Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HISTOLOGY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

[Histological classification of renal cell carcinoma--problems in JUA classification].

BACKGROUND: Although renal cell carcinoma (RCC) is often heterogeneous, the histological classification of RCC in Japanese Urological Association (JUA) is designed to select only the dominant histological components. We evaluated whether this system could provide an adequate information concerning the prognosis of the patients. METHODS: Histological slides of 130 cases with RCC were microscopically evaluated. We classified these cases according to the JUA classification, and also checked the presence or absence of each histological components (3 cell types and 5 histological architectures) regardless of whether or not they were dominant. Univariate and multivariate analysis were then performed to determine the histological components which have prognostic impact on patient survival. RESULTS: Multivariate analysis demonstrated that only spinde/pleomorphic cells and solid architecture were the significant prognostic parameters. The presence of these histological components was not correctly shown in the JUA classification. CONCLUSION: The histological classification of RCC in JUA did not provide enough information about the presence of the important prognostic parameters. This system should be modified to describe all the histological components regardless of whether they are dominant or not.

Adult↗

Colposcopy, cytology and histology in the diagnosis of squamous intraepithelial lesions of the cervix.

OBJECTIVE: To compare colposcopic findings to cytologic and histological diagnoses in women with colposcopic reports of ANTZ and/or HPV infection. METHODS: Among 791 hospitalized women referred for colposcopic examination, colposcopy showed ANTZ grade 0-2 and/or HPV infection in 271 patients (34.26%). Only 153 were fully investigated by colposcopy, cytology (under colposcopic observation) and histology (target punch biopsy: 109 patients; surgical specimens of hysterectomy: 42 patients; conization: 2 patients). Cytological and histological diagnoses were reported according to the Bethesda System. RESULTS: 132/153 Pap smears were estimable for sampling adequacy; 44/63 resulted as normal and were histologically positive for LSIL [1]. Five LSIL-positive Pap tests were negative on histology (false negative and false positive rate of 33.33% and 3.78%). The pap test was diagnostic for intraepithelial neoplasia in 34/65 cases (53.3%) and for invasive cancer in 6/11 cases (54.5%). In 67/132 cases (50.8%) adequate-for-sampling Pap smears could not predict the exact diagnosis. On the other hand, 108/141 patients with colposcopic evidence of ANTZ/cancer showed histological SIL or invasive neoplasm (76.59%): ANTZ 1 was associated to LSIL and HSIL in 74.1% and 2.4%; ANTZ 2 to LSIL, HSIL and invasive cancer in 41%, 30.76% and 10.3%. Colposcopic suspicion of invasive cancer in 8 patients was histologically demonstrated in 7 (87.5%); colposcopic diagnosis of HPV infection was confirmed in 10/12 (83.4%). CONCLUSION: A better correspondance was shown between colposcopy and histology than between cytology and histology in the diagnosis of SIL. We suggest a routine colposcopy investigation for all patients admitted to a gynecological clinic and we believe it is very important to take Pap smears under colposcopic observation if colposcopy and cervical smears are performed in the same sitting.

Adult↗

Prognostic significance of histologic grading compared with subclassification of papillary thyroid carcinoma.

BACKGROUND: Papillary thyroid carcinomas represent a diversity of morphologic subtypes and variants, but to the authors' knowledge the prognostic significance of subclassification is not clear. Therefore, the authors compared the value of histologic classification with a combined assessment of histologic key features such as marked nuclear atypia, tumor necrosis, and vascular invasion (i.e., histologic grade). METHODS: One hundred twenty-eight surgically treated patients with papillary carcinoma > 10 mm were studied. The tumors were subclassified and individual histologic features were examined and compared in univariate and multivariate survival analyses. RESULTS: Of all the cases, 55% were of the usual type, whereas 27% showed complex histologic features with different components present and 18% represented specific subtypes. Tall cell differentiation showed an increased frequency of tumor necrosis and vascular invasion, and tumors with solid areas had an increased occurrence of mitotic figures and vascular invasion. Patients with tall cell tumors tended to have reduced survival (P = 0.074), and two patients with columnar cell features died of the disease. When combined, the group of patients with all tumor subtypes had significantly reduced survival when compared with the remainder of patients (P = 0.034), although the difference was only minor. Histologic grade was highly significant (P = 0.0001) in survival analysis, together with mitotic frequency (P = 0.028), S-phase (P = 0.015), and G(2)M-phase fractions (P = 0.040). In multivariate analysis, tumor dimension (P = 0.019) and histologic grade (P = 0. 008) showed significant and independent prognostic importance, whereas subclassification was not found to be significant. CONCLUSIONS: Subclassification of papillary thyroid carcinomas had only a minor prognostic impact, whereas histologic grade was a strong and independent prognostic marker. The authors recommend that all papillary carcinomas be given a histologic grade based on a combined examination of nuclear atypia, tumor necrosis, and vascular invasion. [See editorial on pages 1766-68, this issue.]

Adult↗

[Evaluation of histological criteria for bullous pemphigoid. Correlation with antigens recognized by immunoblotting of anti-epidermal autoantibodies].

The aim of this study was to evaluate the histological findings observed in patients with bullous pemphigoid in whom the diagnosis of bullous pemphigoid could be confirmed by direct immunofluorescence and immunoblot serum analysis. Seven histological criteria were considered for selection of skin biopsy specimens: 1) cleavage of dermal epidermal junction; 2) migration of eosinophils along dermal epidermal junction; 3) presence of intra epidermal eosinophils (with or without associated spongiosis); 4) absence of keratinocyte necrosis; 5) absence of acantholysis; 6) absence of dermal fibrosis; 7) absence of vasculitis. Depending on the number of criteria observed the histological picture was considered as: highly suggestive, suggestive or poorly suggestive of bullous pemphigoid. The histological picture was considered as highly suggestive in 50% of cases, suggestive or poorly suggestive in 37% and 13% of cases respectively. Migration of eosinophils along dermal epidermal junction was observed in 23 biopsy specimens (50%). Histological findings considered as poorly suggestive of bullous pemphigoid consisted of a prurigo-like or an eczematous-like or a drug induced-like picture or no specific cutaneous erosions. An histological picture highly suggestive of bullous pemphigoid was observed in 67% of patients whose serum contained anti-BPAG2 antibodies and in only 36% patients of without anti-BPAG2 antibodies (p=0,04). On the contrary, only one bullous pemphigoid patient (4%) with circulating anti-BPAG2 antibodies had a histological picture poorly suggestive of bullous pemphigoid. These findings are in accordance with the pathogenic properties of anti-BPAG2 antibodies demonstrated in animal models. This study showed that: 1) typical histological findings of bullous pemphigoid are only observed in 50% of skin biopsy specimens. 2) The diagnosis of bullous pemphigoid should be considered in elderly patients even when a poorly specific prurigo-like or eczematous-like histological picture is observed. Moreover, it underlines the usefulness of direct immunofluorescence of skin biopsy specimens and indirect immunofluorescence and immunoblot analysis of serum in such atypical cases of bullous pemphigoid.

Autoantibodies↗

Correlation of endoscopic and histologic findings before and after treatment for nasopharyngeal carcinoma

BACKGROUND: The endoscopic and histologic findings before and after radiotherapy (RT) for nasopharyngeal carcinoma (NPC) were correlated to study the sensitivity and specificity of endoscopic findings in predicting histologic results. The efficiacy of endoscopic examination and post-RT multiple site biopsies in detecting persistent disease was also evaluated. METHODS: Seven hundred forty-six patients were evaluated. Pre-RT, biopsies were taken from both sides of the nasopharynx to assess the extent of tumor. Four to 16 weeks after RT, routine six-site biopsy specimens were taken from both roofs, lateral, and posterior walls of the nasopharynx and repeated 2 weeks later. Endoscopic findings of exophytic growth, nodule, ulcer, and submucosal bulge were considered "residual tumor, " others were considered "no residual tumor." Persistent disease was defined as positive histologic findings 12 weeks after RT. RESULTS: Before RT, sensitivity of endoscopic findings and biopsy specimens in detecting malignancy were 99.7% and 94.2%, respectively. After RT, sensitivity and specificity of endoscopic findings in predicting positive histologic findings were 29% and 85.8%, respectively, with a positive predictive value of 34.9% and a negative predictive value of 82.2%. Of positive histologic findings, 27.7% were missed in the first session of biopsies; 33.5% of those with positive histologic findings turned out to have persistent disease. For prediction of persistent disease, the sensitivity and specificity of endoscopic findings were 40.4% and 84.4%, with a positive predictive value of 16.3% and a negative predictive value of 95%, and that of histologic findings in the first session of biopsies were 59.6% and 88.3%, respectively, with a positive predictive value of 27.7% and a negative predictive value of 96.7%. CONCLUSIONS: Endoscopic findings alone have low sensitivity in predicting persistent disease, multiple sites biopsy specimens are indicated. Because only 1.9% of patients with endoscopic findings of "no residual tumor" and negative histologic findings in first session of biopsies had persistent disease, this group can be spared second biopsies. Repeat biopsies are indicated for those with endoscopic findings of "residual tumor" or positive histologic findings in first session of biopsies to improve detection of persistent disease. Copyright 2000 John Wiley & Sons, Inc. Head Neck 23: 34-41, 20001.

Journal Article↗

Correlation of endoscopic and histologic findings before and after treatment for nasopharyngeal carcinoma.

BACKGROUND: The endoscopic and histologic findings before and after radiotherapy (RT) for nasopharyngeal carcinoma (NPC) were correlated to study the sensitivity and specificity of endoscopic findings in predicting histologic results. The efficiacy of endoscopic examination and post-RT multiple site biopsies in detecting persistent disease was also evaluated. METHODS: Seven hundred forty-six patients were evaluated. Pre-RT, biopsies were taken from both sides of the nasopharynx to assess the extent of tumor. Four to 16 weeks after RT, routine six-site biopsy specimens were taken from both roofs, lateral, and posterior walls of the nasopharynx and repeated 2 weeks later. Endoscopic findings of exophytic growth, nodule, ulcer, and submucosal bulge were considered "residual tumor," others were considered "no residual tumor." Persistent disease was defined as positive histologic findings 12 weeks after RT. RESULTS: Before RT, sensitivity of endoscopic findings and biopsy specimens in detecting malignancy were 99.7% and 94.2%, respectively. After RT, sensitivity and specificity of endoscopic findings in predicting positive histologic findings were 29% and 85.8%, respectively, with a positive predictive value of 34.9% and a negative predictive value of 82.2%. Of positive histologic findings, 27.7% were missed in the first session of biopsies; 33.5% of those with positive histologic findings turned out to have persistent disease. For prediction of persistent disease, the sensitivity and specificity of endoscopic findings were 40.4% and 84.4%, with a positive predictive value of 16.3% and a negative predictive value of 95%, and that of histologic findings in the first session of biopsies were 59.6% and 88.3%, respectively, with a positive predictive value of 27.7% and a negative predictive value of 96.7%. CONCLUSIONS: Endoscopic findings alone have low sensitivity in predicting persistent disease, multiple sites biopsy specimens are indicated. Because only 1.9% of patients with endoscopic findings of "no residual tumor" and negative histologic findings in first session of biopsies had persistent disease, this group can be spared second biopsies. Repeat biopsies are indicated for those with endoscopic findings of "residual tumor" or positive histologic findings in first session of biopsies to improve detection of persistent disease.

Adolescent↗

Prognostic impact of cathepsin D and c-erbB-2 oncoprotein in a subgroup of node-negative breast cancer patients with low histological grade tumors.

Some node-negative breast cancer patients, with initially good prognosis, relapse from their cancer and are poorly identified. In the present study, based on prospective data of 197 tumors, we measured cathepsin D (cath D, n=197), pS2 protein (n=125), c-erbB-2 oncoprotein (n=100) and epidermal growth factor receptor (EGF-R, n=99) to better define the risk of relapse of node-negative patients in comparison with that defined by the clinical and histological factors. The median follow-up in surviving patients was 75 months. Univariate analysis indicated that patients with histological grade III tumors (the Scarff, Bloom and Richardson classification) had a much poorer prognosis than those with histological grade I or II tumors (P=0.0027 for relapse-free survival and P=0.0156 for overall survival). When the population of node-negative patients was divided by tertiles, high cath D levels showed a significant association with an early relapse (P=0.0316). Using cut-off values, patients with high cath D (> or =25 pmol/mg protein) or c-erbB-2 oncoprotein (> or =4 Human Neu Unit/microg protein) levels, had a significant worse relapse-free survival (P=0.0147 and 0.0417, respectively). No prognostic information was supported by pS2 protein or EGF-R measurements. In multivariate analysis, histological grade, cath D and c-erbB-2 oncoprotein remained independent predictors of recurrence (P=0.005, 0.0361 and 0.0321, respectively). By combining low levels of cath D and c-erbB-2 oncoprotein in histological grade I or II tumors, we identified a subgroup of patients with a 100% relapse-free survival probability at 6 years of follow-up. Moreover, the subgroup of patients with histological grade I or II tumors and high values of both cath D and c-erbB-2 oncoprotein showed a prognosis as poor as the subgroup defined by histological grade III alone, respectively 66% and 70% relapse-free survival at 6 years of follow-up. In conclusion, the combination of conventional prognostic factor (histological grade) and biochemical factors (cath D and c-erbB-2 oncoprotein) enabled us to identify, in this preliminary study, a subgroup of patients having an increased risk of relapse in a group (node-negative patients with low histological grade tumors) considered as good prognosis.

Aged↗

[Do histologic changes of the upper renal pole in double ectopic ureterocele justify a conservative approach?].

The aim of this study was to review the histology of the upper pole segment in patients with duplex ectopic ureterocele to verify if a less aggressive surgery is justified in the prenatally diagnosed patients. We reviewed the histology of the upper pole segment of 15 consecutive patients with duplex system ectopic ureterocele treated between 1991 and 1999 at the Paediatric Surgery Unit of University Hospital of Messina. The diagnosis of duplex system ectopic ureterocele was made according to the criteria of the Section on Urology of the American Academy of Paediatrics. The histology specimens were assessed for dysplastic, inflammatory and obstructive changes. All 15 patients with duplex system ectopic ureterocele were surgically treated with heminephro-ureterectomy and the surgical specimens were histologically examined. Nine of the 15 patients were prenatally diagnosed. The histology of the upper pole segment of the 9 prenatally diagnosed showed in all patients segmental renal microcystic dysplasia, chondroid metaplasic islands and an inflammatory tubulo-interstitial nephropathy in 6 patients (66.6%) and in 2 (22.2%) nephroblastomatosis. The histology of six the postnatal postnatally diagnosed patients showed in all patients segmental multicystic renal dysplasia, inflammatory tubulo-interstitial nephropathy and segmental parenchymal scars. The upper pole histology of the patients with duplex ectopic ureterocele diagnosed prenatally did not show any evidence of reversible histological change. Considering the histology and the good outcome of patients treated with upper pole nephroureterectomy a less aggressive surgery with preservation of the upper pole does not seem justified.

Humans↗

Clinical interpretation of the histological typing of gastric cancer using endoscopic forceps biopsy.

BACKGROUND/AIMS: Histological typing of gastric cancer is important for determining the treatment strategy and predicting the prognosis. We compared the histological types obtained by endoscopic forceps biopsy with the finally determined histological types of surgically resected specimens to investigate the reliability of histologically typing gastric cancer by biopsy. METHODOLOGY: Agreement between the biopsy typing and the final histological typing based on the predominant histology of the resected tumor was studied in 115 consecutive gastric cancers. RESULTS: The overall agreement rate of histological typing of gastric cancer was 75.7%. In patients with early gastric cancer, the agreement rate was a high 82.5% and the final histological type was usually predicted. In patients with advanced gastric cancer, the agreement rate was 72.0%, which was significantly lower than for early gastric cancer (p<0.05). The agreement rate for advanced differentiated cancer was also significantly lower than that for early cancer (63.6% vs. 90.0%) (p<0.05). CONCLUSIONS: The reliability of using histological typing by biopsy to set the indications for endoscopic treatment and for preoperative prediction of the prognosis is expected to be good for differentiated early gastric cancer, but it might not be adequate for advanced cancer or undifferentiated cancer.

Adenocarcinoma↗

[Thyroid dysfunction and histologic correlation using thyroid needle biopsy specimens].

In this article, we describe the usefulness of thyroid needle biopsy in the differential diagnosis of thyroid disorders revealing unusual thyroid function. Firstly, we describe the relationship between thyroid function and its histology in 601 cases of chronic thyroiditis. In the histologic group A, the majority of the cases showed a latent or overt hypothyroidism and in histologic group B, hyperthyroid, euthyroid and latent hypothyroid cases were found in nearly equal frequency, respectively. In histologic group C, most cases were in euthyroid and in histologic group D, most cases showed a hyperthyroidism. In the silent thyroiditis and postpartum thyroiditis, known to show a characteristic clinical and laboratory finding, the histologic features of thyroid gland were as follows: the observed characteristic histologic changes in both diseases were an extensive follicular destruction associated with chronic diffuse thyroiditis. These destructive changes disappeared in association with the clinical and laboratory recovery. In the patients with iodine-excess hypothyroidism, the thyroid glands also revealed characteristic histologic changes. A marked hyperplastic change of follicular cells and a lack of colloid material in the follicular lumen was the predominant histologic feature. Based on our personal experiences, thyroid needle biopsy should be recommended as a useful tool for differentiation of causes of hyper- or hypothyroidism.

Adult↗

[Study on radiographic examination in the temporomandibular joint. Comparison between tomographic and histological findings].

Radiographic changes in the temporomandibular joint (TMJ) generally mean structural bone changes. However, the TMJ has a complex structure and comparisons of histological and radiographic findings are seldom seen in the literature. The author examined 14 human cadavers, 21 TMJs, with lateral tomography and studied the areas of the radiographs histologically. The results were as follows. 1. Radiographic erosion observed in the depression for the lateral pterygoid muscle and in the posterior part of the condyle generally showed no histological changes. Only two erosions, one in the superior part of the condyle and the other in the anterior slope of the articular fossa, showed histological changes. 2. Radiographic sclerosis observed in the articular eminence and the posterior slope of the fossa revealed no histological changes. Four cases of sclerosis in the superior part of the condyle showed remodelling of the bone. 3. Radiographic osteophyte observed in the antero-superior part of the condyle, revealed remodelling and morphological changes corresponding to the radiographic findings. 4. Radiographic flattening observed in the articular eminence revealed histological remodelling changes that corresponded to the radiographic findings. 5. Radiographic concavity observed in the posterior part of the condyle showed no histological changes in this area. However, remodelling of the bone was observed in the superior part of the condyle. In conclusion, radiographic flattening and osteophyte indicated structural bone changes directly. However radiographic erosion and sclerosis must be interpreted with caution, because many cases showed no histological changes and the localization of these radiographic findings was important. Radiographic concavity also must be interpreted with caution, because most cases revealed no depression histologically, but showed proliferation of the bone in front of this region. It was also suggested that the technical terms that express radiographic findings must be questioned and discussed still more.

Humans↗

[Histological study on radiosensitivity of cervical carcinoma with special reference to 3 subtypes of squamous cell carcinoma].

Morphological investigation were made on the radiosensitivity, according to the histological types; keratinizing(K), large cell nonkeratinizing(LNK), and small cell nonkeratinizing(S) type. The results obtained are as follows. Histological and cytological estimation of irradiated effects were examined at the 7th day after 10 Gray test-irradiation: (i) Histological studies were done with the biopsy specimens (76 cases): There were significant differences among 3 histological types (LNK greater than K greater than S, P less than 0.05). (ii) Cytological studies were done as well as histological ones (48 cases): There was a significance between two groups (LNK greater than S, K greater than S, P less than 0.05). (iii) There was a correlation between the histological and cytological irradiation effects. DNA histogram patterns were also examined spectrophotometrically. It seemed that the patterns after test-irradiation was broad and these peaks were situated rather to high ploidy in histologically and cytologically highly effective cases. Early ultrastructural findings after test-irradiation were as follows: (i) appearance of intra-nuclear "pseudoinclusion", (ii) swelling of mitochondria, endoplasmic reticulum, and so on. Although these characteristics presented the same sequence of events without regard to their histological types, they were not synchronized. It seemed that they appeared earlier after test-irradiation in histologically high-sensitivity cases than in low-sensitivity cases.

Carcinoma, Squamous Cell↗

Image-directed percutaneous biopsy with large-core needles. Comparison of cytologic and histologic findings.

Large biopsy needles (18 and 19 gauge) have been reported to yield high-quality tissue cores for reliable histologic diagnosis. In our institution, image-directed percutaneous biopsy specimens obtained with these needles are processed routinely for simultaneous cytologic and histologic analysis. For the present study, we reviewed our experience with 82 such biopsies of the thoracoabdominal region. We examined the value of cytologic analysis as a supplement to histologic analysis of such biopsies in terms of diagnostic yield and sensitivity for detecting malignancy. Among the 82 specimens, material was adequate for histologic diagnoses in 70 (85%) and for cytologic diagnosis in 63 (77%). Combining the histologic and cytologic results increased the diagnostic yield to 93% (76 of 82 specimens). Forty-eight lesions were diagnosed as malignant by either one or both means of analysis. While histologic analysis produced 44 of the 48 positive results (92%), cytologic analysis produced 33 (66%) (P < .05, McNemar's test). Because tissue fragments were selected preferentially for histologic processing, histologic evaluation was more valuable than cytologic evaluation in achieving definitive diagnoses of malignancy. In spite of this bias in preparation technique, malignancy was diagnosed by cytologic analysis alone in 4 of the 48 positive cases (8%). We conclude that the combined approach of histologic and cytologic examination of large-gauge core needle biopsy specimens maximizes the diagnostic yield and sensitivity for detecting malignancy.

Abdominal Neoplasms↗

Differences in manometry and 24-H ambulatory pH-metry between patients with and without endoscopic or histological esophagitis in gastroesophageal reflux disease.

UNLABELLED: In this study, our objective was to examine prospectively, by endoscopy and histology of the esophageal mucosa, the severity of reflux esophagitis and any possible correlation between endoscopic and histological findings on the one hand, and manometric and 24-h ambulatory pH-metry measurements on the other. Forty-two patients with gastroesophageal reflux were prospectively examined. The results were compared with those of 18 healthy controls. Methods used were: 1) upper alimentary endoscopy and grading of severity of esophagitis, 2) esophageal mucosa biopsies, to estimate severity of esophagitis on histology, 3) standard esophageal manometry, by using a water perfused catheter with four side holes, and 4) standard 24-h ambulatory esophageal pH-metry. RESULTS: The severity of esophagitis as determined by both endoscopy and histology was significantly inversely related to the amplitude (p < 0.001) and duration (p < 0.01) of esophageal peristalsis at 5 cm proximal to LES; it was significantly related to the pH-metry total composite score (p < 0.001 for endoscopy, p < 0.05-0.01 for histology), the total reflux time (p < 0.001 for endoscopy, p < 0.01 for histology), the duration of longest reflux episode (p < 0.001 for endoscopy, p < 0.01 for histology), the number of reflux episodes lasting more than 5 min (p < 0.05 for endoscopy), and the frequency-duration index of reflux episodes (p < 0.001 for endoscopy, p < 0.01 for histology). Furthermore, strength reduction of peristalsis (< 60 mm Hg x s) was associated with acid exposure greater than 40%, in esophagitis patients. We conclude that the severity of reflux esophagitis, not only through endoscopy but also histologically, is related to the amount of reflux, as expressed by the duration and frequency of the reflux episodes. A very high amount of reflux is in turn associated with impairment of the esophageal body motility, as expressed by the amplitude and strength of esophageal body peristalsis.

Adult↗

Quantitative histologic factors for grouping childhood supratentorial neuroglial tumors.

The histologic heterogeneity of childhood supratentorial neuroglial tumors, when quantified, identifies relatively homogeneous subgroups for prognostic purposes and for assignment in clinical trials. Our sample consisted of supratentorial tumors in the Childhood Brain Tumor Consortium. The data consist of reliably identified histologic features and demographic, clinical, operative, and survival information. Factor analysis was used to identify uncorrelated "factors," each represented by a different combination of histologic features in 703 tumors. The defining histologic features were used to label each factor. The heterogeneity of each tumor was summarized using the factor scores for each factor. We compared the survival estimates of subgroups of tumors within common diagnostic classes. We identified five uncorrelated quantitative factors that accounted for much of the histologic variation. Our factor labels were Jumbo, Fibrillary, Proliferative, Spongy, an Oligodendroglial. Two thirds of tumors had high scores on two or more factors, indicating a high degree of heterogeneity among these tumors. Eighty-four percent of supratentorial tumors were accounted for by 19 nonoverlapping relatively homogeneous histologic groups. The five quantitative factors complement standard qualitative taxonomies by summarizing more completely the histologic feature aspects of a tumor than by diagnosis alone and quantify the histologic heterogeneity of individual tumors. Histologically homogeneous groups of tumors are essential for clinical trials, biologic research, and prognostic models.

Adolescent↗

Laboratory instruction in histology at the University at Buffalo: recent replacement of microscope exercises with computer applications.

Histology is a morphologic science in which the structure of the cells, tissues, and organs of the body are examined with a microscope. In the laboratory courses in histology at the School of Medicine of the University at Buffalo, histologic specimens had been used since the late 19th century to teach the principles of cell, tissue, and organ structure. Students also had to learn how to analyze or "read" slides with a microscope. Learning histology in this way, i.e., by direct examination of actual specimens, is time consuming and viewed by some as unnecessary. As a result of recent curricular reform at the School of Medicine that reduced contact time in histology, half of all laboratory exercises that would have been performed with a microscope were performed instead with interactive computer applications. By replacing some microscope exercises with more efficient computer applications, the histology course accommodated curricular change by both reducing contact time and continuing to offer valuable microscope laboratories for most of the organ systems of the body. To provide a basis for comparing traditional microscope exercises with computer-assisted instruction in histology, the nature of the laboratory experience between 1846 and 1998 is briefly reviewed. The instructional strategy behind the use of computers is presented, along with the nature of the computer applications and the means by which the computer applications were incorporated into the school's laboratory course in histology.

Computer-Assisted Instruction↗

Trends in histology laboratory teaching in United States medical schools.

Owing to competition for faculty time among the three major missions of today's academic medical centers, as well as the rapid development of computer-based instructional technologies, laboratory instruction in medical schools in the United States has been undergoing dramatic change. In order to determine recent trends in histology laboratory instruction at U.S. medical schools, a detailed Web survey was administered to histology course directors, with about two-thirds of schools responding. The survey was designed to identify trends in the number of hours of histology laboratory instruction that each medical student receives, the amount of faculty effort devoted to histology laboratory instruction, and the use of various computer-based technologies (including virtual microscopy and virtual slides) in histology laboratory instruction. Consistent with the long-term trend of declining total laboratory teaching hours in U.S. medical schools, there is an ongoing reduction in the number of hours of faculty-directed histology laboratory instruction that each medical student receives, with a concomitant reduction in hours of faculty time devoted to histology laboratory instruction. In terms of the tools used in the histology laboratory, there has been a dramatic increase in the use of various forms of computer-aided instruction (including virtual slides). The large increase in the number of schools using computer-aided instruction has not been accompanied by an equivalent decrease in the number of schools that utilize microscopes and glass slides. Rather, the clear trend has been toward a blending of the new computer-based instructional technologies with the long-standing use of microscopes and glass slides.

Clinical Laboratory Techniques↗

Atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL) and histology.

OBJECTIVE: A new terminology for cytologic diagnosis of cervical lesions has been introduced by Bethesda System. This includes: 1) Atypical squamous cells of undetermined significance (ASCUS), 2) Low-grade squamous intraepithelial lesion (LSIL), 3) High-grade squamous intraepithelial lesion (HSIL), 4) squamo-cellular carcinoma. The aim of this study was to assess the correlation between the colpocytologic test (Pap psmear), the histologic response and colposcopy. METHODS: We re-examined the cytologic results of 447 patients who underwent routine cytologic tests, with a diagnosis of various grades of atypia, from ASCUS to HSIL. A histologic test was carried out on a colposcopic basis in 210 cases and cytologic results were correlated with the histologic and colposcopic pictures. RESULTS: For ASCUS the histology was positive in 19.1% (31/163) of cases and negative in 10.4% of the colposcopically positive cases (17/163), while in the remaining 70.5% (115/163) the colposcopy resulted negative. In LSIL with the presence of human papillomavirus (HPV) the histologic findings, confirmed the cytologic result in 35.8% (48/134) while in the group of cervical intraepithelial neoplasia (CIN I) results corresponded in 40.6% (41/101). In high squamous intraepithelial lesions there was an histologic confirmation in 59.2% (29/49). CONCLUSIONS: The data obtained indicate an increase in positive histology results from the types of low grade (ASCUS-LSIL) to those of a high grade (HSIL). Our results indicate that the presence of ASCUS should be assessed colposcopically and histologically, where indicated.

Adult↗