 ERalpha and 14 of 24 ERbeta) and gonadotrope (13 of 21 ERalpha and 18 of 21 ERbeta) tumors. Additionally, ERbeta was found in 4 of 6 tumors that contained only GH, although ERalpha was not observed in this tumor type. Expression of the two ER forms within a tumor type was overlapping, but some tumors contained only 1 isoform. Expression of ERalpha mRNA splice variants also varied with cell type. All normal pituitaries contained ERalpha deletions of exon 4, 5, and 7, whereas only 2 of 6 samples contained the exon 2 deletion variant. Although the same ERalpha mRNA variants were observed among the various tumor types, the proportion of specific splice variants expressed varied. For example, most ER-positive prolactinomas expressed ERalpha variants with deletions of exon 2, 4, or 5, whereas gonadotropin tumors preferentially expressed the ERalpha exon 7 deletion variant. A novel ERbeta mRNA splice variant, missing exon 2, was observed in a majority of all ERbeta-positive tumors. Immunoblotting analysis of ERalpha and ERbeta proteins supported the mRNA results. Because ERalpha and ERbeta have different biological responses to selective ER modulators, and the ER deletion variants have biological effects distinct from those of the full-length ER, expression of these isoforms may influence the biological properties of these tumors and affect their ability to respond to estrogen and antiestrogen therapies.

Determination of growth fraction and cell density to evaluate the potential growth of human oligodendroglial and astrocytic tumours

The object of this work was

PURPOSE

to develop a methodology that enables net tumour growth, a balance between actual tumour growth and tumour cell loss, to be approximately evaluated.

METHODS

The methodology proposed relies on detecting the growth fraction immunohistochemically by means of MIB-1 antibody labelling combined with cell density determination, carried out on 5-microm-thick Feulgen-stained histological sections with computer-assisted microscopy. The series investigated included 25 oligodendrogliomas (OLG-II), 9 anaplastic oligodendrogliomas (OLG-III). 13 astrocytomas (AST), 14 anaplastic astrocytomas (ANA) and 8 mixed oligoastrocytomas (OLG-AST).

RESULTS

The results show that the biological characteristics of some cases were in total accordance with their histopathological diagnoses. This was the case for the "weakly proliferating weakly dense" OLG-II and AST-II tumours, and for the "highly proliferating highly dense" OLG-III and AST-III ones. In contrast, the biological characteristics of some cases seemed to contradict the histopathological case labels. This was the case for the "highly proliferating highly dense" OLG-II and AST-II tumours, the biological aggressiveness of which would be undervalued on the basis of the morphology-based grading system alone, and also for the "weakly proliferating weakly dense" OLG-III and AST-III tumours, the aggressiveness of which would be overvalued.

CONCLUSIONS

Combining the determinations of the MIB-1 and the cell density variables appears to be satisfactory in terms of the cell kinetic characterization of glial tumours as a complement to the prognostic information given by a morphology-based grading system alone.

Primary fibrosarcoma of the sella unrelated to previous radiation therapy

Fibrosarcomas involving the sella turcica are rare lesions and, when encountered, have been associated with previous radiation of a pituitary adenoma. Although primary intracranial fibrosarcomas are well recognized, no case of primary fibrosarcoma of the sella turcica has been reported to date. We describe here a patient who presented with a 2-month history of headache, visual disturbances, and diabetes insipidus. Her past medical history was unremarkable, with no radiation therapy. Magnetic resonance imaging revealed a sellar/suprasellar lesion that at surgery appeared firm in consistency. A radical removal of the mass was performed through a transsphenoidal approach. The patient recovered promptly from the operation and 2 weeks later, given the aggressive histologic appearance of the lesion, underwent gamma knife radiosurgery. Seven months after diagnosis, the patient presented with local tumor recurrence. A subtotal surgical resection was performed, and additional postsurgical treatment is still under consideration. Although most often related to previous radiation of the pituitary gland, primary fibrosarcomas can occur in the sella. This possibility should be suspected in the differential diagnosis of sellar masses that lack the classical characteristics of the much more common pituitary adenomas.

Platinum coil-mediated implantation of growth factor-secreting endovascular tissue grafts: an in vivo study

PURPOSE

To demonstrate in vivo that platinum embolic coils can be used to deliver genetically modified, growth factor-secreting fibroblast grafts into the endovascular space with the long-term goal of improving fibrosis within coil-embolized cerebral aneurysms.

MATERIALS AND METHODS

Murine fibroblasts that contained multiple inserts of the DNA for human basic fibroblast growth factor were grown in culture onto 10-mm-long segments of Guglielmi detachable coils. Control (n = 4) and fibroblast-bearing (n = 4) coils were implanted into the common carotid artery in nude rats. The arterial segments that contained the coil were harvested after 14 or 35 days. Cellular content and collagen formation in the treated vessels were assessed histologically.

RESULTS

At both 14 and 35 days, samples with control coils showed primarily involuting blood elements with minimal fibroblast proliferation or collagen formation. At 14 days, samples with fibroblast-bearing coils showed extensive fibroblast proliferation. At 35 days, samples with fibroblast-bearing coils showed marked interval fibroblast proliferation and collagen formation.

CONCLUSION

Platinum coils can be used as a cell delivery device. Direct intravascular implantation of growth factor-secreting fibroblast grafts leads to improved intravascular scar formation, therefore theoretically reducing the potential for aneurysm regrowth or coil compaction.

Sulfonylurea receptor mRNA expression in pituitary macroadenomas

ATP-sensitive K+ (KATP) channels modulated by sulfonylurea compounds have been previously identified in the anterior pituitary of the rat and have been demonstrated to influence GH release. Recently, a sulfonylurea receptor (SUR) has been cloned from an islet cell tumor and identified as a member of the ATP binding cassette superfamily capable to coupling with inwardly rectifying potassium channels. To determine if the same receptor is expressed in pituitary tumors, SUR mRNA levels were measured in 28 human macroadenoma specimens using an RNase protection assay. All immunonegative, corticotrophin (ACTH), growth hormone (GH), and GH/prolactin (GH/Prl) immunostaining tumors expressed detectable amounts of SUR message. Among these tumors, only the GH and GH/ Prl adenomas were functional. Of the tumors immunostaining for luteinizing hormone (LH), follicle-stimulating hormone (FSH), or both, SUR mRNA was present in small amounts in 5/11. Only 1/3 Prl immunostaining tumors contained SUR mRNA. In summary, we have demonstrated that SUR mRNA expression is common in several types of silent pituitary adenomas and in functional tumors that secrete GH. Lower levels are seen in some gonadotrophin immunostaining tumors.

Mature pulmonary lobar transplants grow in an immature environment

OBJECTIVE

Mature lobar transplantation will increase the pediatric donor organ pool, but it remains unknown whether such grafts will grow in a developing recipient and provide adequate long-term support. We hypothesized that a mature pulmonary lobar allograft implanted in an immature recipient would grow.

METHODS

We investigated our hypothesis in a porcine orthotopic left lung transplant model using animals matched by the major histocompatibility complex to minimize the effects of chronic rejection. Twenty-three immature animals (< 12 weeks of age and < 10 kg total body weight) received either sham left thoracotomy (SH control, n = 4), left upper lobectomy to study compensatory growth (UL control, n = 4), age-matched immature whole left lung transplants (IWL TXP, n = 6), mature (donor > 1 yr in age and > 40 kg in total body weight) left lower lobe transplants (MLL TXP, n = 5), or mature left upper lobe transplants (MUL TXP, n = 4). Twelve weeks after implantation, functional residual capacity of the left lung was measured and arterial blood gas samples were obtained after the native right lung had been excluded. The graft was excised and weighed, and samples for microscopy and wet/dry ratios were collected.

RESULTS

Initial and final graft weights were as follows: IWL TXP group (34.6 +/- 1.5 and 107.8 +/- 5.9 gm, p < 0.0001), MLL TXP group (72.4 +/- 6.8 and 111.4 +/- 8.7, p < 0.001), and MUL TXP group (32.8 +/- 1.3 and 92.8 +/- 7.1 gm, respectively, p < 0.004). No significant differences between groups were demonstrated when functional residual capacity, wet/dry ratios, or oxygenation were compared. Immunohistochemical staining for the nuclear antigen Ki-67 demonstrated dividing pneumocytes.

CONCLUSIONS

We conclude that a mature lobar graft implanted into an immature recipient grows by pneumocyte division in this model. Mature lobar transplants can be expected to grow and provide adequate long-term function in developing recipients.

Growth hormone-releasing hormone receptor mRNA in acromegalic pituitary tumors

The growth hormone (GH)-releasing hormone receptor (GHRH-R) has been recently cloned and found to be a member of a new family of seven transmembrane receptors that includes secretin, vasoactive intestinal peptide, calcitonin, and corticotropin-releasing factor. GHRH-R mRNA has been demonstrated by Northern blot analyses to be present specifically in the anterior pituitary gland. To determine the precise cellular localization of this receptor in normal anterior pituitary and pituitary adenomas, GHRH-R mRNA was analyzed in 2 normal human pituitary glands and 16 human pituitary adenomas using in situ hybridization. GHRH-R was specifically localized in somatotroph cells in the normal pituitary. In the adenomas, all GH-producing adenomas originating from acromegalic patients demonstrated up-regulation of GHRH-R mRNA when compared with levels in the normal pituitary. Only one of five clinically nonfunctioning adenomas, a gonadotroph luteinizing hormone/follicle-stimulating hormone-positive adenoma, exhibited up-regulation of this receptor message. Adrenocorticotrophic hormone-secreting and prolactin-secreting adenomas did not express GHRH-R message. In summary, GHRH-R is specifically expressed in somatotrophs and GH-producing adenomas, suggesting that GHRH-R may influence GH release in adenomas similar to this receptor's actions in the normal somatotrophs and may be involved in the growth of GH-secreting adenomas.

Ganglioglioma: an ultrastructural and immunohistochemical study

BACKGROUND

Ganglioglioma is a rare, mixed neuronal-glial neoplasm of the central nervous system that occurs in young patients and has a benign clinical course.

METHODS

To define the immunophenotypic and morphologic features of ganglioglioma precisely, 27 specimens were studied by routine histochemistry, 21 specimens by immunochemistry, and 14 specimens were examined at the ultrastructural level.

RESULTS

The age of the 27 patients, 14 males and 13 females, ranged from 3 to 52 years (mean, 22 years). The most commonly affected site was the temporal lobe (13 patients). Three patients experienced a local recurrence. Microscopically, the tumors were comprised of well differentiated, somewhat abnormal neurons as well as glial cells, the latter including astrocytes of fibrillary (59%) and pilocytic (41%) type. Scant mitotic activity was observed in 2 tumors (7%). Glial cells of all tumors were immunoreactive for glial fibrillary acidic protein, S-100 protein, and vimentin. Ki-67 labeling indices (LI) ranged from 0.6 to 10.5% (mean, 2.7%) and p53 LI from 1.1 to 42.4% (mean, 15.6%). Ki-67 and p53 LI in recurrent tumors were significantly higher than those of nonrecurrent ones (P = 0.036 and 0.026, respectively). No examples of anaplastic transformation were encountered. Immunohistochemically, many neuronal cells were positive for synaptophysin (100%), Class 3 beta-tubulin (100%), neurofilament protein (90%), and chromogranin A (86%), in addition to S-100 protein (71%) and, occasionally, vimentin (24%). Ultrastructural characteristics of neuronal cells included the presence of numerous, 100-230-nanometer dense core granules within both perikarya and cell processes, well developed rough endoplasmic reticulum, microtubules within cell processes, and synapses associated with clear vesicles. Astrocytic cells usually contained abundant intermediate filaments; their cell membranes, when abutting the stroma, were covered by basal lamina.

CONCLUSIONS

Gangliogliomas are comprised of well differentiated neuronal cells and glial cells that are very often of pilocytic type. No cells with features intermediate between neurons and glia were observed. Neuronal cells are characterized by prominent neurosecretory features distinct from those of normal neurons in the central nervous system. Higher Ki-67 and p53 LI may indicate more aggressive behavior.

Maturation of intracranial immature teratomas. Report of two cases

Immature teratomas arising within the central neuraxis are rare neoplasms. These tumors contain diverse cell lineages that retain an embryonal character and display phenotypic differentiation attributed to the three classic germ layers. The clinical management of these lesions is unclear, due in part to their low incidence and to an incomplete understanding of their natural history. Although the potential for phenotypic differentiation and cellular maturation within immature teratomas arising in the gonads is well documented, this has not been described in the intracranial tumors. In the present report, the authors describe two cases of intracranial immature teratomas, one involving the pineal region and the other involving the left frontotemporal lobes, which underwent cellular differentiation and maturation. At initial resection, the tumors from both cases were composed predominantly of primitive neuroepithelial tissue that was admixed with immature and differentiating mesenchymal and epithelial structures. No foci of germinoma, endodermal sinus, choriocarcinoma, or embryonal carcinoma tissue were present. Subsequent resections in both cases revealed an absence of immature tissue. The tumor in Case 1 contained only differentiated epithelial and mesenchymal tissue with no neuroepithelial component, whereas the tumor in Case 2 demonstrated abundant mature neuronal and glial tissue. These two cases from different intracranial sites suggest that spontaneous maturation may be a significant aspect of the natural history of intracranial immature teratomas.

Occlusion of the anterior cerebral artery after Gamma Knife irradiation in a rat

The anterior cerebral artery of rats was irradiated at the level of the circle of Willis by Gamma Knife with a maximum dose of 25, 50, or 100 Gy. Occlusion of the anterior cerebral artery was observed in one rat which was followed for 20 months after irradiation of 100 Gy. Cerebral infarction was found at the midline-frontal region and the cingulate gyrus. Arterial wall thickening with fibrosis, splitting of the internal elastic membrane, luminal organized thrombus, and migration of smooth muscle cells into the thrombus were observed. In the anterior cerebral artery, thrombus formation seemed to occur after the endothelial injury and this may play a prominent role for occlusion. In small arteries, various changes were observed in the irradiated tissue. These included fibrosis and thrombus, thickened smooth muscle layer, lymphocytic infiltration, and thickening of vessel wall with fibrosis and fibrinous thrombosis with leakage of fibrin into the surrounding tissue after different doses of radiation and at different observation times. These changes were comparable to the ordinary vascular response to injury including healing vasculitis and arteriosclerosis.

Histological changes in the normal rat brain after gamma irradiation

Radiation-induced changes in the parietal cortex of Wistar rats were observed at various time points after gamma surgery. Maximum dosages of 50, 75, and 120 Gy were given at the iso-center of the radiation using a 4-mm collimator. Conventional histochemical and immunocytochemical analyses, and computer-assisted videomicroscopy were utilized to examine perfusion-fixed brain tissue. Irradiation at a dosage of 50 Gy elicited morphological changes of astrocytes in the parietal cortex at 3 months. Vasodilatation became obvious at 12 months; fibrin deposition was observed in the dilated capillary wall. Neither leakage of Evans Blue from the vasculature into the tissue nor necrosis was observed across the 12 month observation period. Irradiation at a dosage of 75 Gy resulted in morphological changes of astrocytes within 1 month. Dilatation of vessels and capillary thickening were observed at 3 months. Evans Blue leakage and necrosis were observed at 4 months after 75 Gy irradiation. At this time, the walls of arterioles became thickened by subintimal accumulation of fibrin and hyaline substance; this sometimes resulted in occlusion of the lumen. Significant hemispheric swelling was observed at 4 months. Irradiation at a dosage of 120 Gy elicited changes in astrocytic morphology within 3 days. Evans Blue leakage into the tissue was observed by 3 weeks. Vasodilation became marked at this time point and rarefaction was observed in the irradiated cortex. Necrosis was observed at 4 weeks, however, no significant swelling was observed. Taken together, these findings demonstrate time-dependent and dosage-dependent changes in normal cerebral tissue after Gamma Knife irradiation. These results provide a basis for gauging the impact of gamma surgery in regions of eloquent tissue. An enhanced understanding of the cellular responses to radiosurgery will contribute to developing and evaluating future applications for gamma surgery.

Immunohistochemical characterization of subependymal giant cell astrocytomas

Subependymal giant cell astrocytoma (SEGA) is the most common neoplastic process involving the brain in patients with tuberous sclerosis complex (TSC). Morphologically, these tumors exhibit a wide range of cytoarchitecture with spindle and epithelioid cells resembling astrocytes, and also large, occasionally giant cells, some of which have a distinctly ganglion-like appearance. Unresolved questions regarding SEGAs center on: (a) their cytogenesis, i.e., whether they are derived from single or multiple precursors; and (b) their differentiating capacity along glial or neuronal lines. We sought to determine whether SEGAs represent truly mixed tumors or whether they consist of a single population of cells with a capacity for divergent differentiation. Twenty SEGAs were assessed for immunophenotypic features of either neuronal or glial differentiation or both. Only tumors from patients with a clinically confirmed diagnosis of TSC were included. Immunoreactivity for glial fibrillary acidic protein (GFAP) and/or S-100 protein was considered indicative of a glial phenotype, whereas the presence of neuronal differentiation was assessed by staining for cytoskeletal proteins [neurofilament epitopes, class III Beta-tubulin, microtubule-associated protein 2 (MAP2), synaptophysin], neurosecretory substances [serotonin, cholecystokinin, Beta-endorphin, substance P, somatostatin, metenkephalin, neuropeptide Y, vasoactive intestinal polypeptide (VIP), and for the 28-kDa neuron-associated calcium binding protein calbindin. Of the tumors examined, 18 exhibited both glial and neuronal epitopes, the staining pattern being variable. In 19 tumors, the constituent spindle, polygonal and giant or ganglion-like cells showed variable immunoreactivity for GFAP and S-100 proteins both within the cell body and processes. Neuron-associated cytoskeletal proteins were present in 18 cases. Class III Beta-tubulin immunoreactivity was demonstrated in 17 tumors, both within the bodies of all three cell types and to varying degrees within their processes. Neurofilament protein and calbindin staining was present in 8 tumors, with reactivity for the former being distributed in a phosphorylation-dependent manner. MAP2 was detected in a few cells of two tumors. Immunoreactivity for neuropeptides was observed in 17 lesions. Somatostatin and metenkephalin staining was noted in 10 tumors (50%) being present particularly within polygonal cells. Neuropeptide Y, serotonin and Beta-endorphin reactivity was found in 6 (30%), 5 (25%), and 4 tumors (20%), respectively; Beta-endorphin was lacking in giant cells, whereas neuropeptide Y and serotonin were seen within their cell bodies. Substance P and VIP were evident in only occasional polygonal cells of 2 (10%) and 1 tumor (5%), respectively. Stains for cholecystokinin were negative. The observation of immunoreactivity for both glial- and neuron-associated epitopes within tumor cells of the same morphology suggests that SEGAs represent proliferations of cell lineages with the capacity to undergo divergent glioneuronal as well as neuroendocrine differentiation to a greater extent than do other mixed glial-neuronal neoplasms.

Alzheimer's disease in a case of cortical basal ganglionic degeneration with severe dementia

Images

1995 AUR Memorial Award. Gamma knife irradiation-induced changes in the normal rat brain studied with 1H magnetic resonance spectroscopy and imaging

RATIONALE AND OBJECTIVES

The pathogenesis of brain injury following radiosurgery is poorly understood. To better elucidate the relationship between blood-brain barrier disruption and metabolic derangements, we used magnetic resonance (MR) imaging and 1H MR spectroscopy to detect early changes from focused single-fraction, high-dose irradiation injury in rat brains.

METHODS

Using the Leksell gamma knife, we irradiated the frontoparietal cortex of 11 male Wistar rats with a single dose of 120 Gy. Four weeks later, we sequentially performed water-suppressed 1H MR spectroscopy and gadopentetate dimeglumine-enhanced T1-weighted MR imaging. Metabolic maps were created of n-acetylaspartate (NAA), creatine and choline (Cr/Cho), and lactate from the MR spectroscopy data set. Detection of irradiation injury among the tested modalities was assessed by receiver operating characteristic analysis and by quantitative signal intensity changes. Pathologic confirmation of irradiation damage was obtained in all rats.

RESULTS

Gadopentetate dimeglumine-enhanced T1-weighted MR imaging was the only imaging modality that detected statistically significant signal intensity changes (p < .05). No reproducible changes in the metabolites of interest could be detected by 1H MR spectroscopy.

CONCLUSION

In our animal model, blood-brain barrier disruption was a reproducible, integral finding of single-fraction, high-dose irradiation injury. No reproducible metabolic derangements of ischemia or necrosis were detected by 1H MR spectroscopy, possibly because of dose-latency effects or sensitivity issues.

Tuber and subependymal giant cell astrocytoma associated with tuberous sclerosis: an immunohistochemical, ultrastructural, and immunoelectron and microscopic study

The cellular nature of the giant eosinophilic cells of tuber and of the cells comprising subependymal giant cell astrocytoma (SEGA) in tuberous sclerosis (TS) remains unclear. To assess the characteristics of these lesions, 13 tubers and 6 SEGA were immunohistochemically studied with glial and neuron-associated antigens. In addition to conventional ultrastructure, 6 tubers and 8 SEGA were subjected to immunoelectron microscopic study for glial fibrillary acidic protein (GFAP) and somatostatin. Eosinophilic giant cells of tubers were positive for vimentin (100%), GFAP (77%) and S-100 protein (92%); such cells were also found to a various extent to be reactive for neuron-associated antigens, including neurofilament (NF) proteins (38%) or class III beta-tubulin (77%). SEGA also showed variable immunoreactivity for GFAP (50%) or for S-100 protein (100%); NF epitopes, class III beta-tubulin, and calbindin 28-kD were expressed in 2 (33%), 5 (83%) and 4 (67%) cases, respectively. Cytoplasmic staining for somatostatin (50%), met-enkephalin (50%), 5-hydroxytryptamine (33%), beta-endorphin (33%) and neuropeptide Y (17%) was noted in SEGA, but not in tubers. Ultrastructurally, the giant cells of tubers and the cells of SEGA contained numerous intermediate filaments, frequent lysosomes and occasional rectangular or rhomboid membrane-bound crystalloids exhibiting lamellar periodicity and structural transition to lysosomes. Some SEGA cells showed features suggestive of neuronal differentiation, including stacks of rough endoplasmic reticulum, occasional microtubules and a few dense-core granules. Furthermore, in one case of tuber, a process of a single large cell was seen to be engaged in synapse formation. Intermediate filaments within a few cells of both lesions were decorated by gold particle-labeled GFAP antiserum. Within the tumor cells of SEGA, irregular, non-membrane-bound, electron-lucent areas often contained somatostatin-immunoreactive particles, whereas the latter could not be detected in tuber. The present study provides further evidence of divergent glioneuronal differentiation, both in the giant cells of tubers and the cells of SEGA. The findings of similar cells at different sites, including the subependymal zone, white matter ("heterotopias"), and cortex indirectly supports the idea that these lesions of TS result from a migration abnormality.

Failure in management of pituitary tumors discussion of 3 cases

Three patients with pituitary adenomas (ACTH-secreting, non-secretory, and multi-secretory) with unfavorable course, in spite of repeated microsurgery, drug therapy, as well as radiotherapy and radiosurgery, are presented. Each case was re-evaluated for possible flaws in management. Two of the invasive tumors continued to grow, in spite of correct management. The third patient with a pituitary adenoma underwent microsurgical resection, and later following a false positive finding of recurrence, received radiotherapy and underwent radiosurgery. The lesion actually was chronic inflammatory tissue.

Olfactory neuroblastoma. An immunohistochemical, ultrastructural, and flow cytometric study

BACKGROUND

Olfactory neuroblastoma is an uncommon neuroectodermal tumor of the upper nasal cavity, microscopic features of which are not always homogeneous. No morphologic features have been found to correlate reliably with prognosis.

METHODS

Twenty-six olfactory neuroblastomas occurring in 14 females and 12 males, ages 18-78 years, were studied by immunohistochemistry, electron microscopy, and DNA flow cytometry. Survival rates were statistically analyzed relative to several variables.

RESULTS

Microscopically, 22 tumors formed a morphologic spectrum intermediate between paraganglioma (PG) and neuroblastoma (NB). Others included two ganglioneuroblastomas (GNB), one lesion exhibited biphasic (neuronal and epithelial) differentiation, and one tumor showed predominantly epithelial features. Immunoreactivity for neuronal and neuroendocrine markers included synaptophysin in 77%, neurofilament protein in 38%, class III beta-tubulin in 81%, and chromogranin A in 77%. In 88% of cases, elongated S-100 protein-positive cells surrounded tumor lobules. Cytokeratin and epithelial membrane antigen immunoreactivity were noted in six (23%) and two (8%) tumors, respectively. Aberrant p53 expression was detected in 16 tumors (62%). The Ki-67 labeling index (LI) varied from 0%-43.8% (mean, 7.4%). Ultrastructurally, 80-230 nm dense core granules were noted within perikarya and as in microtubule-containing processes in all of the 11 tumors studied by electromicroscopy. Lobules of seven tumors were surrounded by electron-dense sustentacular cells. Epithelial tumors exhibited obviously epithelial features in addition to neuronal differentiation. DNA flow cytometry demonstrated a high incidence of polyploidy and aneuploidy (78%) and a wide range of percent S phase fractions (1.5%-21.8%; mean, 9.0%). The study showed that longer survival rates are related significantly to (1) the occurrence of metastases which was linked to tumor subtype, (2) to a higher incidence of S-100 protein-positive cells, and (3) to a low (< 10%) Ki-67 labeling index.

CONCLUSIONS

The present study indicates that (1) although typical olfactory neuroblastomas exhibit PG/NB differentiation, they more closely resemble PG, (2) occasional tumors show GNB and/or epithelial differentiation, and (3) survival rates may correlate with S-100 protein immunoreactivity and Ki-67 LI. Cancer 1995; 76:4-19.

Estrogen receptor expression in human pituitary: correlation with immunohistochemistry in normal tissue, and immunohistochemistry and morphology in macroadenomas

Forty-one human pituitary adenoma specimens were examined for the presence of estrogen receptor (ER) messenger ribonucleic acid and protein using a combination of ribonuclease protection assay, [3H] estradiol ([3H]E2) binding, and ER immunohistochemistry. ER messenger ribonucleic acid prevalence was high in PRL-immunoreactive tumors (2 of 2), moderate in GH/PRL tumors (2 of 5), and low or absent (0 of 4) in GH tumors. In the GH/PRL-immunostaining tumors, the presence of the ER was uniformly associated with elevated serum PRL levels. Among the gonadotropin-immunostaining tumors, 10 of 17 were ER positive; within this group, those with gonadotroph adenoma characteristics were ER positive, whereas those with null cell/oncocytic characteristics were ER negative. Of the tumors that did not immunostain for any known anterior pituitary hormones, 3 of 11 were ER positive. ER immunohistochemistry in 14 tumors revealed a 100% correlation with ribonuclease protection assay results, whereas [3H]E2 binding, determined in 9 tumors, showed an 87% correlation. In summary, it appears that PRL and a specific class of gonadotropin-immunostaining tumors (identifiable by specific characteristics on electron microscope) contain ER, whereas GH-immunostaining tumors are ER negative. ER expression in normal pituitary paralleled that in macroadenomas (GH, 2.3%; PRL, 50%; FSH, 70%; LH, 83%; TSH, 4%; ACTH, 1%). The ER-positive tumors represent a subset whose growth and secretory profiles may be influenced by the gonadal steroidal milieu or by pharmacological agents that affect E2 levels or ER function.

Dysembryoplastic neuroeptihelial tumor (DNT): an immunohistochemical and ultrastructural study

To assess the range of differentiation of the cells comprising dysembryoplastic neuroepithelial tumor (DNT), particularly the oligodendrocyte-like cells (OLC), 14 DNT were immunochemically studied with a spectrum of neuronal and glial markers. Eight tumors were also studied ultrastructurally. Neurofilament protein, class III beta-tubulin, and synaptophysin preparations stained a few OLC in two, six and one lesion, respectively. In addition, many OLC within a single cortical nodule were reactive for class III beta-tubulin. The vast majority of OLC were strongly S-100 protein positive. Glial fibrillary acidic protein labeled a fair number of OLC in two cases and one nodule consisted almost entirely of immunoreactive astrocytes. Ultrastructurally, many OLC resembled oligodendrocytes in exhibiting microtubules, prominent Golgi and short cell processes; pericellular lamination of cell processes, a characteristic of oligodendroglia, was noted in only one tumor. In two cases, OLC with astrocytic features were seen to contain small numbers of intermediate filaments. In four cases, a few OLC resembled immature neurons with scant dense-core granules or synapses. This study confirms the glioneuronal nature of DNT, a lesion composed of heterogeneous cells, many resembling oligodendrocytes and a few showing early astrocytic and neuronal differentiation. Although their relation to OLC is unclear, the presence and peculiar distribution of mature neurons is nonetheless an integral diagnostic feature of the lesion.

Expression of alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein is increased in reactive and neoplastic glial cells

alpha 2-Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2M-R/LRP) is a multi-functional cell-surface receptor that has been implicated in diverse physiologic processes. In normal human brain, alpha 2M-R/LRP is expressed principally by pyramidal neurons with localization to cell bodies and proximal processes. By contrast, alpha 2M-R/LRP is not present in either the cell bodies or processes of most normal macroglia (including astrocytes). In this investigation, we studied the expression of alpha 2M-R/LRP in the brain, following tissue injury or neoplastic transformation, by immunohistochemistry. Significantly increased alpha 2M-R/LRP immunoreactivity was identified in reactive astrocytes, indicating the expression of this receptor is regulated in vivo in response to brain injury. alpha 2M-R/LRP immunoreactivity was also detected in glial cell tumors; this finding is novel since malignant transformation is typically thought to turn off expression of this receptor.