Cryoultramicrotomy: electrostatic transfer of dry ultrathin frozen sections on grids applied to the central nervous system.

Due to the extreme fragility of ultrathin frozen sections of brain tissue, the cryoultramicrotomy of non-embedded tissue has not been sufficiently used for immunocytochemical studies of the central nervous system. Sections are easily disrupted by the liquid surface tension when a droplet of sucrose is used (method by Tokuyasu, 1973) for their transfer on the grids. Use of silicotungstic acid (Tsuji, 1986) in place of sucrose improved the preservation of the ultrastructure but still could not resolve the difficulty. This report describes a new procedure for transferring dry ultrathin frozen sections by means of electrostatic attraction induced on the membrane covering the grids. Once attached electrostatically to the membrane, the sections were retained by van der Waals' forces. The dry ultrathin frozen sections obtained from both fresh and fixed brains displayed good preservation of their ultrastructures over a large surface. This new method which electrostatically transfers dry ultrathin frozen sections, avoiding the use of any liquid, is expected to serve for the immunocytochemical identification of neuronal cell bodies and terminals as well as their neurotransmitters and enzymes in both fresh and fixed brains.     

Utility of intra-operative consultations for the diagnosis of central nervous system lesions

The inherent soft nature of the central nervous system (CNS) renders poor-quality frozen sections. Cytology has been shown to be of great value in intra-operative consultations of CNS pathology. The current study was undertaken to examine the utility of intra-operative consultations regarding CNS lesions, comparing the usefulness and limitations of frozen section and cytology techniques. A retrospective study of 103 cases of CNS intra-operative consultations was performed. Concordance between the intra-operative diagnosis and the final diagnosis was seen in 94% of cases. Most discrepancies were due to failure to recognize atypia in meningiomas. The cytology technique was more useful for astrocytomas, small round cell tumors, and certain metastases. The frozen section technique was better for the diagnosis of meningiomas, reactive lesions, ependymomas, and most metastatic lesions. Using a combination of the two techniques is most beneficial.     

Immunophenotyping of non-Hodgkin's lymphomas in paraffin-embedded tissue sections. A comparison with genotypic analysis.

Several monoclonal antibodies (MoAbs) are now available for immunophenotyping non-Hodgkin's lymphomas (NHLs) in paraffin-embedded tissue sections. To determine the reliability of these reagents in predicting the genotype, 44 cases of NHL were studied with the alkaline phosphatase-anti-alkaline phosphatase technique with the use of the following MoAbs: leukocyte common antigen (CD45), Mac 387, L26, 4KB5, MB1, MB2, LN2, UCHL1, MT1, and MT2. The lineage of the neoplastic cells was determined in all cases by gene rearrangement studies for immunoglobulin heavy chain and for the T-cell receptor beta-chain. Genotypic results showed B-cell lineage in 33 cases (75%), T-cell lineage in 6 cases (14%), and mixed or undetermined lineage in 5 cases (11%). A concordance of lineage assignment by paraffin section immunophenotyping with gene rearrangement studies was observed in 37 of 39 (95%) lymphomas with an unequivocally defined genotype. MoAb L26 was the most sensitive in detecting B-cell genotype; MoAbs MT1 and UCHL1 were the most sensitive and specific, respectively, in detecting T-cell genotype. The authors conclude that lineage assignment of NHLs in paraffin sections is reflective of the corresponding genotype when an appropriate panel of MoAbs is used.     

A study of intraoperative rapid frozen section diagnosis focusing on accuracy and quality assessment]

Accuracy of frozen section (FS) diagnoses was investigated in a consecutive series of 1129 intraoperative consultations. In our series, the correct diagnosis including clinically not serious minor errors was made in 96.9% of the cases. Whereas the accuracy ratio of FS diagnosis for unknown pathologic process decreased to 92.2%. Among all the types of tissues, central nervous system was shown to be the most frequently handled for FS, followed by lung/bronchus, breast, liver/biliary tract, lymph node and so forth. The requesting ratio of FS, on the other hand, tended to be high in the following specialties; neurosurgery (46.5%), thoracic surgery (19.0%), general surgery, (10.0%). Deferred diagnosis with a provisional diagnosis and misinterpretations in histology typing without serious clinical problem accounted for 2.7% and 3.1% respectively. Causes of erroneous diagnoses seemed to be multifactorial, such as inappropriate sampling, diagnosis on poor quality histology sections, lack of clinical information, lack of enough experience in FS practice of pathologists, or a combination of more than two of them, though inevitable cases showing minimal cytological and structural atypia were included. Intraoperative consultation by FS diagnosis is now essential to serve a good quality medication to patients. It is thus necessary that to establish a tight peer review system and also to provide an education program with regard to practice in FS diagnosis particularly for young pathologists.     

The use of neuroimaging to guide the histologic diagnosis of central nervous system lesions

Recent advances in neuroimaging techniques, particularly in magnetic resonance imaging, have led to substantially improved spatial anatomic resolution such that subtle or small central nervous system lesions, which could go undetected on gross examination of brain sections, are now readily identified on imaging. Although neuroimaging is generally considered the surrogate of gross neuropathology, it is still not a substitute for tissue diagnosis. Rather, it can be a valuable tool for the surgical pathologist in the process of formulating a differential diagnosis based on location and imaging features, as well as in identifying radiologic/pathologic discordance, such as the possible undersampling of a heterogenous glioma, which could lead to underestimation of the tumor grade. The following review focuses on the application of neuroimaging techniques, mainly magnetic resonance imaging, to the histologic diagnosis of central nervous system lesions, and the correlation of imaging features of infiltrative gliomas with histologic findings pertinent to tumor grading. The use of advanced functional magnetic resonance methods, specifically diffusion-weighted imaging, perfusion-weighted imaging, and magnetic resonance spectroscopy is also discussed, as well as the common pitfalls in imaging interpretation.     

Role of cytology and frozen sections in the intraoperative examination of the thyroid: comparison of two experiences

Two experiences of peroperative diagnosis in thyroid surgery are reported. In Bordeaux (France), frozen sections are supplemented by touch smears. Imprints alone give results similar to frozen but are not suitable in differentiating follicular adenoma from carcinoma; they appear more accurate for recognising the follicular presentation of papillary carcinoma. Touch smear is a rapid cost-effective alternative to frozen section. In Brussels (Belgium), a more conventional attitude results in 185 frozen. A false negative ends in a follicular carcinoma. Eleven follicular proliferations will be signed out adenoma (8 cases) or carcinoma (3 cases) and three papillary carcinomas will only be detected after embedding. Six false negative derive from frozen section, no false positive is noted. An immediate change in the surgical procedure is justified twice. These observations argue for the free choice by the pathologist of the best technical procedure in peroperative diagnosis.     

Diagnosis of herpetic lesions of the central nervous system

The results of the use of the two new methods for early diagnosis of herpes simplex virus infection based on immuno-mediated hemagglutination and hemadsorption are presented. In these methods, staphylococcal diagnostic preparations with two kinds of adsorbed antibody are used which allow the presence of the virus to be detected and simultaneously identified. These tests help to detect virus both in the liquid phase at 1-8 days after the onset of the study (immune competition test) and in infected culture cells within the first few days postinfection and long before the appearance of marked cytopathic effect (immune hemadsorption tect). The employment of these methods for the diagnosis of herpetic affection of the central nervous system in children increases by 10-15% the rate of detection of herpes simplex virus with simultaneous identification of the virus.     

乳腺肿瘤冷冻切片诊断中快速EliVision技术的价值

目的探讨快速免疫组化技术（immunohistochemistry,IHC）在乳腺肿瘤术中冷冻病理诊断中的应用价值。方法采用EliVision快速IHC技术检测乳腺肿瘤冷冻切片中常用抗体（SMA、CK5／6、p63、c—erbB一2、CD34、CD117、ER、PR）的表达情况,以相应病例冷冻切片的EliVision常规IHC法以及冰余组织EliVision常规免疫组化法作对照。结果EliVision快速IHC免疫组化法在30min内完成检测,7种抗体显示明确而定位可靠的阳性表达结果（c—erbB-2仅在常规IHC中表达）,阳性率及阳性强度高于相应病例冷冻切片的EliVision常规IHC法、接近于冰余组织EliVision常规IHC法。结论EliVision快速IHC技术可以作为乳腺肿瘤术中冷冻切片病理诊断中有价值的辅助手段。     

Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system

The authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure.     

The paranodal axo-glial junction in the central nervous system studied with thin sections and freeze-fracture

The lateral belts of the myelin sheath wind helically around the paranodal region of the axon. The lateral belt coil leaves an imprint on the axon and thus confers a conspicuous, indented configuration to the freeze-fracture faces of the axolemma. The contact area between the axolemma and the lateral belt membrane is the site of an extensive and unusual cell junction (axo-glial junction). In thin sections the junctional membranes are undulated, the peaks in one membrane mirroring the peaks in the other. The transverse bands (intercellular septa) are in register with the undulations. The intercellular space measures about 30 A. In freeze-fracture replicas, the undulations are evident as alternating ridges and grooves which run strictly parallel and are oriented at an angle with respect to the helical path of the lateral belt. Both junctional membranes contain parallel rows of intramembrane particles which coincide with the ridges and grooves and, therefore, with the intercellular septa. The center-to-center distance between septa or, equivalently, between adjacent rows of particles measures approximately 250 A. Although the axo-glial junction possesses structurally symmetrical features, there exist important differences between the two junctional membranes. The intramembrane particles of the glial and the axonal membrane differ in cleaving properties. Furthermore, in some of the fibres the E face of the junctional axolemma displays a crystalline array which is not present in the fracture faces of the glial membrane. The axo-glial junction is limited to the paranodal region, although the inner belt of the myelin sheath may form occasional junctional spots with the internodal region proper of the axolemma. The classification and the presumptive functions of the paranodal axo-glial junction are briefly discussed.     

Immunoperoxidase labelled antibody staining in differential diagnosis of central nervous system haemangioblastomas and central nervous system metastases of renal carcinomas.

The problem of the differential diagnosis both of central nervous system haemangioblastomas and metastases of renal clear cell carcinomas was investigated by immunoperoxidase labelled antibody staining of five cases each of haemangioblastoma and metastatic renal carcinoma. Staining using anticarcinoembryonic antigen (CEA), antikeratin, antifactor VIII related antigen, and antibrush border was unhelpful. All five of the haemangioblastomas were negative and all five of the metastases were positive for epithelial membrane antigen (EMA), as defined by immunoperoxidase staining. This shows that commercially available anti-EMA monoclonal antibody is useful in distinguishing the two pathological entities.     

Touch imprints in the intraoperative diagnosis of anterior mediastinal neoplasms

OBJECTIVE: To evaluate the accuracy of intraoperative diagnosis of mediastinal lesions using touch imprints and frozen sections. DESIGN: We studied touch imprints and frozen sections from 21 anterior mediastinal lesions retrospectively. The lesions included six cases of non-Hodgkin's lymphoma, eight thymomas, two thymic carcinomas, three Hodgkin's disease cases, and two seminomas. Slides were reviewed independently by each of the three authors, and diagnoses were recorded. RESULTS: Depending on the observer, the correct diagnosis was obtained on touch imprints alone in 76% to 81% of cases. On frozen sections alone, the correct diagnosis was made in 67% to 86% of cases. In 86% to 100% of cases, the correct diagnosis was made on either touch imprint or frozen section. CONCLUSIONS: As with frozen sections, the most common significant error in interpreting cytology preparations was in distinguishing thymic epithelial tumors (thymoma and thymic carcinoma) from lymphoma. On a modified Wright-Giemsa-stained imprint, epithelial cells in a thymoma may be inconspicuous. Clues to their presence include cells with a spindled nuclear shape or a small distinct nucleolus. The epithelial cells have scant cytoplasm with indistinct cell borders. Clumping of cells is often not prominent in lymphocytic thymomas, but may be present in epithelial or mixed lymphocytic and epithelial tumors. With practice, one can learn to recognize thymic epithelial cells on touch imprints. Familiarity with this simple inexpensive technique could improve the accuracy of intraoperative diagnosis of anterior mediastinal lesions.     

Oral motor deficits following lesions of the central nervous system in the rat.

The effects of lesions of the zona incerta (ZI), globus pallidus (GP), midlateral and far lateral hypothalamus (MLH and FLH), and the central amygdaloid complex (CAC) on oral motor deficits were investigated. Lesions of the ZI, GP, and CAC resulted in a significant reduction in tongue extension and lap volume. MLH lesions significantly reduced tongue extension whereas FLH lesions significantly reduced both tongue extension and lap volume. Injections of 6-hydroxydopamine into the GP, MLH, and CAC also significantly reduced tongue extension and lap volume. Water and/or food intakes were reduced in some of the lesioned groups but the oral motor deficits were observed both in the presence and in the absence of reduced water and food intakes. The possibility that oral motor deficits are associated with damage to striatal and non-striatal dopamine neurons needs further investigation.     

Lipocortin-1 immunoreactivity in the normal human central nervous system and lesions with astrocytosis

The authors have examined the cellular distribution of lipocortin-1 (L-1) in the normal and diseased central nervous system (CNS) using the peroxidase-antiperoxidase (PAP) technique with a polyclonal antibody specific for L-1. L-1 immunoreactivity was evaluated in the frontal cortex, parahippocampal gyrus/lateral ventricle, cerebellum, medulla, and spinal cord from 27 normal human fetuses, neonates, and adults without neurologic disease and in these same regions and representative lesions from 35 patients with diseases producing varying degrees of astrocytosis, including intraparenchymal hemorrhage; embolic, thrombotic, or traumatic infarctions; and Alzheimer's disease (AD). L-1 immunoreactivity was identified in ependymocytes, choroid plexus epithelia, and scattered subependymal astrocytes throughout the ventricular system from 15 weeks gestation through 82 years of age in both normal and diseased CNSs. L-1 immunoreactivity was also detected in reactive astrocytes and many macrophages surrounding each infarction regardless of site or pathogenesis and in scattered reactive astrocytes in people with AD or SDAT. The limited distribution of L-1 in CNS is consistent with the low amounts of L-1 found in brain and suggests that L-1 may participate in the normal function of ependymocytes and the pathophysiology of reactive astrocytosis.